High-redshift quasars along the Main SequenceBased on observations collected at ESO under programmes 083.B-0273(A) and 085.B-0162(A).

A. Deconto-Machado,

A. del Olmo Orozco 1
P. Marziani 2
J. Perea 1
G. M. Stirpe 3

Instituto de Astrofísica de Andalucía, IAA-CSIC, E-18008, Granada, Spain
<EMAIL_ADDRESS><EMAIL_ADDRESS><EMAIL_ADDRESS>INAF, Osservatorio Astronomico di Padova, IT 35122, Padova, Italy
INAF, Osservatorio di Astrofisica e Scienza dello Spazio,
via Gobetti 93/3, 40129, Bologna, Italy

The 4-Dimensional Eigenvector 1 empirical formalism (4DE1) and its Main Sequence (MS) for quasars emerged as a powerful tool to organise the quasar diversity since several key observational measures and physical parameters are systematically changing along it.

The trends of the 4DE1 are very well established to explain all the diversity seen in low-redshift quasar samples. Nevertheless, the situation is by far less clear when dealing with high-luminosity and high-redshift sources. We aim to evaluate the behaviour of our 22 high-redshift ($2.2 \le z \le 3.7$) and high-luminosity ($47.39 \le L_{\textrm{bol}} \le 48.36$) quasars in the context of the 4DE1.

Our approach involves studying quasar physics through spectroscopic exploration of UV and optical emission line diagnostics. We are using new  observations from the ISAAC instrument at ESO-VLT and mainly from the SDSS  to cover the optical and the UV rest-frames, respectively.

Emission lines are characterised both through a quantitative parametrisation of the line profiles,
and by decomposing the emission line profiles using multicomponent fitting routines.

We provide spectrophotometric properties and line profile measurements for +, as well as for +OIV]$\lambda$1402, +HeII$\lambda$1640, 1900 Å blend (including , SiIII]$\lambda$1892, and CIII]$\lambda$1909). Six out of the 22 objects present a significant blueshifted component on the H$\beta$ profile, and in 14/22  cases an H$\beta$ outflowing component associated to  is detected.
The majority of  emission line profiles show blueshifted  velocities larger than 250 km s$^{-1}$.

We reveal extremely broad  emission that is comparable to the width of  broad profile in some highly accreting quasars.  and  blueshifts show very high amplitudes and a high degree of correlation.
Line width and shift are correlated for both  and , suggesting that emission from outflowing gas is providing a substantial broadening to both lines.  Otherwise,   the links between  centroid velocity at half intensity ($c$(1/2)), Eddington ratio (L/L$_{\textrm{Edd}}$), and bolometric luminosity are found to be in agreement with previous studies of high-luminosity quasars.

Our analysis suggests that the behaviour of quasars of very high luminosity all along the main sequence is strongly affected by powerful outflows involving a broad range of spatial scales.

The main sequence correlations remain valid
at high redshift and high luminosity even if a systematic increase in line width is observed.    Scaling laws based on UV AlIII$\lambda1860$ and  emission lines are equally reliable estimators of $M_{\rm{BH}}$.

§ INTRODUCTION

The nature of the many differences seen in quasar spectra has been a topic of interest for astronomers for many years and it is still a topic under discussion. One of the first successful attempts to define the systematic trends of quasar spectra was carried out by [Boroson & Green, 1992]. These authors have organised the relations between the optical and radio spectral ranges into an Eingenvector 1 scheme from studying the 80 quasars from the Palomar-Green sample [Schmidt & Green, 1983] using principal component analysis (PCA). This scheme considers mainly the anticorrelation seen between the optical FeII strength and peak intensity of the  emission line, and the full width at half-maximum (FWHM) of the broad component of H$\beta$ (H$\beta_{\rm BC}$, typically $\gtrsim 4000$ km s$^{-1}$). A more overarching possibility for the arrangement of the individual characteristics found in the quasar spectra has been suggested by [Sulentic et al., 2000] and takes into account several observational measures in the optical, UV, and X-ray spectral ranges as well as physical parameters such as outflow relevance and accretion mode. According to those authors, one can organise the quasar diversity into a fourth dimensional correlation space known as Eigenvector 1 (4DE1).

One of the four key parameters considered by the 4DE1 is the FWHM of the Hydrogen  broad component. Since the emission of Balmer lines like  are thought to be arising from the quasar Broad Line Region (BLR), this parameter can be used to measure black hole mass assuming gas to be virialised <cit.>.

The 4DE1 also considers as a parameter the ratio between the intensities of the blend of FeII emission lines at 4570Å and   ($R_{\ion{Fe}{II}}=I(\ion{Fe}{II}\lambda4570)/I(\rm H\beta)$), which can be used for the estimation of physical properties of the BLR such as the ionisation state, the electron density, and the column density of the ionised gas [Ferland et al., 2009, Panda et al., 2020].

The other parameters of the 4DE1 are the blueshifts of high-ionisation lines (HIL) with respect to the quasar systemic redshift and the soft X-ray photon index ($\Gamma_{\rm soft}$). HIL like the  emission line for instance are considered a strong diagnostic of outflows and there is some evidence that the optical and UV properties are related [Bachev et al., 2004, Du et al., 2016, Śniegowska et al., 2020]. Similarly, the equivalent width of the optical FeII contribution is seen as a measure of the thermal emission from the accretion disc [Singh et al., 1985, Walter & Fink, 1993].
The $R_{\ion{Fe}{II}}$, the soft X-ray photon index and the line width of  are also significantly correlated among themselves [Wang et al., 1996, Boller et al., 1996, Sulentic et al., 2000].

Exploration of the distribution of low-redshift ($z\!\lesssim\!0.8$) quasars in the optical plane of the 4DE1, defined by FWHM(H$\beta_{\rm BC}$) vs. $R_{\ion{Fe}{II}}$ and called Main Sequence (MS) of quasars, gave rise to the identification of two main populations with very significant differences between their spectra [Zamfir et al., 2010]. Population A quasars show low FWHM (usually $\le 4000$ km s$^{-1}$) and a wide range of $R_{\ion{Fe}{II}}$, while Population B sources present a very wide range of FWHM(H$\beta_{\rm BC}$) but usually small $R_{\ion{Fe}{II}}$ ($\le 1.$). [Marziani et al., 2018] summarise more than 15 years of discussion on the empirical parametrisation of the quasar properties and their trends as well as on how physical parameters related to the accretion rate and feedback seem to be changing along the MS, going from quasars with low FeII emission and high black hole mass ($\gtrsim 10^9$ M$_{\odot}$, Pop. B) to the extreme Pop. A, xA [Martínez-Aldama et al., 2018], with strong FeII emission ($R_{\rm{\ion{Fe}{II}}}>1$) and strong blueshifts in High-Ionisation Lines (HIL) as  indicating strong wind effects on the quasars <cit.>.

Eddington ratio together with the orientation effect are seen as key properties in the MS context [Sulentic et al., 2000, Marziani et al., 2001, Boroson, 2002, Shen & Ho, 2014, Sun & Shen, 2015].   The $R_{\ion{Fe}{II}}$ parameter together with the H$\beta_{\rm BC}$ FWHM can be associated with $L/L_{\rm Edd}$ (Marziani et al., 2001, Panda et al., 2019). Low values of the  (typically $\lesssim$ 0.2) are usually found in Pop. B sources, while Pop. A sources are found to be high accretors (in extreme cases reaching  $\gtrsim 1$).  Consequently, sources with the highest $R_{\ion{Fe}{II}}$ are thought to be the ones with the highest Eddington ratio.
Consistent results are also reported by [Du et al., 2016], which denote the strong correlation found between Eddington ratio, shape of the broad profile of the H$\beta$ emission line, and the flux ratio $I$(H$\beta$)/$I$(FeII) as the fundamental plane of accreting black holes. According to those authors, the shape of both Lorentzian and Gaussian profiles may reveal details on the BLR dynamic and may be different depending on the Eddington ratio <cit.>. Regarding the width of the emission line profiles, the broadest sources that are more Gaussian-like due to a redward asymmetry can be seen as the sum of two Gaussian (usually a BC and a very broad component, VBC) and the sources which present a VBC, usually with FWHM $> 7000$ km s$^{-1}$, are the ones which show lower Eddington ratio [Marziani et al., 2003, Marziani et al., 2019]. However, the line width  is believed to be highly influenced by source orientation and the Eddington ratio [Marziani et al., 2001, McLure & Jarvis, 2002, Zamfir et al., 2008, Panda et al., 2019]. Since it is likely that  lines are emitted by flattened systems, orientation may affect the FWHM(H$\beta$), going from broader (bigger $\theta$, with $\theta$ indicating the inclination of the source with respect to the line-of-sight) to narrower (smaller $\theta$) profiles.

Of special relevance is also the issue of sources that are radio-loud. Only about 10% of quasars are strong emitters in radio. [Zamfir et al., 2010] have analysed $\sim 470$ low-redshift (z < 0.8) quasars from the SDSS DR5 [Adelman-McCarthy et al., 2007] and found that in general the radio-loud sources are located in the Pop. B domain of the MS, while the radio-quiet are found in both populations. The location of the radio-loud (RL) quasars seems to indicate different properties with respect to a large fraction of the radio-quiet (RQ) sources. However, the fact that the RQs are distributed in both populations A and B complicates the interpretation. For instance, radio-loud and a large fraction of radio-quiet quasars both present strong asymmetries towards red wavelengths in the emission line profiles [Marziani et al., 1996, Punsly, 2010]. The paucity  of radio-loud Population A sources at low-$z$ implies that  the Eddington ratio and the black hole mass distributions are different for radio-quiet and radio-loud sources matched in redshift and luminosity [Woo & Urry, 2002, Marziani et al., 2003, Fraix-Burnet et al., 2017]. In the two cases, the radio-quiet quasars are the ones that usually present smaller masses and larger Eddington ratio.
This is not necessarily true for sources at high-redshift [Sikora et al., 2007, Marinello et al., 2020, Diana et al., 2022].

The 4DE1 formalism and especially the MS represent the most effective way to distinguish quasars according to their BLR structural and kinematic differences. It has been extensively analysed in samples at $z<0.8$ <cit.>. Trends between the optical plane of the 4DE1 and the $L/L_{\rm Edd}$ (for instance, sources with strong $L/L_{\rm Edd}$ are usually found to have strong ) are also seen in high-luminosity high- and intermediate-redshift sources <cit.>. However, high-$z$ quasar samples that have been studied  including NIR observations of the  spectral range  are relatively few <cit.>.  One of the studies of high-$z$ quasars under this context has been performed by <cit.>. They analyse the optical region of 53 Hamburg-ESO sources in a redshift range $z\approx 0.9 - 3.0$ using VLT ISAAC spectra <cit.>. Additional UV spectra were obtained for some of these sources and the results are reported by <cit.>. The authors found that both Pop. A and Pop. B quasars present evidences of significant outflows at high redshift while at low $z$ only Pop. A sources tend to show strong contribution of outflowing gas. Extreme Pop. A quasars (xA) in a redshift range of $z=2.0-2.9$ and with an averaged bolometric luminosity of $\log L \sim 47$ [erg s$^{-1}$] have been analysed in details on the UV region by [Martínez-Aldama et al., 2018] using GTC spectra. These authors found that the xA sources at high $z$ share the same characteristics of the sources at low redshift, albeit with the higher outflow velocities (reaching values of $\sim 4000$ km s$^{-1}$).

In this paper new observations from VLT/ISAAC are reported for 22 high-redshift and high-luminosity quasars and the data analysis of the UV and optical regions along the Main Sequence is performed and discussed. Our goal is to improve the sampling of the MS and the understanding of high-$z$, high-luminosity quasars. In order to do so, we take advantage of previous high- and low-$z$ samples and perform a comparison between the different data under the 4DE1 context. Details on the sample and on the observations are presented in Sect. <ref> and <ref>. The procedures and the approach followed during the line decomposition are presented in detail on Sect. <ref>. Results on the complete analysis of both optical (+) and UV (SiIV$\lambda$1392, , and the 1900 Å blend) regions are reported in Sect. <ref> and additional discussions are provided in Sect. <ref>. In Sect. <ref> we list the main conclusions of our work.

[]Source identification.

Source      RA (J2000)     DEC (J2000)     z     $\delta$z     $m^{(b)}$     Band     $M_{\mathrm{i}}$     $m_{\mathrm{VCV10}}$     $f_{\textrm{Radio}}$ (mJy)$^{(h)}$     Survey     Radio Class.

(1)     (2)     (3)     (4)     (5)     (6)     (7)     (8)     (9)     (10)     (11)     (12)

HE 0001-2340     00 03 44.95     -23 23 54.7     2.2651$^{(a)}$     0.0036     14.78     H     -29.68     16.70$^{(c)}$      $<2.70$     NVSS     RQ

$[\rm HB89]$ 0029+073     00 32 18.37     +07 38 32.4     3.2798$^{(a)}$     0.0055     15.12     K     -29.26     17.44$^{(d)}$     $<0.86$     FIRST     RQ

CTQ 0408     00 41 31.49      -49 36 12.4     3.2540     0.0048    14.02     K     -29.86     16.10$^{(d)}$     7.26     SUMSS     RI

SDSSJ005700.18+143737.7     00 57 00.19     +14 37 37.7     2.6638     0.0023     15.70     H     -29.06       17.96$^{(e)}$     $<2.70$     NVSS     RQ

H 0055-2659     00 57 57.92     -26 43 14.1     3.6599     0.0062     15.50     K     -30.74     17.47$^{(f)}$     $<2.70$     NVSS     RQ

SDSSJ114358.52+052444.9     11 43 58.52     +05 24 44.9     2.5703     0.0038     15.54     H     -29.47     17.27$^{(e)}$     $<0.96$     FIRST     RQ

SDSSJ115954.33+201921.1     11 59 54.33     +20 19 21.1     3.4277     0.0068     15.13     K     -29.92     17.92$^{(e)}$     $<0.97$     FIRST     RQ

SDSSJ120147.90+120630.2     12 01 47.91     +12 06 30.2     3.5136     0.0063      14.60     K     -29.76     18.16$^{(e)}$     $<0.98$     FIRST     RQ

SDSSJ132012.33+142037.1     13 20 12.34     +14 20 37.1     2.5356     0.0023     15.52     H     -28.87     17.82$^{(e)}$     $<0.98$     FIRST     RQ

SDSSJ135831.78+050522.8     13 58 31.79     +05 05 22.7     2.4627     0.0020     15.40     H     -29.21     17.33$^{(e)}$     $<0.94$     FIRST     RQ

Q 1410+096     14 13 21.05     +09 22 04.8     3.3240     0.0029     14.83     K     -29.44     17.80$^{(g)}$      $<0.99$     FIRST     RQ

SDSSJ141546.24+112943.4     14 15 46.23     +11 29 43.4     2.5531     0.0043     14.53     H     -29.40      17.23$^{(e)}$    7.80     NVSS     RI

B1422+231     14 24 38.10     +22 56 01.0     3.6287     0.0031     12.66     K     -29.85     15.84$^{(e)}$     273.42     FIRST     RL

SDSSJ153830.55+085517.0     15 38 30.55     +08 55 17.1     3.5554     0.0060     14.72     K     -30.07      17.98$^{(e)}$     $<1.02$     FIRST     RQ

SDSSJ161458.33+144836.9     16 14 58.34     +14 48 36.9     2.5698     0.0022     15.23     H     -29.41     17.43$^{(e)}$     $<0.94$     FIRST     RQ

PKS 1937-101     19 39 57.30     -10 02 41.0     3.7908     0.0032     13.81     K     -30.40     17.00$^{(g)}$     838.30     NVSS     RL

PKS 2000-330     20 02 24.00     -32 51 47.0     3.7899     0.0033     15.15     K     -30.99     17.30$^{(g)}$     446.00     NVSS     RL

SDSSJ210524.49+000407.3     21 05 24.47     +00 04 07.3     2.3445     0.0020     14.59     H     -29.96     16.98$^{(e)}$     3.20     NVSS     RI

SDSSJ210831.56-063022.5     21 08 31.56     -06 30 22.6     2.3759$^{(a)}$     0.0016     15.77     H     -29.11     17.41$^{(e)}$     $<1.18$     FIRST     RQ

SDSSJ212329.46-005052.9     21 23 29.46     -00 50 52.9     2.2800     0.0017     14.61     H     -29.76     16.62$^{(e)}$     $<0.96$     FIRST     RQ

PKS 2126-15     21 29 12.10     -15 38 42.0     3.2987     0.0042     14.22     K     -29.88     17.00$^{(g)}$     589.70     NVSS     RL

SDSSJ235808.54+012507.2     23 58 08.62     +01 24 34.8     3.4009     0.0029     14.84     K     -29.58      17.50$^{(d)}$     $<0.96$     FIRST     RQ

$^{(a)}$ Redshift estimation based on the $[\ion{O}{III}]\lambda 5007$. $^{(b)}$ 2MASS magnitude. $^{(c)}$ $m_{\rm{O}}$. $^{(d)}$ $m_{\rm{R}}$. $^{(e)}$ $m_{\rm{B}}$. $^{(f)}$ Photographic $m_{\rm{B}}$. $^{(g)}$ $m_{\rm{V}}$. $^{(h)}$ Values with $<$ are upper limits.

§ SAMPLE

The sample consists of 22 quasars with high redshift, going from $z=2.2$ to $z=3.7$, and high luminosity (47.39 $\le  \log L_{\textrm{bol}}\le$ 48.36 [erg s$^{-1}$]), including both radio-loud and radio-quiet sources that were observed under the ESO programmes 083.B-0273(A) and 085.B-0162(A). These sources were selected from the Hamburg-ESO survey (HE,  Wisotzki et al., 2000), which consists of a flux limited ($m_{\rm{B}}\approx 17.5$), color-selected survey with a redshift range $0 \lesssim z \lesssim 3.2$. Our sample presents a redshift that allows for the detection and observation of the + region through the transparent window in the near-infrared with the ISAAC spectrograph at VLT [Sulentic et al., 2006, Sulentic et al., 2017]. There is also a cut in $\delta$ at +25 degrees due to the geographic location of the telescope. Table <ref> presents the main properties of our sample, reporting the source identification according to the different catalogues (Col. 1); right ascension and declination at J2000 coordinates (Cols. 2 and 3, respectively); redshift estimated as explained in Section <ref> (Col. 4); redshift uncertainties (Col. 5); the $H$- or $K$-band (depending on the range of the spectrum) apparent magnitude $m_\mathrm{H}$ or $m_\mathrm{K}$ from the 2-MASS catalogue (Col. 6); the respective band (H or K, Col. 7); the $i$-band absolute magnitude $M_\mathrm{i}$ (Col. 8) estimated for our data; the apparent magnitude from Véron-Cetty & Véron, 2010 (Col. 9); the radio flux in mJy (Col. 10) in the frequency of the survey listed in Col. 11; radio classification according Ganci et al., 2019 is shown in Col. 12  and explained in section <ref>.

The $k$-correction used is the one available on [Richards et al., 2006] for sources with similar redshift and the galactic extinction were collected from the DR16 catalogue [Lyke et al., 2020].  The luminosity distance was computed from the redshift using the approximation of Sulentic et al., 2006, valid for $\Omega_\mathrm{M}=0.3$, $\Omega_{\Lambda}=0.7$, and H$_{\rm{0}}=70$ km s$^{-1}$ Mpc$^{-1}$.

For all sources, we have computed synthetic magnitudes $H$ or $K$  from our flux-calibrated spectra, and we have compared them  with the 2MASS $H$- and $K$-band apparent magnitudes. In cases in which the difference between our $m$ synthetic magnitudes and the 2MASS catalogue magnitudes is higher than 0.5 mag we use the $m$ from 2MASS (these sources are identified in Table <ref>). Also, in one very special source (B1422+231) a magnification correction is applied lowering the flux by a factor 6.6, which leads to a change in the magnitude, since this source is a gravitationally lensed quasar with four images ([Patnaik et al., 1992, Assef et al., 2011]; see Appendix <ref> for notes on individual objects). Apart from the well-known lensed quasar  B1422+231, our sample includes other quasars known or suspected to undergo micro-lensing: SDSSJ141546.24+112943.4 [Sluse et al., 2012, Takahashi & Inoue, 2014] and some  candidates, as $[\rm HB89]$ 0029+073 [Jaunsen et al., 1995], but we did not apply any magnitude correction for lensing on these sources.

Location of the complete sample in the Hubble diagram (pink spots). Gray dots represent a random subsample of the DR16 catalogue from [Lyke et al., 2020] and green, yellow, and blue dots represent the comparison samples defined in Section <ref>.

§.§ Redshift estimations and sample location in the Hubble diagram

Redshift measurements were  based on the H$\beta$ emission line profile, and were obtained from the observed wavelength of the  narrow component (FWHM $\lesssim 1000$ km s$^{-1}$). The values are reported in Table <ref>. In the case of HE 0001-2340 and SDSSJ210831.56-063022.5 the redshift was estimated through the [Oiii]$\lambda 5007$ emission line, due to the difficulty of isolating a narrow component of H$\beta$. Before performing the spectral analysis, described in section <ref>, both optical and UV spectra are set at rest-frame using the IRAF task .

Fig. <ref> shows the location of the objects of the sample (pink spots) in the $i$-band absolute magnitude $M_{\rm{i}}$ vs. redshift plane. Our sample as well as the comparison samples (defined in Section <ref>) are located at the high end of the luminosity distribution when compared with the SDSS DR16 data (grey spots, Lyke et al., 2020). Moreover, some of our sources are well located within the region with the highest values of the SDSS redshift distribution for quasars.

§.§ Comparison samples

We have chosen comparison samples that include high- and low-redshift, as well as high- and low-luminosity sources that were studied in the recent literature, as follows:

* Low-$z$ SDSS sources: [Zamfir et al., 2008] and  [Zamfir et al., 2010] analyse $\sim$ 470 low-redshift ($z\le 0.7$)  quasars with high signal-to-noise (S/N $\sim 29$) ratio optical spectra observed  with the Sloan  Digital  Sky  Survey data release (DR) 5 [Adelman-McCarthy et al., 2007], including both radio-loud and radio-quiet sources. This sample covers a wide range of bolometric luminosity, going from $\log L_{\rm{bol}}= 10^{43}$ to $\log L_{\rm{bol}}= 10^{47}$ erg s$^{-1}$.

* High-luminosity Hamburg-ESO sample (hereafter, HEMS):  [Sulentic et al., 2004, Sulentic et al., 2006] and [Marziani et al., 2009] obtained, using the VLT-ISAAC camera, H$\beta$ region measurements for a sample of 53 high-redshift high-luminosity objects, selected from the Hamburg-ESO  survey. The sources are extremely luminous (47$\lesssim L_{\textrm{bol}}\lesssim$ 48) and are located in a redshift range of $0.9 \lesssim z \lesssim 3.1$. We use these data as comparison sample at high $L$, for both H$\beta$ and [OIII] lines.  For the UV region we use the results provided by [Sulentic et al., 2017], who studied 28 quasars of the previous sample, and from which they obtained CIV$\lambda1549$ observations with the VLT and  TNG telescopes.  The redshift range of the HEMS is $1.4 \le z \le 3.1$ and a typical bolometric luminosity is $L_{\rm bol} \gtrsim 10^{47.5}$ erg s$^{-1}$. The  location of the HEMS in the Hubble diagram is similar to the one of our data (Fig. <ref>) in terms of absolute magnitudes, although a large fraction of HE sources is with $1 \lesssim z \lesssim 2$.

* Low-luminosity FOS data: The low-luminosity Faint Object Spectrograph (FOS) comparison sample was selected from <cit.>, where the authors analysed the CIV line parameters. <cit.> provide measurements on the H$\beta$ emission line for most sources in this sample. The typical bolometric luminosity of this sample is $\log L_{\rm{bol}} \sim 45.6$ [erg s$^{-1}$] and a redshift range $z \le 0.5$.

§ OBSERVATIONS AND DATA

[]Log of optical observations with VLT/ISAAC.

Source                Date obs.     Band     DIT     N$_{\rm{exp}}$     Airmass     Averaged

(start)                (s)              start-end     seeing

(1)     (2)     (3)     (4)     (5)     (6)     (7)

HE 0001-2340          2010-07-06     sH      180     12       1.05-1.02     1.03

2010-07-24     sH      180     12       1.03-1.01     0.55

2010-08-04     sH      180     12       1.06-1.12     1.44

$[\rm{HB89}]$ 0029+073       2009-09-03     sK      180     20       1.43-1.25     1.08

2010-07-08     sK      180     20       1.25-1.19     0.49

2010-08-04     sK      180     20       1.19-1.18     1.31

CTQ 0408               2009-07-09     sK      180      8       1.11-1.12     0.51

2009-08-31     sK      180      8       1.11-1.12     3.05

SDSSJ005700.18+143737.7       2009-09-04     sH      180     28       1.44-1.98     1.99

H 0055-2659           2009-09-02     sK      180     40       1.01-1.23     1.25

SDSSJ114358.52+052444.9       2009-07-08     sH      180     20       1.34-1.67     0.83

SDSSJ115954.33+201921.1       2010-04-05     sK      175     24       2.35-1.69     1.08

SDSSJ120147.90+120630.2       2010-04-15     sK      180     20       1.92-1.49     1.23

SDSSJ132012.33+142037.1       2009-05-04     sH      180     24       1.36-1.28     1.37

SDSSJ135831.78+050522.8       2010-04-18     sH      180     20       1.23-1.18     0.73

Q 1410+096            2010-04-20     sK      180     28       1.45-1.23     0.83

SDSSJ141546.24+112943.4       2009-05-04     sH      180     20       1.24-1.26     0.50

B1422+231            2009-04-13     sK      180     12       1.50-1.48     0.98

SDSSJ153830.55+085517.0       2010-04-05     sK      180     20       1.20-1.24     1.14

SDSSJ161458.33+144836.9       2009-07-08     sH      180     20       1.33-1.30     1.35

2009-09-22     sH      180     20       1.73-2.05     2.24

PKS 1937-101          2009-09-03     sK      180     12       1.13-1.23     1.07

PKS 2000-330          2009-08-31     sK      180     20       1.43-1.89     2.03

SDSSJ210524.49+000407.3       2010-07-23     sH      180     12       1.29-1.45    1.80

SDSSJ210831.56-063022.5       2010-06-19     sH      175     24       1.07-1.18     0.93

SDSSJ212329.46-005052.9       2010-07-08     sH      180     12       1.12-1.18     0.48

2010-07-24     sH      180     12       1.41-1.27     0.90

PKS 2126-15           2009-09-01     sK      180      12       1.84-2.36     1.41

2010-06-09     sK      180     16       1.26-1.12     1.07

SDSSJ235808.54+012507.2           2010-06-21     sK      180     20       1.25-1.13     1.01

§.§ Near Infrared Observations and data reduction

Spectra were taken in service mode in 2009 and 2010, with the infrared spectrometer ISAAC, mounted at the Nasmyth B focus of VLT-U1 (Antu) until August 2009, and later at the Nasmyth A focus of VLT-U3 (Melipal) at the ESO Paranal Observatory. Table <ref> summarises the NIR observations, listing the date of observation (Col. 2), used grating (Col. 3), individual Detector Integration Time (DIT) in seconds (Col. 4), number of exposures with single exposure time equal to DIT (Col. 5), the range of air mass of the observations (Col. 6), and the averaged seeing (Col. 7). When the source was observed more than once (HE 0001-2340, [HB89] 0029+073, CTQ 0408, SDSSJ161458.33+144836.9, SDSSJ212329.46-005052.9, and PKS 2126-15), we combine the individual spectra to obtain a median weighted final spectrum for the analysis. Spectral resolutions are FWHM $= 16$ Å in the $H$ band and FWHM $= 22$ Å in the $K$ band.

Reductions were performed using standard IRAF routines. Several spectra of each source were taken, nodding the telescope between two positions (nodding amplitude = 20”). Each obtained frame was divided by the flat field provided by the ESO automated reduction pipeline. 1D spectra were extracted using the IRAF program “apall”. Cosmic ray hits were eliminated by interpolation using a median filter, comparing the affected spectrum with the other spectra of the same source.

For each position along the slit, a 1D xenon/argon arc spectrum was extracted from the calibration lamp frame, using the same extraction parameters as the corresponding target spectrum. The wavelength calibration was well modeled by 3rd order Chebyshev polynomial fits to the positions of 15-30 lines, with rms residuals of 0.3 Å in sH and 0.6 Å in sK. The wavelength calibration is usually affected by a small 0-order offset caused by grism and telescope movement, because the arc lamp frames were obtained in daytime. A correction for these shifts was obtained by measuring the centroids of 2–3 OH sky against the arc calibration and calculating the average difference, which reached at most 2-3 pixels in either direction. Once matched with the corresponding arc calibrations, the individual spectra of each source were rebinned to a common linear wavelength scale and stacked.

The spectra of the atmospheric standard stars were extracted and wavelength-calibrated in the same way. All clearly identifiable stellar features (H and HeI absorption lines) were eliminated from the stellar spectra by spline interpolation of the surrounding continuum intervals. Each target spectrum was then divided by its corresponding standard star spectrum in order to correct for the atmospheric absorption features. This was achieved with the IRAF routine “telluric”, which allows to optimise the correction with slight adjustments in shift and scaling of the standard spectrum.
The correct flux calibration of each spectrum was achieved by scaling it according to the magnitude of the standard star and to the ratio of the respective DITs. Because the seeing often exceeded the width of the slit, significant light loss occurred, and therefore the absolute flux scale of the spectra is not to be considered as accurate. However, in this long-wavelength range we consider the light losses to be independent of wavelength (i.e., we assume that differential atmospheric refraction is negligible), and they should therefore not affect the relative calibration of the spectra. We carried out an a posteriori evaluation of the absolute flux calibration uncertainty  performing a comparison between the $H/K$-band magnitudes estimated by convolving the $H/K$ filter with the observed spectrum and the $H/K$ magnitudes in NED. The  differences are smaller than 0.5 mag, except for SDSSJ132012.33+142037.1, SDSSJ141546.24+112943.4, and SDSSJ153830.55+085517.0 where a correction  factor $\sim 0.880\pm0.176$ mag was applied.

[]UV spectra information.

Source      UV     Comments

(1)     (2)     (3)

SDSSJ005700.18+143737.7     BOSS

SDSSJ114358.52+052444.9     BOSS

SDSSJ115954.33+201921.1     SDSS

SDSSJ120147.90+120630.2     BOSS

SDSSJ132012.33+142037.1     BOSS

SDSSJ135831.78+050522.8     BOSS

Q 1410+096     SDSS     BAL

SDSSJ141546.24+112943.4     SDSS     BAL

SDSSJ153830.55+085517.0     BOSS     BAL$^{(a)}$

SDSSJ161458.33+144836.9     BOSS

PKS 2000-330     [Barthel et al., 1990]

SDSSJ210524.49+000407.3     SDSS     BAL

SDSSJ210831.56-063022.5     SDSS

SDSSJ212329.46-005052.9     BOSS

SDSSJ235808.54+012507.2     BOSS

$^{(a)}$ In this case, there is only a small but significant absorption close to  and do not affect the other UV emission lines that we are considering in the fittings.

§.§ UV

We have found useful UV spectra (i.e., which include at least one of the three UV regions of our interest) for the 15/22 sources that are listed in Table <ref>, where we also list in Col. 2 the database/reference from which each spectrum was obtained and in Col. 3 the Broad Absorption Lines (BAL) quasars. We report the BAL sources as the analysis of the region in which the broad absorptions are located should be taken with care, once it demands the addition of absorption components in the fitting routine. The other seven quasars do not have useful UV spectra, either because they are old spectra not digitally available and have low S/N not suitable for accurate profile fitting, or because they do not include any of the three UV regions we want to analyse (+OIV$\lambda$1402, +, and the 1900 Å blend). For the UV spectral range (observed in the optical domain at the redshift of this sample), the spectra were collected mainly from the SDSS DR16 database <cit.>. For one source (PKS 2000-330), the UV spectrum was digitalized from [Barthel et al., 1990]. Four out of the 22 quasars (Q 1410+096, SDSSJ141546.24+112943.4, SDSSJ153830.55+085517.0 and SDSSJ210524.49+000407.3) are classified as BAL quasars, due to strong absorption lines [Gibson et al., 2009, Scaringi et al., 2009, Allen et al., 2011, Welling et al., 2014, Bruni et al., 2019, Yi et al., 2020].

§.§ Radio data

The radio fluxes presented in Table <ref> were collected from the 1.4-GHz NRAO VLA Sky Survey (NVSS, [Condon et al., 1998]) and from the VLA FIRST Survey [Gregg et al., 1996, Becker et al., 1995]. The flux in radio is reported for seven of our sources and in the case the object is not detected we provide an upper limit to the flux, which corresponds to the detection limit ($\approx$ 5 times the rms in both FIRST and NVSS catalogue) at the position of the source. In the case of CTQ 0408, there is no coverage either in the FIRST survey or in the NVSS survey. The radio flux for this source is obtained at 408MHz from the Sidney University Molonglo Sky Survey catalogue [Mauch et al., 2003].  The radio classification is shown in Col. 12 of Table <ref> and it was determined following Ganci et al., 2019 through the estimation of a modified rest-frame radio loudness parameter $R_{\rm{K}}={f_{\rm{\nu,radio}}/f_{\rm{\nu,optical}}}$ [Kellermann et al., 1989], defined as the ratio between the specific flux at 1.4 GHz and in the $g$-band. Accordingly, our sample is separated into three different ranges: radio-quiet (RQ; $R_{\rm{K}}<10$), radio-intermediate (RI; $10 \leq R_{\rm{K}}<70$), and radio-loud (RL; $R_{\rm{K}}\ge70$).
Of the seven sources with radio detection, three of them (CTQ 0408, SDSSJ141546.24+112943.4, and SDSSJ210524.49+000407.3) are classified as radio-intermediate. The radio-loud sources from our sample are B1422+231, PKS 1937-101, PKS 2000-330, and PKS 2126-15, about 20% of the sources of this sample. We plan to carry out in a forth-coming paper a similar spectroscopic study focused on RL quasars, to supplement those  listed in Table <ref>.

§ SPECTRAL ANALYSIS

§.§ Optical range: multicomponent fitting

The multicomponent fits were performed, after the spectra were set at rest-frame, using the specfit routine from IRAF [Kriss, 1994]. This routine allows for simultaneous minimum-$\chi^2$ fit of the continuum approximated by a power-law and the spectral line components yielding FWHM, peak wavelength, and intensity of all line components. In the optical range we fit the H$\beta$ profile as well as the [OIII]$\lambda\lambda 4959,5007$ emission lines and the FeII multiplets for the 22 objects.

Our approach includes the continuum (a power law), a semi-empirical scalable FeII emission template and the emission line components to fit the H$\beta$+[OIII]$\lambda\lambda 4959,5007$ region. The FeII template used is almost identical to the one of [Boroson & Green, 1992]. The specfit routine allows for the scaling, broadening, and shifting of the FeII template to model the observed features [Marziani et al., 2003].
A sketch to illustrate the decomposition approach performed on the fittings of emission lines broad profiles is presented in Fig. <ref>. The fit of the  full profile takes into account three main components:

* Broad component (BC): this component is kept symmetric, set almost always at rest-frame, and presents a FWHM range that goes from $\gtrsim 3000$ km s$^{-1}$ for some Pop. A and $\lesssim 6000$ km s$^{-1}$ for Pop. B quasars. The profile changes depending on the quasar population, presenting a Lorentzian-like shape for Pop. A and a Gaussian-like one for Pop. B sources [Sulentic et al., 2002, Marziani et al., 2003, Zamfir et al., 2010, Cracco et al., 2016];

* Blueshifted component (BLUE):
our first assumption is to model this component by only a blue-shifted Gaussian (symmetric or skewed) profile  with FWHM and shift similar to the  semi-broad component (SBC, explained in <ref>). When the H$\beta$ profile does not correspond to the blueshifted SBC of  profile, it is included in the fitting an additional Gaussian blue-shifted component that may not belong to NLR emission (BLUE). BLUE is believed, unlike the SBC,  to be associated with emission of outflowing gas from within the BLR  [Negrete et al., 2018];

* Very broad component (VBC): it is clearly observed in Population B sources [Sulentic et al., 2017, Wolf et al., 2020]. It is always represented by a redshifted Gaussian profile and it is thought to be related with the high-ionisation virialised region closest to the continuum source [Peterson & Ferland, 1986, Snedden & Gaskell, 2007, Wang & Li, 2011]. This component can easily achieve FWHM $\gtrsim$ 10000 km s$^{-1}$.

Sketch of the approach followed for broad profile fittings.

In addition, we include a narrow component (NC) superimposed to the broad emission line profile and it is fitted as an unshifted Gaussian.

The Population classification depends on the FWHM of the full profile. Depending on the population assignment, different components are included and they assume different line shapes. An exhaustive analysis of the fittings were performed and in borderline cases (i.e., with line width close to the boundary between Pop. A and B), the final conclusion on the population of the source is based on the $\chi^2$ of the fitting (i.e., the fittings with the minimum $\chi^2$ are selected).

An approach similar to the one used for  is also followed for the [OIII]$\lambda\lambda 4959,5007$ emission line profiles. The [OIII]$\lambda\lambda 4959,5007$ full profile is assumed to be well represented by a Gaussian narrow (FWHM $\lesssim 1200$ km s$^{-1}$) component set at rest-frame or shifted to the blue and a semi-broad component (SBC, FWHM typically $\lesssim 3000$ km s$^{-1}$) that usually appears more shifted to the blue <cit.>. The NC is modelled as a Gaussian profile for the two populations and in a first approach the NC of both H$\beta$ and  share the same line width. The blueshifted contributions can be modelled by one or more Gaussian profiles and in some cases the Gaussian needs to be asymmetric towards the blue to account for the line shape, i.e., to be a skewed Gaussian. The use of a skewed Gaussian has a physical motivation, as it might be associated with bipolar outflow emission in which the receding side of the outflow is obscured. Apart from that, both [Oiii]$\lambda 4959$ and [Oiii]$\lambda 5007$ emission line profiles are assumed to have the same FWHM and shifts, and the intensity ratio between the two lines is kept fixed at 1:3 [Dimitrijević et al., 2007].

§.§ UV range: multicomponent fitting

Fits are performed for three different regions centred on SiIV$\lambda1397$+OIV]$\lambda1402$, CIV$\lambda1549$+HeII$\lambda1640$,
and the 1900 Å blend that includes the AlIII$\lambda 1860$ doublet, SiIII]$\lambda 1892$, SiII $\lambda 1816$, and CIII]$\lambda 1909$. UV fittings are presented for 15 sources. The fits were not carried out in cases where the emission lines are strongly affected by BALs. The fittings of the absorption lines are performed in sources in which the presence of these lines allows to clearly see the emission line profile  (as in the case of mini-BALs; Sulentic et al., 2006).
The UV blends are fit following the population assignments from the H$\beta$ spectral range. The only exception is SDSSJ153830.55+085517.0, where its UV spectrum cannot be fitted in agreement with its classification as Pop. B in the H$\beta$ region, as highlighted in the Appendix <ref>.

§.§.§ 1900 Å blend

In the UV region corresponding to the 1900 $\AA$ blend, the fittings are performed considering the AlIII$\lambda 1860$ doublet, SiIII]$\lambda 1892$, SiII $\lambda 1816$, and CIII]$\lambda 1909$ emission line profiles.  FeIII is especially relevant on the red side of the 1900 Å blend and its modelling has been performed using the [Vestergaard & Wilkes, 2001] empirical template, and following the same approach as for the optical FeII.

Broad line components of the 1900 Å blend  in Pop. A sources are fitted by Lorentzian profiles while in Pop. B by Gaussian functions (as is the case of  in the optical spectral range), keeping the same (or at least a comparable) FWHM to the broad component of H$\beta$.

In several Pop. A and more frequently in xA quasars, the FeIII template and the CIII]$\lambda 1909$ broad component do not reproduce well the shape of the red side of the 1900 Å blend. A better model of the CIII]$\lambda 1909$ region is achieved assuming an additional contribution mostly likely due to the FeIII line at 1914Å. The same approach was employed in [Martínez-Aldama et al., 2018].

Regarding the Pop. B sources, the  CIII]$\lambda 1909$ emission line is well represented by the same combination applied for Pop. B H$\beta$: VBC+BC+NC. The VBC FWHM is expected to be $\ge 4000$ km s$^{-1}$, and the NC FWHM $\sim 1000$ km s$^{-1}$ (there is only one source that shows a significant NC in CIII]). Differently from CIII]$\lambda 1909$, lines such as the AlIII$\lambda 1860$ doublet, SiIII]$\lambda 1892$, and SiII $\lambda 1816$ are assumed not to present a very broad component [Buendia-Rios et al., 2022]. They are  fit by only one BC.

§.§.§ CIV$\lambda1549$+HeII$\lambda1640$

In order to fit the CIV$\lambda1549$+HeII$\lambda1640$ blend and contaminant lines within it, we use the approach    followed by [Sulentic et al., 2017]. As in the previous fits, we represent Pop. A profiles of CIV$\lambda1549$ and HeII$\lambda1640$ by a broad and a blueshifted component. Pop. B are represented by the combination VBC+BC+BLUE. The broad components of CIV$\lambda1549$ and HeII$\lambda1640$ are fixed at rest-frame and the other components are left free to vary in wavelength. Nevertheless, the FWHM and shapes of HeII$\lambda1640$ BC and BLUE are restricted to be equal (or comparable) to the corresponding ones of CIV$\lambda1549$. These constraints are physically motivated since both  and  are expected to be emitted from the same regions, because of the similar ionisation potential of the parent ionic species. An additional condition is that the broad component (BC) of  and HeII$\lambda1640$ FWHM should be equal or larger to the one of , following previous works <cit.>.

§.§.§ SiIV$\lambda1397$+OIV]$\lambda1402$

For the SiIV$\lambda1397$+OIV]$\lambda1402$ emission lines region, we follow the same steps as in the CIV+HeII blend. The  SiIV$\lambda1397$+OIV]$\lambda1402$ feature profile is similar to the one of CIV$\lambda1549$, and  is therefore expected to present BC and blueshifted component similar to those of CIV$\lambda1549$. The broad component in this case is also kept at rest-frame and any other necessary component is free to change in all the parameters.

§.§ Analysis of the full profile parameters for the optical and UV regions

Apart from the multicomponent analysis, the H$\beta$ and [OIII] emission line profiles are also characterised through the parametrisation of the full profile by measuring centroids and widths at different fractional intensities (1/4, 1/2, 3/4, and 9/10), as well as asymmetry and kurtosis indexes in order to provide a quantitative description independent of the specfit modelling. In the case of H$\beta$, the full profile (H$\beta_{\textrm{full}}$) for Pop. B quasars  is represented by BC+VBC plus BLUE when detected. For Pop. A quasars, full H$\beta$ profile consists of BC plus BLUE if an additional blue component is present. For [Oiii] we consider NC and one (or more, if needed) blueshifted SBC. Full profile parameters for the UV region are provided for the  broad emission line, excluding NC.

§.§ Error estimates

Uncertainties in the multicomponent fits were estimated by running Markov Chain Monte Carlo (MCMC) simulations, following the approach described in Marziani et al., 2022 for both optical and UV spectral ranges. Observed spectra were modeled using the components employed in the best fit, with a Markov Chain to sample the domain around the minimum $\chi^2$. The dispersion in the posterior distribution of a parameter was assumed to be its 1$\sigma$ confidence interval.   For the optical range, the errors are around the order of 10% for the FWHM of the H$\beta_{\rm{BC}}$ and [OIII]$_{\rm{SBC}}$. Larger uncertainties ($\sim 30\%$) are found for the narrow components of both lines and for the blueshifted component of H$\beta$. Flux uncertainties for strong or sharp  emission lines are $\sim 10\%$, while typical errors for the continuum and FeII are $\sim 5\%$ and $\sim 15\%$  respectively, if  is reasonably strong.

For the UV, the FWHM uncertainties are between 10% and 15% and errors on intensity measurements  are usually $ \lesssim 10\%$ for the strongest emission line components.

Location of our sources through the optical plane of the 4DE1. Pop. A quasars are represented by blue circles and Pop. B by red circles. The radio-loud sources from the sample are surrounded by a circle in the plot. Grey and green regions indicate the distribution of the Main Sequence of quasars across the 4DE1 optical plane in a low-$z$ context [Marziani et al., 2018]. Spectral Types (ST) of the MS are labelled according to Sulentic et al., 2002. Blue and red squares indicate high-redshift Pop. A and Pop. B quasars from [Marziani et al., 2009], respectively. Purple-shaded areas show the luminosity-dependent boundary between Pops. A and B and the minimum FWHM value for sources with $47 \le L_{\mathrm{bol}} \le 48$ and assuming $\alpha=0.67$ [Marziani et al., 2009].

§ RESULTS

§.§ Location in the optical plane of Main Sequence

After performing the multicomponent fitting, we can locate the sample in the MS optical plane, using the FWHM(H$\beta_{\rm full}$) as well as the flux ratio of FeII$\lambda$4570 and , $R_\mathrm{\ion{Fe}{II}}$. Fig. <ref> shows the location of the sources and a comparison between our sample and low- and high-$z$ samples. The grey- and green-shaded areas in the plot indicate the location of low-redshift quasars on the MS, with the xA sources situated on the green shadow.

Our sample shows a slight displacement in the direction of increasing FWHM(H$\beta$), if compared to low-$z$ samples <cit.>. There are some Pop. A sources that present a FWHM(H$\beta_{\rm{full}}$) $\sim 5000$ km s$^{-1}$. The Pop. A/B boundary at FWHM(H$\beta$) $ =4000$ km s$^{-1}$ is reasonable when considering low redshift and, consequently, lower luminosity ranges than those of high-$z$ quasars [Sulentic et al., 2004]. However, at high luminosity there is a significant effect on the H$\beta$ profile width that may shift the boundary between Pop. A and B by more than 1000 km s$^{-1}$ [Marziani et al., 2009].
Up and bottom purple shadows in Fig. <ref> indicate, respectively, the Pop. A/B boundary and the minimum FHWM(H$\beta$) found in a $47 \leq \log L_{\rm{bol}} \leq 48$ range, representative of our sample. Both boundaries were determined following [Marziani et al., 2009].

From the 22 sources of our sample, 12 are classified as Pop. A and 10 as Pop. B quasars. We found three sources to belong to spectral type (ST) A1; six Pop. A2; three Pop. A3 (extreme A); eight to be Pop. B1; and two Pop B2. The four radio-loud objects (B1422+231, PKS 1937-101, PKS 2000-330, and PKS 2126-15) are identified in Figure <ref> by the blue and red symbols surrounded by a open circle. Three of them are classified as Pop. A and only PKS 2126-15 is a Pop. B quasar. Of the three radio-intermediate, two (SDSSJ141546.24+112943.4, ST B2; SDSSJ210524.49+000407.3,  A3) show significant  and an overall spectrum associated with high accretion rates [Ganci et al., 2019, del Olmo et al., 2021, Marziani et al., 2022]. Only CTQ 0408 is classified as B1, with an optical spectrum resembling the powerful jetted sources at low $z$. The orientation may strongly affect the classification of the sources, especially in the cases when the FWHM() is at the border line of the A/B boundary. Orientation effects could be particularly important in the case of core-dominated RL sources, as the pole-on orientation may imply a narrowing of low-ionization emission line widths  [Wills & Browne, 1986, Marziani et al., 2001, Sulentic et al., 2003, Rokaki et al., 2003, Zamfir et al., 2008, Bisogni et al., 2017].

There is just one case of a blatant disagreement between the classification deduced from the optical and UV spectra of the same source: SDSSJ153830.55+085517.0, which is optically classified as Pop. B but presents clearly Pop. A-like profiles in the UV spectrum (see <ref> and Fig. <ref> in the Appendix <ref>). In this case it was necessary to fit the optical as Pop. B and the UV as Pop. A.

[]Spectrophotometric measurements on H$\beta$.

Source     Spectral    $f_{\lambda,5100}$ $^{(a)}$     $W$(H$\beta$)     $W$([OIII])     $R_{\ion{Fe}{II}}$

Type             [Å]

(1)     (2)     (3)     (4)     (5)     (6)

6cPopulation A

SDSSJ005700.18+143737.7	   	A3	   	2.5	$\pm$	0.3	   	53	$\pm$	6	   	4.5	$\pm$	0.5	   	1.13	$\pm$	0.17

SDSSJ132012.33+142037.1	   	A1	   	1.2	$\pm$	0.1	   	74	$\pm$	9	   	19.8	$\pm$	2.4	   	0.31	$\pm$	0.05

SDSSJ135831.78+050522.8	   	A2	   	2.2	$\pm$	0.3	   	68	$\pm$	8	   	16.3	$\pm$	2.0	   	0.65	$\pm$	0.10

Q 1410+096	   	A2	   	3.0	$\pm$	0.4	   	57	$\pm$	7	   	13.7	$\pm$	1.6	   	0.65	$\pm$	0.13

B1422+231	   	A1	   	4.0	$\pm$	0.5	   	78	$\pm$	9	   	9.3	$\pm$	1.1	   	0.22	$\pm$	0.03

SDSSJ161458.33+144836.9	   	A2	   	2.3	$\pm$	0.3	   	83	$\pm$	9	   	16.8	$\pm$	2.0	   	0.52	$\pm$	0.08

PKS 1937-101	   	A1	   	7.6	$\pm$	0.9	   	62	$\pm$	7	   	13.5	$\pm$	1.6	   	0.03	$\pm$	0.01

PKS 2000-330	   	A2	   	2.8	$\pm$	0.3	   	59	$\pm$	7	   	15.1	$\pm$	1.8	   	0.62	$\pm$	0.09

SDSSJ210524.49+000407.3	   	A3	   	3.9	$\pm$	0.5		   	31	$\pm$	4	   	0.4	$\pm$	3.0	   	1.00	$\pm$	0.16

SDSSJ210831.56-063022.5	   	A3	   	1.4	$\pm$	0.2		   	44	$\pm$	6	   	4.7	$\pm$	0.6	   	1.29	$\pm$	0.19

SDSSJ212329.46-005052.9	   	A2	   	4.4	$\pm$	0.5		   	34	$\pm$	5	   	5.5	$\pm$	0.7	   	0.96	$\pm$	0.14

SDSSJ235808.54+012507.2	   	A2	   	4.7	$\pm$	0.6		   	63	$\pm$	8	   	10.7	$\pm$	1.3	   	0.98	$\pm$	0.20

6cPopulation B

HE 0001-2340	   	B1	   	1.6	$\pm$	0.2		   	77	$\pm$	9	   	10.6	$\pm$	1.3	   	0.33	$\pm$	0.05

$[\rm HB89]$ 0029+073	   	B1	   	2.4	$\pm$	0.3	   	62	$\pm$	7	   	7.8	$\pm$	0.9	   	0.18	$\pm$	0.02

CTQ 408	   	B1	   	6.9	$\pm$	0.8	   	53	$\pm$	6	   	2.5	$\pm$	4.0	   	0.49	$\pm$	0.07

H 0055-2659	   	B1	   	1.9	$\pm$	0.2	   	92	$\pm$	11	   	40.6	$\pm$	4.9	   	0.29	$\pm$	0.03

SDSSJ114358.52+052444.9	   	B2	   	1.1	$\pm$	0.1	   	82	$\pm$	10	   	5.4	$\pm$	0.6	   	0.64	$\pm$	0.10

SDSSJ115954.33+201921.1	   	B1	   	2.5	$\pm$	0.3	   	78	$\pm$	9	   	15.2	$\pm$	1.8	   	0.04	$\pm$	0.01

SDSSJ120147.90+120630.2	   	B1	   	4.3	$\pm$	0.5	   	117	$\pm$	14	   	21.0	$\pm$	2.5	   	0.24	$\pm$	0.04

SDSSJ141546.24+112943.4	   	B2	   	2.1	$\pm$	0.3	   	108	$\pm$	13	   	33.9	$\pm$	4.1	   	0.71	$\pm$	0.14

SDSSJ153830.55+085517.0	   	B1	   	1.1	$\pm$	0.1	   	94	$\pm$	11	   	5.5	$\pm$	0.7	   	0.21	$\pm$	0.03

PKS 2126-15	   	B1	   	4.8	$\pm$	0.6	   	93	$\pm$	11	   	10.0	$\pm$	1.2	   	0.47	$\pm$	0.09

$^{(a)}$ In units of $10^{-15}$ erg s$^{-1}$ cm$^{-2}$ Å$^{-1}$.

[]Results from specfit analysis on H$\beta$.

7cH$\beta$ full broad profile      15cFull broad profile (BLUE+BC+VBC)      9cNarrow profile (SBC+NC)

2-8 10-22 24-32

3cBLUE$^{(a)}$         3cBC         3cVBC                  3cSBC          3cNC

12-14 16-18 20-22 26-28 30-32

Source     FWHM     A. I.     Kurt.     c($\frac{1}{4}$)     c($\frac{1}{2}$)      c($\frac{3}{4}$)     c($\frac{9}{10}$)         $I_{\mathrm{tot}}^{(b)}$         $I/I_{\mathrm{tot}}$     FWHM     Shift         $I/I_{\mathrm{tot}}$     FWHM     Shift         $I/I_{\mathrm{tot}}$     FWHM     Shift         $I_{\mathrm{tot}}^{(c)}$         $I/I_{\mathrm{tot}}$     FWHM     Shift         $I/I_{\mathrm{tot}}$     FWHM     Shift

[km s$^{-1}$]               [km s$^{-1}$]     [km s$^{-1}$]     [km s$^{-1}$]     [km s$^{-1}$]                      [km s$^{-1}$]     [km s$^{-1}$]             [km s$^{-1}$]     [km s$^{-1}$]               [km s$^{-1}$]     [km s$^{-1}$]                     [km s$^{-1}$]     [km s$^{-1}$]             [km s$^{-1}$]     [km s$^{-1}$]

(1)     (2)     (3)     (4)     (5)     (6)     (7)     (8)        (9)         (10)     (11)      (12)         (13)     (14)     (15)         (16)     (17)      (18)         (19)        (20)      (21)     (22)         (23)     (24)     (25)

24cPopulation A

SDSSJ005700.18+143737.7	   	3830	$\pm$	342	   	-0.09	$\pm$	0.01	   	0.33	$\pm$	0.01	   	-359	$\pm$	237	   	-326	$\pm$	83	   	-137	$\pm$	107	   	-82	$\pm$	118	   	   	1.66	$\pm$	0.20	   	   	0.08	$\pm$	0.03	   	2562	$\pm$	359	   	-2154	$\pm$	548	   	   	0.92	$\pm$	0.06	   	3255	$\pm$	346	   	0	$\pm$	10	   	   	…			   	…			   	…			   	   	1.89	$\pm$	0.23	   	   	0.00			   	…			   	…			   	   	1.00	$\pm$	0.32	   	873	$\pm$	93	   	0	$\pm$	10

SDSSJ132012.33+142037.1	   	3450	$\pm$	314	   	-0.11	$\pm$	0.03	   	0.31	$\pm$	0.01	   	-476	$\pm$	323	   	-215	$\pm$	72	   	-138	$\pm$	93	   	-125	$\pm$	110	   	   	0.91	$\pm$	0.11	   	   	0.12	$\pm$	0.05	   	7519	$\pm$	1053	   	-1745	$\pm$	584	   	   	0.88	$\pm$	0.05	   	3224	$\pm$	343	   	-41	$\pm$	14	   	   	…			   	…			   	…			   	   	1.13	$\pm$	0.14	   	   	0.00			   	…			   	…			   	   	1.00	$\pm$	0.32	   	623	$\pm$	66	   	-22	$\pm$	17

SDSSJ135831.78+050522.8	   	3548	$\pm$	314	   	0.00	$\pm$	0.12	   	0.33	$\pm$	0.01	   	-1	$\pm$	297	   	0	$\pm$	60	   	0	$\pm$	97	   	0	$\pm$	120	   	   	1.58	$\pm$	0.19	   	   	0.00			   	…			   	…			   	   	0.92	$\pm$	0.06	   	3548	$\pm$	377	   	0	$\pm$	10	   	   	…			   	…			   	…			   	   	1.49	$\pm$	0.18	   	   	1.00	$\pm$	0.32	   	5497	$\pm$	770	   	-1712	$\pm$	572	   	   	0.00			   	…			   	…

Q 1410+096	   	3394	$\pm$	299	   	0.00	$\pm$	0.08	   	0.33	$\pm$	0.01	   	54	$\pm$	279	   	54	$\pm$	58	   	54	$\pm$	92	   	54	$\pm$	112	   	   	1.79	$\pm$	0.21	   	   	0.00			   	…			   	…			   	   	1.00	$\pm$	0.06	   	3394	$\pm$	361	   	54	$\pm$	58	   	   	…			   	…			   	…			   	   	0.37	$\pm$	0.04	   	   	1.00	$\pm$	0.32	   	4581	$\pm$	320	   	-3144	$\pm$	1051	   	   	0.00			   	…			   	…

B1422+231	   	5136	$\pm$	452	   	0.00	$\pm$	0.06	   	0.33	$\pm$	0.01	   	-1	$\pm$	422	   	-1	$\pm$	89	   	0	$\pm$	139	   	0	$\pm$	169	   	   	3.20	$\pm$	0.38	   	   	0.00			   	…			   	…			   	   	1.00	$\pm$	0.06	   	5135	$\pm$	546	   	0	$\pm$	10	   	   	…			   	…			   	…			   	   	0.57	$\pm$	0.07	   	   	0.00			   	…			   	…			   	   	1.00	$\pm$	0.32	   	1113	$\pm$	118	   	0	$\pm$	10

SDSSJ161458.33+144836.9	   	3885	$\pm$	349	   	-0.06	$\pm$	0.11	   	0.33	$\pm$	0.01	   	-241	$\pm$	327	   	-98	$\pm$	73	   	-51	$\pm$	106	   	-38	$\pm$	130	   	   	1.89	$\pm$	0.21	   	   	0.09	$\pm$	0.03	   	7224	$\pm$	506	   	-1713	$\pm$	571	   	   	0.91	$\pm$	0.06	   	3721	$\pm$	396	   	0	$\pm$	10	   	   	…			   	…			   	…			   	   	0.54	$\pm$	0.06	   	   	0.70	$\pm$	0.25	   	2445	$\pm$	170	   	-1709	$\pm$	569	   	   	0.30	$\pm$	0.09	   	439	$\pm$	47	   	0	$\pm$	10

PKS 1937-101	   	5298	$\pm$	466	   	0.00	$\pm$	0.07	   	0.33	$\pm$	0.01	   	56	$\pm$	434	   	56	$\pm$	92	   	56	$\pm$	144	   	56	$\pm$	174	   	   	5.15	$\pm$	0.62	   	   	0.00			   	…			   	…			   	   	1.00	$\pm$	0.06	   	5296	$\pm$	563	   	56	$\pm$	92	   	   	…			   	…			   	…			   	   	1.57	$\pm$	0.19	   	   	0.29	$\pm$	0.09	   	2618	$\pm$	183	   	-555	$\pm$	183	   	   	0.71	$\pm$	0.22	   	852	$\pm$	91	   	-47	$\pm$	-77

PKS 2000-330	   	3230	$\pm$	294	   	-0.06	$\pm$	0.07	   	0.32	$\pm$	0.01	   	-175	$\pm$	306	   	-30	$\pm$	61	   	1	$\pm$	89	   	9	$\pm$	108	   	   	1.92	$\pm$	0.22	   	   	0.05	$\pm$	0.01	   	5499	$\pm$	385	   	-3127	$\pm$	1031	   	   	0.95	$\pm$	0.06	   	3138	$\pm$	334	   	28	$\pm$	54	   	   	…			   	…			   	…			   	   	2.31	$\pm$	0.28	   	   	0.36	$\pm$	0.11	   	1499	$\pm$	105	   	-599	$\pm$	197	   	   	0.63	$\pm$	0.20	   	1082	$\pm$	115	   	-46	$\pm$	-89

SDSSJ210524.49+000407.3	   	5026	$\pm$	446	   	0.00	$\pm$	0.06	   	0.33	$\pm$	0.01	   	-1	$\pm$	420	   	0	$\pm$	85	   	0	$\pm$	137	   	0	$\pm$	169	   	   	1.28	$\pm$	0.15	   	   	0.00			   	…			   	…			   	   	1.00	$\pm$	0.06	   	5026	$\pm$	534	   	0	$\pm$	10	   	   	…			   	…			   	…			   	   	0.40	$\pm$	0.05	   	   	0.00			   	…			   	…			   	   	1.00	$\pm$	0.32	   	1407	$\pm$	150	   	0	$\pm$	10

SDSSJ210831.56-063022.5	   	4545	$\pm$	200	   	0.00	$\pm$	0.04	   	0.33	$\pm$	0.01	   	93	$\pm$	372	   	93	$\pm$	79	   	93	$\pm$	124	    93	$\pm$	149	   	   	0.60	$\pm$	0.08	   	   	0.00			   	…			   	…			   	   	0.91	$\pm$	0.06	   	4543	$\pm$	483	   	93	$\pm$	16	   	   	…			   	…			   	…			   	   	0.68	$\pm$	0.08	   	   	0.89	$\pm$	0.28	   	2597	$\pm$	364	   	-2018	$\pm$	347	   	   	0.11	$\pm$	0.03	   	1403	$\pm$	149	   	0	$\pm$	10

SDSSJ212329.46-005052.9	   	4165	$\pm$	366	   	0.00	$\pm$	0.03	   	0.33	$\pm$	0.01	   	-1	$\pm$	342	   	-1	$\pm$	72	   	0	$\pm$	200	   	-1	$\pm$	231	   	   	1.60	$\pm$	0.22	   	   	0.00			   	…			   	…			   	   	0.89	$\pm$	0.05	   	4164	$\pm$	443	   	0	$\pm$	10	   	   	…			   	…			   	…			   	   	2.40	$\pm$	0.29	   	   	0.86	$\pm$	0.27	   	4969	$\pm$	696	   	-1844	$\pm$	323	   	   	0.14	$\pm$	0.04	   	1188	$\pm$	126	   	0	$\pm$	10

SDSSJ235808.54+012507.2	   	4098	$\pm$	360	   	0.03	$\pm$	0.06	   	0.35	$\pm$	0.01	   	0	$\pm$	336	   	0	$\pm$	70	   	0	$\pm$	111	   	-1	$\pm$	136	   	   	2.88	$\pm$	0.35	   	   	0.00			   	…			   	…			   	   	1.00	$\pm$	0.06	   	4098	$\pm$	436	   	0	$\pm$	10	   	   	…			   	…			   	…			   	   	3.76	$\pm$	0.45	   	   	0.38	$\pm$	0.12	   	2463	$\pm$	172	   	-1030	$\pm$	340	   	   	0.61	$\pm$	0.19	   	954	$\pm$	101	   	0	$\pm$	10

Median     3991 $\pm$ 1141     0.00 $\pm$ 0.06     0.33 $\pm$ 0.01     -1 $\pm$ 205     -0.5 $\pm$ 61     0 $\pm$ 27     0 $\pm$ 51        	1.72 $\pm$ 0.65    	    0.08 $\pm$ 0.02    	6362 $\pm$ 2533      -1949 $\pm$ 660        	0.93 $\pm$ 0.09     3909 $\pm$ 1305     0$\pm$ 34         …     …     …         1.31 $\pm$ 1.43         0.78 $\pm$ 0.54     2607 $\pm$ 2219     -1710 $\pm$ 965         0.67 $\pm$ 0.62     1018 $\pm$ 312     0 $\pm$ 16

24cPopulation B

HE 0001-2340	   	6632	$\pm$	1065	   	0.16	$\pm$	0.22	   	0.37	$\pm$	0.01	   	1757	$\pm$	873	   	1134	$\pm$	153	   	960	$\pm$	354	   	909	$\pm$	471	   	   	1.30	$\pm$	0.16	   	   	0.00			   	…			   	…			   	   	0.42	$\pm$	0.06	   	5063	$\pm$	366	   	681	$\pm$	92	   	   	0.58	$\pm$	0.06	   	10982	$\pm$	1955	   	2538	$\pm$	342	   	   	0.33	$\pm$	0.04	   	   	0.34	$\pm$	0.11	   	3772	$\pm$	264	   	-414	$\pm$	136	   	   	0.65	$\pm$	0.21	   	1067	$\pm$	77	   	0	$\pm$	10$^{(d)}$

$[\rm HB89]$ 0029+073	   	6347	$\pm$	1085	   	0.18	$\pm$	0.05	   	0.37	$\pm$	0.01	   	932	$\pm$	757	   	292	$\pm$	138	   	51	$\pm$	339	   	-19	$\pm$	442	   	   	1.54	$\pm$	0.18	   	   	0.07	$\pm$	0.01	   	4995	$\pm$	837	   	-1216	$\pm$	575	   	   	0.33	$\pm$	0.05	   	4508	$\pm$	326	   	-310	$\pm$	147	   	   	0.60	$\pm$	0.06	   	9609	$\pm$	1710	   	1430	$\pm$	193	   	   	1.54	$\pm$	0.18	   	   	0.00			   	…			   	…			   	   	1.00	$\pm$	0.32	   	1024	$\pm$	74	   	0	$\pm$	10

CTQ 408	   	7301	$\pm$	1081	   	0.10	$\pm$	0.09	   	0.40	$\pm$	0.02	   	724	$\pm$	910	   	306	$\pm$	179	   	197	$\pm$	390	   	164	$\pm$	528	   	   	3.90	$\pm$	0.47	   	   	0.00			   	…			   	…			   	   	0.52	$\pm$	0.08	   	6050	$\pm$	437	   	0	$\pm$	10	   	   	0.48	$\pm$	0.05	   	13243	$\pm$	2357	   	1963	$\pm$	264	   	   	2.54	$\pm$	0.30	   	   	0.00			   	…			   	…			   	   	1.00	$\pm$	0.32	   	1500	$\pm$	108	   	0	$\pm$	10

H 0055-2659	   	5342	$\pm$	925	   	0.36	$\pm$	0.13	   	0.30	$\pm$	0.03	   	2249	$\pm$	1085	   	580	$\pm$	101	   	380	$\pm$	283	   	329	$\pm$	377	   	   	1.85	$\pm$	0.22	   	   	0.00			   	…			   	…			   	   	0.27	$\pm$	0.04	   	4609	$\pm$	333	   	-224	$\pm$	39	   	   	0.73	$\pm$	0.07	   	13355	$\pm$	2377	   	2527	$\pm$	340	   	   	0.82	$\pm$	0.10	   	   	0.00			   	…			   	…			   	   	1.00	$\pm$	0.32	   	1500	$\pm$	108	   	0	$\pm$	10

SDSSJ114358.52+052444.9	   	5999	$\pm$	942	   	0.24	$\pm$	0.15	   	0.34	$\pm$	0.05	   	1485	$\pm$	1408	   	354	$\pm$	133	   	210	$\pm$	319	   	170	$\pm$	431	   	   	1.00	$\pm$	0.12	   	   	0.00			   	…			   	…			   	   	0.52	$\pm$	0.08	   	5007	$\pm$	362	   	0	$\pm$	10	   	   	0.48	$\pm$	0.05	   	13341	$\pm$	2375	   	4095	$\pm$	552	   	   	0.34	$\pm$	0.04	   	   	0.47	$\pm$	0.15	   	1830	$\pm$	128	   	-1277	$\pm$	421	   	   	0.53	$\pm$	0.17	   	1304	$\pm$	94	   	0	$\pm$	10$^{(d)}$

SDSSJ115954.33+201921.1	   	8006	$\pm$	1659	   	0.29	$\pm$	0.10	   	0.33	$\pm$	0.01	   	2389	$\pm$	1025	   	950	$\pm$	133	   	469	$\pm$	422	   	359	$\pm$	536	   	   	2.05	$\pm$	0.25	   	   	0.00			   	…			   	…			   	   	0.36	$\pm$	0.05	   	5458	$\pm$	395	   	-35	$\pm$	15	   	   	0.64	$\pm$	0.06	   	12924	$\pm$	2300	   	3287	$\pm$	443	   	   	0.42	$\pm$	0.05	   	   	0.72	$\pm$	0.23	   	2660	$\pm$	186	   	-1215	$\pm$	401	   	   	0.27	$\pm$	0.08	   	995	$\pm$	72	   	-101	$\pm$	14

SDSSJ120147.90+120630.2	   	7995	$\pm$	1748	   	0.28	$\pm$	0.11	   	0.33	$\pm$	0.01	   	2331	$\pm$	947	   	1124	$\pm$	140	   	540	$\pm$	421	   	414	$\pm$	519	   	   	4.31	$\pm$	0.52	   	   	0.00			   	…			   	…			   	   	0.30	$\pm$	0.04	   	4986	$\pm$	360	   	9	$\pm$	10	   	   	0.70	$\pm$	0.07	   	12190	$\pm$	2170	   	2850	$\pm$	384	   	   	6.33	$\pm$	0.76	   	   	0.05	$\pm$	0.01	   	1879	$\pm$	131	   	-246	$\pm$	81	   	   	0.95	$\pm$	0.30	   	1879	$\pm$	136	   	-1	$\pm$	10

SDSSJ141546.24+112943.4	   	7253	$\pm$	1237	   	0.23	$\pm$	0.11	   	0.36	$\pm$	0.02	   	1769	$\pm$	952	   	736	$\pm$	145	   	447	$\pm$	387	   	367	$\pm$	510	   	   	1.59	$\pm$	0.19	   	   	0.00			   	…			   	…			   	   	0.45	$\pm$	0.07	   	5544	$\pm$	401	   	14	$\pm$	13	   	   	0.55	$\pm$	0.05	   	11523	$\pm$	2051	   	3144	$\pm$	423	   	   	1.31	$\pm$	0.16	   	   	0.29	$\pm$	0.09	   	1000	$\pm$	70	   	-784	$\pm$	258	   	   	0.71	$\pm$	0.22	   	1162	$\pm$	84	   	14	$\pm$	13

SDSSJ153830.55+085517.0	   	7816	$\pm$	1354	   	0.25	$\pm$	0.11	   	0.35	$\pm$	0.02	   	2090	$\pm$	1081	   	800	$\pm$	152	   	478	$\pm$	415	   	390	$\pm$	548	   	   	1.16	$\pm$	0.14	   	   	0.00			   	…			   	…			   	   	0.47	$\pm$	0.07	   	6038	$\pm$	437	   	9	$\pm$	12	   	   	0.53	$\pm$	0.05	   	12642	$\pm$	2250	   	3869	$\pm$	521	   	   	0.50	$\pm$	0.06	   	   	0.00			   	…			   	…			   	   	1.00	$\pm$	0.32	   	1000	$\pm$	72	   	-1	$\pm$	10

PKS 2126-15$^{(e)}$	   	5018	$\pm$	648	   	0.50	$\pm$	0.09	   	0.22	$\pm$	0.01	   	2104	$\pm$	414	   	81	$\pm$	51	   	-303	$\pm$	168	   	-713	$\pm$	90	   	   	4.28	$\pm$	0.51	   	   	0.09	$\pm$	0.02	   	4662 $\pm$ 781	   	-4717 $\pm$ 2970		   	   	0.35	$\pm$	0.05	   	4074	$\pm$	295	   	-589	$\pm$	371	   	   	0.56	$\pm$	0.05	   	9992	$\pm$	1779	   	3585	$\pm$	483	   	   	3.34	$\pm$	0.40	   	   	0.17	$\pm$	0.05	   	1345	$\pm$	94	   	-426	$\pm$	140	   	   	0.83	$\pm$	0.26	   	922	$\pm$	67	   	0	$\pm$	10

Median     6942 $\pm$ 1601     0.24 $\pm$ 0.09     0.34 $\pm$ 0.03      1929 $\pm$ 659     658 $\pm$ 594     413 $\pm$ 275     344 $\pm$ 218         1.72 $\pm$ 2.07         0.08 $\pm$ 0.01     4828 $\pm$ 166     -2966 $\pm$ 1750         0.39 $\pm$ 0.13     5035 $\pm$ 819     0 $\pm$ 186         0.57 $\pm$ 0.09     12416 $\pm$ 2046     2997 $\pm$ 980         1.06 $\pm$ 1.85         0.31 $\pm$ 0.23     1854 $\pm$ 998      -605 $\pm$ 690         0.89 $\pm$ 0.33     1114 $\pm$ 445     0 $\pm$ 1

$^{(a)}$ In these columns, we report additional blueshifted components that were included in the H$\beta$ profile.
$^{(b)}$ In units of $10^{-13}$ erg s$^{-1}$ cm$^{-2}$.
$^{(c)}$ In units of $10^{-14}$ erg s$^{-1}$ cm$^{-2}$.
$^{(d)}$ There is an additional contribution due to small blueshifted components associated with narrow line emission.
$^{(e)}$ Full profile centroid velocities and the presence of a BLUE H$\beta$ component in this case are affected by the location of the continuum.

§.§ Optical

§.§.§ H$\beta$

Appendix <ref> shows the full VLT-ISAAC optical spectra and their respective H$\beta$+[OIII]$\lambda\lambda 4959,5007$ fittings. Spectrophotometric measurements on H$\beta$  are presented in Table <ref>. The ST of each source is listed in Col. 2; the specific continuum flux at 5100Å (in rest-frame) is in Col. 3; equivalent width (EW) of the  and  full profiles in Cols. 4 and 5, respectively; and the FeII prominence parameter ($R_{\ion{Fe}{ii}}$) is listed in Col. 7.

Table <ref> reports  measurements on the H$\beta$ profile. First we  present the parameters obtained through the analysis of the H$\beta$ full broad profile, including FWHM(H$\beta_{\rm{full}}$) (Col. 2), asymmetry index (Col. 3), kurtosis (Col. 4), and the centroid velocity shifts at $\frac{1}{4}$, $\frac{1}{2}$, $\frac{3}{4}$, and $\frac{9}{10}$ fractional intensity (Cols. 5, 6, 7, and 8, respectively). In Col. 9 we list the full H$\beta$ line flux (i.e., the flux for all broad line components, BC and VBC and BLUE whenever appropriate). For each broad component isolated with the specfit analysis we report, from Col. 10 to 18, flux normalised by the total flux ($I/I_{\mathrm{tot}}$), FWHM, and velocity shift. Col. 19 shows the total flux of the narrow profile (SBC+NC) and from Cols. 20 to 25 we report $I/I_{\mathrm{tot}}$, FWHM, and shift for these components. Additionally, we provide, in the last row of Pop. A and B respectively, the  median values of the measurements, together with the interquartile range.

The centroid velocities are close to the rest-frame wavelength for the majority of Pop. A and only two of the Pop. A quasars present $c$(1/2) strongly shifted towards the blue with an averaged value of $\approx -271$ km s$^{-1}$. These sources are SDSSJ005700-18+14737.7 (ST A3) and  SDSSJ132012.33+142037.1 (A1), both of them presenting a clear blueshifted contribution in H$\beta$ profile. In the case of Pop. B quasars, the centroid velocities are significantly shifted towards the red wing of the profile in every fractional intensity for the majority of the sources, with an averaged $c$(1/2) value of $\sim 640$ . Even higher values are found for $c$(1/4): Pop. B present an averaged value of $\approx$1780 km s$^{-1}$ while Pop. A have $c$(1/4) $\approx$ -149 .

Pop. B sources show FWHM(H$\beta_{\rm{full}}$) values much larger than those of Pop. A, usually $\sim 6000$ km s$^{-1}$. This difference is a direct consequence of the definition of Pop. A and B.  The Pop. B asymmetry index is positive and very significantly different from 0, since the contribution of the VBC  – that  reaches FWHM values $\gtrsim$ 10000 km s$^{-1}$ – in all cases  represents  $\gtrsim 50$% of the full emission line profile. In other words, differently from Pop. A sources (in which only a symmetric BC is enough to represent the full profile in the majority of the cases), a second redshifted component is always needed to reproduce the strong red wing of the observed  profile.

Left panel: FWHM(H$\beta_{\rm BC}$) vs. FWHM of the full H$\beta$ profile. Central panel: velocity centroid at 1/2 intensity $c$(1/2) vs. FWHM(H$\beta_{\rm full}$). Right panel: velocity centroid at 1/4 flux intensity $c$(1/4) vs. FWHM(H$\beta_{\rm full}$). Symbols surrounded by open circles show the radio-loud sources and filled circles represent the radio-quiet from the sample. Red line represent the linear regression performed for Pop. B. Horizontal dashed lines in the central and right panels indicate $c$(1/4) $=0$ and $c$(1/2) $=0$ for , respectively. Purple vertical dashed lines shows the boundary between Pop. A and Pop. B. The many MS spectral type (ST) are represented in different colours: A1 ($\bullet$); A2 ($\bullet$); A3 ($\bullet$); B1 ($\bullet$); and B2 ($\bullet$).

Semi-broad  blueshifts could be mainly associated with the  SBC. However in some cases an additional BLUE H$\beta$ component is needed (see Table <ref>). PKS 2126-15  presents a huge BLUE blueshift  of $\approx -4700$ km s$^{-1}$, associated with a boxy termination of the H$\beta$ blue wing. A second peculiarity of this source is that the  BC is significantly shifted to the blue, down to half maximum, at variance with all other Pop. B sources.

The  NC is weak especially in Pop. A ($\lesssim 0.02$ of the  line flux) although it is  observed in all cases save two Pop. A2 sources (SDSSJ132012.33+142037.1 and Q 1410+096). In Pop. B, the narrow component is somewhat stronger but always $\lesssim 0.05$ of the line flux. Given its weakness,  the NC is therefore not significantly affecting the flux of any broad component measured in this paper.

Relation between FWHM(H$\beta_{\rm{full}}$) and FWHM(H$\beta_{\rm{BC}}$).   This work confirms previous studies <cit.> that showed that the full  profile of Pop. A can be accounted for mostly by the BC, and that a redshifted VBC seems to be absent in Population A but present in Pop. B sources: Table <ref>  lists  centroid and asymmetry index values for Pop. B sources of $1000 \lesssim c(\frac{1}{4}) \lesssim 2000$  and $\approx 0.2$, respectively. For Pop. A these values are $\lesssim 0$  and 0.

The left plot of Fig. <ref> shows the relation between the FWHM of the BC and the FWHM of the full profile of H$\beta$ for the two populations. Pop. A and Pop. B sources  follow different trends for the ratio $\xi(\rm H\beta)=$ FWHM(H$\beta_{\rm BC}$)/FWHM(H$\beta_{\rm full}$). For Pop. A quasars, we obtain $\xi(\rm H\beta)= 1.00$ for all sources but four (SDSSJ005700.18+143737.7, SDSSJ132012.33+142037.1, SDSSJ161458.33+144836.9, and PKS2000-330, with $\xi(\rm H\beta)\approx 0.9$ due to the presence of a blueshifted component). The $\xi(\rm H\beta)$ ratio for Pop. B is only $\approx$ 0.76, indicating that the Pop. B  full profile is less representative of the BC than the Pop. A sources. Similar results were also shown by [Marziani et al., 2013]: they obtain $\xi(\rm H\beta)=1.00$ for Pop. A and $\sim 0.78$ for Pop. B quasars.
In our sample Pop. B sources  usually present a very strong and wide  VBC component that accounts for $\approx 0.57$ of the profile, with a mean FWHM of 11240 km s$^{-1}$.  Meanwhile, as mentioned, the Pop. A sources in general are well represented by only a BC.
This also seems to be true for the radio-loud Pop. A sources from the sample.

Clear distinctions between Pop. A and Pop. B are also seen in the center and left panels of Fig. <ref>, which present the $c$(1/2) and $c$(1/4) vs. FWHM(H$\beta_{\rm{full}}$) relations, respectively. Pop. A sources show in general no shift, within the uncertainties, or a negative value of velocity centroids in the case of the 4 sources with a BLUE component (with average centroid values at 1/2 and 1/4 of -167 and -312 km s$^{-1}$, respectively). On the other hand, Pop. B sources always present positive velocities for $c$(1/2) and $c$(1/4), with a mean value of $658$ and $1929$ km s$^{-1}$, respectively, as a consequence of a very strong VBC. The VBC individually has a median velocity shift of $\sim3000$ km s$^{-1}$, in a range from $-1500$ to $4000$ km s$^{-1}$. These results are in complete agreement with previous results <cit.>.

[]Measurements on the [OIII]$\lambda5007$ full line profile.

5c[OIII]$\lambda5007$ full profile         3cSBC         3cNC

2-6 8-10 12-14

Source      FWHM      A. I.     Kurtosis     $c$(1/2)     $c$(9/10)         $I/I_{\mathrm{tot}}$     FWHM     Shift         $I/I_{\mathrm{tot}}$     FWHM     Shift

[km s$^{-1}$]                 [km s$^{-1}$]     [km s$^{-1}$]              [km s$^{-1}$]     [km s$^{-1}$]               [km s$^{-1}$]     [km s$^{-1}$]

(1)     (2)     (3)     (4)      (5)     (6)         (7)     (8)     (9)         (10)     (11)     (12)

14cPopulation A

SDSSJ005700.18+143737.7$^{(a)}$	   	764::		   	-0.01::		   	0.45::		   	-89::		   	-88::		   	   	0.27::		   	1214::		   	-1856::		   	   	0.732::		   	761::		   	-87::

SDSSJ132012.33+142037.1	   	2124	$\pm$	147	   	-0.54	$\pm$	0.01	   	0.23	$\pm$	0.01	   	-770	$\pm$	62	   	-221	$\pm$	36	   	   	0.64	$\pm$	0.06	   	2275	$\pm$	235	   	-1429	$\pm$	115	   	   	0.357	$\pm$	0.114	   	895	$\pm$	95	   	-149	$\pm$	22

SDSSJ135831.78+050522.8	   	4320	$\pm$	297	   	-0.43	$\pm$	0.05	   	0.19	$\pm$	0.10	   	-1895	$\pm$	91	   	-630	$\pm$	59	   	   	0.90	$\pm$	0.08	   	5422	$\pm$	561	   	-2080	$\pm$	100	   	   	0.096	$\pm$	0.031	   	1000	$\pm$	106	   	-534	$\pm$	80

Q 1410+096	   	3363	$\pm$	283	   	-0.52	$\pm$	0.01	   	0.28	$\pm$	0.01	   	-1404	$\pm$	107	   	-656	$\pm$	72	   	   	0.73	$\pm$	0.07	   	5573	$\pm$	577	   	-1255	$\pm$	96	   	   	0.267	$\pm$	0.085	   	1379	$\pm$	147	   	-260	$\pm$	39

B1422+231	   	1535	$\pm$	99	   	-0.18	$\pm$	0.01	   	0.43	$\pm$	0.01	   	-217	$\pm$	26	   	-88	$\pm$	47	   	   	0.32	$\pm$	0.03	   	1128	$\pm$	117	   	-850	$\pm$	102	   	   	0.680	$\pm$	0.218	   	1117	$\pm$	119	   	27	$\pm$	4

SDSSJ161458.33+144836.9	   	2616	$\pm$	160	   	-0.49	$\pm$	0.01	   	0.28	$\pm$	0.02	   	-1452	$\pm$	54	   	-800	$\pm$	50	   	   	0.75	$\pm$	0.07	   	2759	$\pm$	286	   	-1875	$\pm$	70	   	   	0.245	$\pm$	0.078	   	1006	$\pm$	107	   	-667	$\pm$	100

PKS 1937-101	   	1046	$\pm$	79	   	-0.15	$\pm$	0.09	   	0.35	$\pm$	0.02	   	-155	$\pm$	17	   	-135	$\pm$	31	   	   	0.57	$\pm$	0.05	   	2657	$\pm$	275	   	-484	$\pm$	53	   	   	0.432	$\pm$	0.138	   	832	$\pm$	88	   	-120	$\pm$	18

PKS 2000-330	   	1314	$\pm$	89	   	-0.13	$\pm$	0.01	   	0.42	$\pm$	0.01	   	-425	$\pm$	22	   	-371	$\pm$	41	   	   	0.42	$\pm$	0.04	   	1500	$\pm$	155	   	-827	$\pm$	43	   	   	0.578	$\pm$	0.185	   	1082	$\pm$	115	   	-263	$\pm$	39

SDSSJ210524.49+000407.3	   	1365::		   	0.00::		   	0.45::		   	201::		   	202::		   	   	1.00::		   	1361::		   	203::		   	   	0.000		   	…			   	…

SDSSJ210831.56-063022.5	   	3665::	   	0.00::		   	0.46::		   	-1243::		   	-1242::		   	   	1.00::		   	3679::		   	-1244::		   	   	0.000	   	…	   	…

SDSSJ212329.46-005052.9	   	3656	$\pm$	247	   	-0.04	$\pm$	0.04	   	0.39	$\pm$	0.02	   	-2885	$\pm$	58	   	-2584	$\pm$	119	   	   	0.88	$\pm$	0.08	   	4719	$\pm$	488	   	-2376	$\pm$	48	   	   	0.115::		   	2043::		   	174::

SDSSJ235808.54+012507.2	   	1870	$\pm$	224	   	0.00	$\pm$	0.03	   	0.46	$\pm$	0.01	   	-943	$\pm$	78	   	-942	$\pm$	49	   	   	1.00	$\pm$	0.09	   	2464	$\pm$	255	   	-1053	$\pm$	87	   	   	0.000	   	…			   	…

Median     1997 $\pm$ 2045     -0.14 $\pm$ 0.42     0.40 $\pm$ 0.17     -856 $\pm$ 1214     -500 $\pm$ 707         0.68 $\pm$ 0.49      2560 $\pm$ 2032     -1249 $\pm$ 1016         0.312 $\pm$ 0.493     1082 $\pm$ 427     -120 $\pm$ 288

14cPopulation B

HE 0001-2340	   	1029	$\pm$	145	   	-0.07	$\pm$	0.10	   	0.40	$\pm$	0.02	   	-24	$\pm$	30	   	-12	$\pm$	64	   	   	0.43	$\pm$	0.03	   	2768	$\pm$	90	   	-443	$\pm$	554	   	   	0.565	$\pm$	0.202	   	894	$\pm$	65	   	-1	$\pm$	10

$[\rm HB89]$ 0029+073	   	1866	$\pm$	271	   	-0.47	$\pm$	0.01	   	0.38	$\pm$	0.01	   	-922	$\pm$	97	   	-562	$\pm$	114	   	   	1.00	$\pm$	0.06	   	3431	$\pm$	168	   	-397	$\pm$	42	   	   	0.000	   	…			   	…

CTQ 408	   	1497	$\pm$	190	   	0.00	$\pm$	0.01	   	0.46	$\pm$	0.01	   	-524	$\pm$	37	   	-524	$\pm$	97	   	   	1.00	$\pm$	0.09	   	1500	$\pm$	401	   	-524	$\pm$	37	   	   	0.000	   	…			   	…

H 0055-2659	   	1405	$\pm$	325	   	-0.47	$\pm$	0.06	   	0.25	$\pm$	0.01	   	-198	$\pm$	103	   	-91	$\pm$	81	   	   	0.50	$\pm$	0.07	   	3204	$\pm$	412	   	-599	$\pm$	312	   	   	0.496	$\pm$	0.177	   	912	$\pm$	66	   	69	$\pm$	10

SDSSJ114358.52+052444.9	   	2577	$\pm$	251	   	0.05	$\pm$	0.03	   	0.54	$\pm$	0.02	   	-968	$\pm$	52	   	-1079	$\pm$	186	   	   	0.78	$\pm$	0.03	   	1982	$\pm$	83	   	-1295	$\pm$	70	   	   	0.220	$\pm$	0.078	   	1304	$\pm$	94	   	-1	$\pm$	10

SDSSJ115954.33+201921.1	   	1233	$\pm$	186	   	-0.20	$\pm$	0.10	   	0.37	$\pm$	0.03	   	-347	$\pm$	46	   	-302	$\pm$	76	   	   	0.55	$\pm$	0.07	   	2684	$\pm$	204	   	-499	$\pm$	66	   	   	0.448	$\pm$	0.160	   	995	$\pm$	72	   	-261	$\pm$	39

SDSSJ120147.90+120630.2	   	2584	$\pm$	200	   	-0.10	$\pm$	0.01	   	0.61	$\pm$	0.01	   	-594	$\pm$	49	   	-504	$\pm$	126	   	   	0.72	$\pm$	0.05	   	1879	$\pm$	196	   	-978	$\pm$	81	   	   	0.280	$\pm$	0.100	   	1129	$\pm$	82	   	244	$\pm$	37

SDSSJ141546.24+112943.4	   	1193	$\pm$	204	   	-0.37	$\pm$	0.01	   	0.38	$\pm$	0.01	   	-116	$\pm$	70	   	55	$\pm$	75	   	   	0.47	$\pm$	0.04	   	1499	$\pm$	111	   	-415	$\pm$	250	   	   	0.526	$\pm$	0.188	   	700	$\pm$	51	   	151	$\pm$	23

SDSSJ153830.55+085517.0	   	1520	$\pm$	192	   	0.00	$\pm$	0.01	   	0.46	$\pm$	0.01	   	-545	$\pm$	38	   	-545	$\pm$	97	   	   	1.00	$\pm$	0.09	   	1523	$\pm$	101	   	-545	$\pm$	38	   	   	0.000	   	…			   	…

PKS 2126-15	   	1212	$\pm$	167	   	-0.22	$\pm$	0.03	   	0.41	$\pm$	0.01	   	-441	$\pm$	44	   	-355	$\pm$	75	   	   	0.30	$\pm$	0.09	   	1332	$\pm$	272	   	-988	$\pm$	99	   	   	0.702	$\pm$	0.250	   	937	$\pm$	68	   	-285	$\pm$	43

Median     1451 $\pm$ 562     -0.15 $\pm$ 0.31     0.40 $\pm$ 0.08     -482 $\pm$ 346     -429 $\pm$ 396         0.52 $\pm$ 0.32     1930 $\pm$ 1241     -534 $\pm$ 426         0.364 $\pm$ 0.463     937 $\pm$ 159     -1 $\pm$ 241

$^{a}$ [Oiii]$\lambda$5007 location is not clear for this source since it is placed at the red end of the observed spectrum. In this case, the measurements were performed with [Oiii]$\lambda$4959.

§.§.§ [OIII]$\lambda\lambda 4959,5007$

High-ionisation lines like  are seen as one of the main detectors of outflowing gas in radio-quiet sources [Zamanov et al., 2002, Komossa et al., 2008, Zhang et al., 2011, Marziani et al., 2016].  In the case of radio-loud sources, narrow-line outflowing gas has been associated with jets through the blueshifted line components [Capetti et al., 1996, Axon et al., 2000, Bicknell, 2002, Kauffmann et al., 2008, Best & Heckman, 2012, Reynaldi & Feinstein, 2013, Jarvis et al., 2019, Berton & Järvelä, 2021].  Outflows are also  detected in . Usually, the blueshifted components on the H$\beta$ profile  are related to those found for the  lines  [Carniani et al., 2015, Cresci et al., 2015, Brusa et al., 2015, Marziani et al., 2022].
Results obtained for [Oiii]$\lambda 5007$ full profile and individual components are reported in Table <ref>. We present FWHM (Col. 2), asymmetry (Col. 3), kurtosis (Col. 4), and the centroid velocities at 1/2 and 9/10 intensities (Cols. 5 and 6, respectively) for the full profile.  Relative intensities, FWHM, and shifts are reported for the  [Oiii]$\lambda 5007$ blueshifted components (Cols. 7 to 9) and for the narrow components (Cols. 10 to 12) of each quasar. It is difficult to distinguish the relative contribution of the two components in the majority of the cases. One of the main reasons for this is that in many sources the full [Oiii]$\lambda 5007$ emission is shifted to the blue, implying a shift of [Oiii]$\lambda 5007$ NC with respect to the rest-frame.  Some sources like SDSSJ135831.78+050522.8 and SDSSJ161458.33+144836.9 present a NC strongly shifted to the blue, reaching shifts of $\approx -530$ and $-670$ km s$^{-1}$ respectively, comparable to the shifts found for the semi-broad component (see e.g.  Figs. <ref> and <ref> in the Appendix <ref>).This is consistent with outflowing gas dominating the  luminosity in luminous quasars [Shen & Ho, 2014, Bischetti et al., 2017, Zakamska et al., 2016].

The remarkable feature of the  profiles is  a very intense and blueshifted SBC, such as the one of SDSSJ135831.78+050522.8 (Fig. <ref>), which presents a blueshifted SBC that accounts for the full  profile with a FWHM $\approx 5422$ km s$^{-1}$ and a shift of $\approx -2080$ km s$^{-1}$. In this case, the blueshifted SBC corresponds to 90% of the full profile and can be interpreted as a strong indicative of outflowing gas. SDSSJ135831.78+050522.8, along with Q 1410+096 (Fig. <ref> in the Appendix <ref>) which shows a very similar profile, requires a strong and broad  to account for the flux on the red side of . In our high luminosity sample, for 15/22 objects ($\sim$ 70%) the blueshifted SBC accounts for more than 50% of the total intensity of the  profile. In fact,  in 6 of these sources, the  consists of exclusively a blueshifted SBC.

Very small blueshifted components are found in low-redshift  profiles of Pop. B AGN [Zamfir et al., 2008, Sulentic et al., 2004] and even in Population A, shifts at peak above 250  are very rare (the so-called “blue-outliers”; Zamanov et al., 2002). At high-redshift, Pop. B  profiles do present significant blueshifted SBC components but they still present different properties when compared to Pop. A sources: in our sample, the full profiles of Pop. A present a [OIII] FWHM $ \approx 2000$ km s$^{-1}$ while Pop. B profiles have FWHM $ \approx 1450$ km s$^{-1}$. The more remarkable difference is seen in the shifts at  9/10 and 1/2 intensities of the full profile ($c$(1/2) $\approx -850$ km s$^{-1}$ for Pop. A and $\approx -480$ km s$^{-1}$ for Pop. B). However, the A.I. of the two populations are almost the same, indicating that the lines present similar profile shapes.  The  emission of both Pop. A and Pop. B appears to be strongly affected (if not dominated) by outflowing gas.

An important consequence for redshift estimates is that the  lines should be avoided when considering high-$z$ quasars. In addition, three Pop. A (SDSSJ210524.49+000407.3, SDSSJ210831.56-063022.5, and SDSSJ235808.54+012507.2) and three Pop. B sources ([HB89] 0029+073, CTQ 0408, and SDSSJ153830.55+085517.0) present [Oiii]$\lambda 5007$ full profiles that can be well represented only by the blueshifted component (see the respective spectra in Figs. <ref>, <ref>, <ref>, and <ref> in the Appendix <ref>).

$W$() versus $c$(9/10). Blue and red squares indicate high-redshift Pop. A and Pop. B quasars from [Marziani et al., 2009] while grey and orange open squares represent low-$z$ sources from [Marziani et al., 2003], respectively. Color scheme for our sample as in Fig. <ref>. Error bars refer to 1$\sigma$ level of confidence and were estimated only for our sample.

FWHM of the full profile of  versus centroid at 1/2 flux intensity (c(1/2)) for the  emission line. Blue and red squares indicate high-redshift sources from [Marziani et al., 2009]. Dashed line represents a linear regression. Color scheme as in Fig. <ref>. Error bars refer to 1$\sigma$ level of confidence and were estimated only for our sample.

Fig. <ref> shows the relation between $W$([OIII]) and |$c$(9/10)| of . For our sample, the $W$([OIII]) ranges from $\approx$ 50Å  for some Pop. B sources to $< 1\r{A}$ for xAs, reaching the detection limit. It shares the same location as the high-redshift HE data. No clear difference between the location of Pop. A and Pop. B is confirmed by the median values of equivalent widths, 12Å vs. 10Å for Pop. A and B, respectively (the average $W$ is affected by the two A3 extremely faint sources with $W$([OIII]) $\lesssim 1$Å). At low $z$ (and low luminosity),  sources have considerably larger $W$ values but lower velocity centroids than the high-$z$ sample. Our sample  is located at the low end of the $W$([OIII]) distribution of low-$z$ sources as expected for luminous quasars [Shen & Ho, 2014], and in a shift range that at low $z$ is the exclusive domain of the rare, namesake “blue outliers” [Marziani et al., 2016].  Fig. <ref> also shows that the radio-loud quasars from our sample are very tightly grouped together with moderate blueshifts for high-$L$ quasars ($\lesssim 500$  at 0.9 fractional intensity).

A comparison between $c$(1/2) and FWHM of the  profiles is shown in Fig. <ref>. There is a strong correlation between the blueshift of [OIII], parameterised by the centroid at 1/2 intensity,  and the FWHM. The dashed line in the plot traces the linear regression between both parameters, derived from an unweighted least squares fit:

\begin{equation}
c(1/2)_{\rm [\ion{O}{III}]}\approx(-0.65\pm 0.08)\ \textrm{FWHM}({\rm [\ion{O}{III}]})+(530\pm 205),
\label{eq:oiii}
\end{equation}

Table <ref> lists this linear relation together with the other that involve also . We report the fitted parameters (Cols. 1 and 2), the method used (Col. 3), the linear correlation coefficients (Cols. 4 and 5), the rms (Col. 6), the Pearson $r$ score (Col. 7),  and its associated null hypothesis probability value (Col. 8).

Equation <ref> confirms several previous works [Komossa et al., 2008, Marziani et al., 2016] and  justifies the interpretation of the  profile in terms of a blueshifted semibroad component and of a narrow component [Zhang et al., 2011].

Linear relations ($y=a+b*x$) between different emission line properties.

y     x     Method     $a\pm \delta a$     $b \pm \delta b$     RMSE     CC     $\rho$-value

(1)     (2)     (3)     (4)     (5)     (6)     (7)     (8)

$c(1/2)_{\rm{[\ion{O}{iii}]}}$     $\rm{FWHM}(\rm{[\ion{O}{iii}]})$     Least squares     $530\pm 205$     $-0.65 \pm 0.08$     402     -0.86      $4.1 \times 10^{-7}$

$c(1/2)_{\rm{\ion{C}{IV}}}$     $\rm{FWHM}(\rm{\ion{C}{IV}})$     Least squares     $2000\pm 737^{(a)}$     $-0.68 \pm 0.10^{(a)}$     429     -0.90$^{(a)}$     $1.1 \times 10^{-4}$ $^{(a)}$

$\log W(\textrm{\ion{C}{IV}})$     $\log |c(1/2)|_{\rm{\ion{C}{IV}}}$     Bisector     $3.21 \pm 0.17^{(a)}$     $-0.58 \pm 0.05^{(a)}$     0.28     -0.64$^{(a)}$     $2.1 \times 10^{-12}$ $^{(a)}$

$\log W(\textrm{\ion{C}{IV}})$     $\log \textrm{FWHM(\ion{C}{IV})}$     Bisector     $8.31\pm 0.71^{(a)}$     $-1.84 \pm 0.19^{(a)}$     0.31     -0.49$^{(a)}$     $2.5 \times 10^{-7}$ $^{(a)}$

$c(1/2)_{\rm{\ion{C}{IV}}}$     $c(1/2)_{\rm{[\ion{O}{III}]}}$     Orthogonal     $-1239 \pm 276$     $1.50\pm 0.31$     1086     0.45     $4\times 10^{-3}$

$^{(a)}$ Only for Pop. A.

[]Spectrophotometric measurements on the UV region.

Source     $f_{\lambda,1750}$ $^{(a)}$     $f$(SiIV+OIV)$^{(b)}$     W(SiIV+OIV)     $f$(CIV)$^{(b)}$     $W$(CIV)     $f$(HeII)$^{(b)}$     $W$(HeII)     $f$(AlIII)$^{(b)}$       $W$(AlIII)     $f$(CIII])$^{(b)}$     $W$(CIII])     $f$(SiIII])$^{(b)}$     $W$(SiIII])

[Å]         [Å]         [Å]         [Å]         [Å]         [Å]

(1)     (2)     (3)     (4)     (5)     (6)     (7)     (8)     (9)     (10)     (11)     (12)     (13)     (14)

14cPopulation A

SDSSJ005700.18+143737.7$^{(e)}$	   	5.9	$\pm$	0.9	   	1.29	$\pm$	0.19	   	16	$\pm$	2	   	1.58	$\pm$	0.24	   	22	$\pm$	3	   	0.33	$\pm$	0.05	   	5	$\pm$	1	   	0.41	$\pm$	0.06	   	8	$\pm$	1	   	0.23	$\pm$	0.03	   	5	$\pm$	1	   	0.42	$\pm$	0.06	   	8	$\pm$	1

SDSSJ132012.33+142037.1	   	7.9	$\pm$	1.2	   	1.77	$\pm$	0.27	   	18	$\pm$	2	   	3.66	$\pm$	0.55	   	40	$\pm$	5	   	0.81	$\pm$	0.12	   	10	$\pm$	1	   	0.31	$\pm$	0.05	   	4	$\pm$	1	   	0.57	$\pm$	0.09	   	8	$\pm$	1	   	0.75	$\pm$	0.11	   	11	$\pm$	1

SDSSJ135831.78+050522.8	   	13.6	$\pm$	2.0	   	3.78	$\pm$	0.57	   	20	$\pm$	2	   	5.43	$\pm$	0.81	   	34	$\pm$	4	   	1.31	$\pm$	0.20	   	9	$\pm$	1	   	0.89	$\pm$	0.13	   	7	$\pm$	1	   	1.01	$\pm$	0.15	   	9	$\pm$	1	   	1.52	$\pm$	0.23	   	13	$\pm$	2

Q 1410+096	   	14.1	$\pm$	2.1	   	2.45	$\pm$	0.37	   	15	$\pm$	2	   	3.50	$\pm$	0.53	   	23	$\pm$	3	   	1.50	$\pm$	0.23	   	10	$\pm$	1	   	0.96	$\pm$	0.14	   	7	$\pm$	1	   	1.17	$\pm$	0.18	   	9	$\pm$	1	   	1.18	$\pm$	0.18	   	9	$\pm$	1

SDSSJ161458.33+144836.9	   	15.4	$\pm$	2.3	   	2.90	$\pm$	0.44	   	14	$\pm$	2	   	5.74	$\pm$	0.86	   	31	$\pm$	4	   	0.94	$\pm$	0.14	   	6	$\pm$	1	   	0.57	$\pm$	0.09	   	4	$\pm$	1	   	1.41	$\pm$	0.21	   	11	$\pm$	1	   	1.32	$\pm$	0.20	   	10	$\pm$	1

PKS 2000-330$^{(c)}$	   	-			   	3.20	$\pm$	0.48	   	4	$\pm$	2	   	4.50	$\pm$	0.68	   	19	$\pm$	2	   	-			   	-			   	-			   	-			   	-			   	-			   	-			   	-

SDSSJ210524.47+000407.3$^{(d)(e)}$	   	21.8	$\pm$	3.3	   	-			   	-			   	1.50	$\pm$	0.23	   	6	$\pm$	1	   	0.75	$\pm$	0.11	   	3	$\pm$	1	   	2.19	$\pm$	0.33	   	10	$\pm$	1	   	0.51	$\pm$	0.08	   	2	$\pm$	1	   	1.97	$\pm$	0.30	   	9	$\pm$	1

SDSSJ210831.56-063022.5$^{(e)}$	   	14.3	$\pm$	2.1	   	2.47	$\pm$	0.37	   	14	$\pm$	2	   	2.25	$\pm$	0.34	   	13	$\pm$	2	   	0.14	$\pm$	0.02	   	1	$\pm$	1	   	1.01	$\pm$	0.15	   	7	$\pm$	1	   	0.31	$\pm$	0.05	   	2	$\pm$	1	   	0.94	$\pm$	0.14	   	7	$\pm$	1

SDSSJ212329.46-005052.9	   	23.9	$\pm$	3.6	   	3.58	$\pm$	0.54	   	9	$\pm$	1	   	6.09	$\pm$	0.91	   	19	$\pm$	2	   	0.85	$\pm$	0.13	   	3	$\pm$	1	   	1.77	$\pm$	0.27	   	9	$\pm$	1	   	0.59	$\pm$	0.09	   	3	$\pm$	1	   	1.89	$\pm$	0.28	   	10	$\pm$	1

SDSSJ235808.54+012507.2	   	7.5	$\pm$	1.1	   	1.52	$\pm$	0.23	   	12	$\pm$	1	   	2.55	$\pm$	0.38	   	25	$\pm$	3	   	0.71	$\pm$	0.11	   	8	$\pm$	1	   	1.91	$\pm$	0.29	   	5	$\pm$	1	   	0.47	$\pm$	0.07	   	8	$\pm$	1	   	0.61	$\pm$	0.09	   	10	$\pm$	1

14cPopulation B

SDSSJ114358.52+052444.9	   	20.2	$\pm$	3.0	   	2.28	$\pm$	0.34	   	8	$\pm$	1	   	5.86	$\pm$	0.88	   	24	$\pm$	3	   	1.42	$\pm$	0.21	   	6	$\pm$	1	   	0.71	$\pm$	0.11	   	4	$\pm$	1	   	1.30	$\pm$	0.20	   	7	$\pm$	1	   	0.98	$\pm$	0.15	   	5	$\pm$	1

SDSSJ115954.33+201921.1	   	24.3	$\pm$	3.6	   	3.64	$\pm$	0.55	   	12	$\pm$	1	   	5.55	$\pm$	0.83	   	20	$\pm$	2	   	0.92	$\pm$	0.14	   	4	$\pm$	1	   	1.14	$\pm$	0.17	   	5	$\pm$	1	   	1.94	$\pm$	0.29	   	9	$\pm$	1	   	0.62	$\pm$	0.09	   	3	$\pm$	1

SDSSJ120147.90+120630.2	   	16.3	$\pm$	2.4	   	3.44	$\pm$	0.52	   	15	$\pm$	2	   	7.57	$\pm$	1.14	   	37	$\pm$	4	   	1.63	$\pm$	0.24	   	9	$\pm$	1	   	0.67	$\pm$	0.10	   	5	$\pm$	1	   	3.00	$\pm$	0.45	   	22	$\pm$	3	   	1.13	$\pm$	0.17	   	8	$\pm$	1

SDSSJ141546.24+112943.4$^{(d)}$	   	16.8	$\pm$	2.5	   	-			   	-			   	-			   	-			   	-			   	-			   	1.59	$\pm$	0.24	   	7	$\pm$	1	   	5.10	$\pm$	0.77	   	23	$\pm$	3	   	2.83	$\pm$	0.42	   	13	$\pm$	2

SDSSJ153830.55+085517.0$^{(f)}$	   	17.4	$\pm$	2.6	   	4.92	$\pm$	0.74	   	19	$\pm$	2	   	5.34	$\pm$	0.80	   	24	$\pm$	3	   	0.64	$\pm$	0.10	   	3	$\pm$	1	   	1.91	$\pm$	0.29	   	12	$\pm$	1	   	0.94	$\pm$	0.14	   	6	$\pm$	1	   	1.27	$\pm$	0.19	   	8	$\pm$	1

$^{(a)}$ In units of $10^{-15}$ erg s$^{-1}$ cm$^{-2}$ Å$^{-1}$. $^{(b)}$ In units of $10^{-13}$ erg s$^{-1}$ cm$^{-2}$. $^{(c)}$ The UV spectrum does not cover the 1900 Å blend. $^{(d)}$ Presents broad absorption lines in the regions of + and +. $^{(e)}$ We consider BLUE+BC when estimating fluxes and equivalent widths of  and SiIII]$\lambda1892$. $^{(f)}$ This source is optically classified as Pop. B, but the UV spectrum fits perfectly with the one of a Pop. A quasar.

[]Measurements on the 1900 Å blend.

3cAlIII$\lambda$1860 BLUE         3cAlIII$\lambda$1860 BC         3cSiIII]$\lambda$1892 BLUE        3cSiIII]$\lambda$1892 BC         3cCIII]$\lambda$1909 BC         3cCIII]$\lambda$1909 VBC         3cCIII]$\lambda$1909 NC

2-4 6-8 10-12 14-16 18-20 22-24 26-28 30-32

Source     $I/I_{\rm{tot}}$     FWHM     Shift         $I/I_{\rm{tot}}$     FWHM     Shift         $I/I_{\rm{tot}}$     FWHM     Shift         $I/I_{\rm{tot}}$     FWHM     Shift         $I/I_{\rm{tot}}$     FWHM     Shift         $I/I_{\rm{tot}}$     FWHM     Shift         $I/I_{\rm{tot}}$     FWHM     Shift         $I/I_{\rm{tot}}$     FWHM     Shift

[km s$^{-1}$]     [km s$^{-1}$]             [km s$^{-1}$]     [km s$^{-1}$]             [km s$^{-1}$]     [km s$^{-1}$]             [km s$^{-1}$]     [km s$^{-1}$]             [km s$^{-1}$]     [km s$^{-1}$]             [km s$^{-1}$]     [km s$^{-1}$]            [km s$^{-1}$]     [km s$^{-1}$]             [km s$^{-1}$]     [km s$^{-1}$]

(1)     (2)     (3)     (4)         (5)     (6)     (7)         (8)     (9)     (10)         (11)     (12)     (13)         (14)     (15)     (16)         (17)     (18)     (19)         (20)     (21)     (22)         (23)     (24)     (25)

32cPopulation A

SDSSJ005700.18+143737.7	   	0.47	$\pm$	0.04	   	3268	$\pm$	396	   	-1686	$\pm$	202	   	   	0.53	$\pm$	0.04	   	2792	$\pm$	283	   	0	$\pm$	10	   	   	0.36	$\pm$	0.07	   	3268	$\pm$	392	   	-1686	$\pm$	-202	   	   	0.64	$\pm$	0.13	   	2792	$\pm$	335	   	-3	$\pm$	11	   	   	1.00	$\pm$	0.18	   	2400	$\pm$	288	   	0	$\pm$	10	   	   	…			   	…			   	…			   	   	…			   	…			   	…			   	   	1.00	$\pm$	0.12	   	2792	$\pm$	335	   	1494	$\pm$	179

SDSSJ132012.33+142037.1	   	0.27	$\pm$	0.02	   	1731	$\pm$	210	   	-967	$\pm$	116	   	   	0.72	$\pm$	0.06	   	2029	$\pm$	206	   	0	$\pm$	10	   	   	0.00			   	…			   	…			   	   	0.08	$\pm$	0.02	   	3030	$\pm$	364	   	0	$\pm$	10	   	   	0.92	$\pm$	0.17	   	3030	$\pm$	364	   	0	$\pm$	10	   	   	…			   	…			   	…			   	   	…			   	…			   	…			   	   	1.00	$\pm$	0.12	   	3030	$\pm$	364	   	1876	$\pm$	225

SDSSJ135831.78+050522.8	   	0.00			   	…			   	…			   	   	1.00	$\pm$	0.08	   	4225	$\pm$	428	   	0	$\pm$	10	   	   	0.00			   	…			   	…			   	   	1.00	$\pm$	0.21	   	4225	$\pm$	507	   	0	$\pm$	10	   	   	1.00	$\pm$	0.18	   	2720	$\pm$	326	   	0	$\pm$	10	   	   	…			   	…			   	…			   	   	…			   	…			   	…			   	   	1.00	$\pm$	0.12	   	4231	$\pm$	508	   	1033	$\pm$	124

Q 1410+096	   	0.00			   	…			   	…			   	   	1.00	$\pm$	0.08	   	2604	$\pm$	264	   	279	$\pm$	33	   	   	0.00			   	…			   	…			   	   	1.00	$\pm$	0.21	   	2604	$\pm$	312	   	279	$\pm$	33	   	   	1.00	$\pm$	0.18	   	2604	$\pm$	312	   	278	$\pm$	58	   	   	…			   	…			   	…			   	   	…			   	…			   	…			   	   	1.00	$\pm$	0.12	   	1607	$\pm$	193	   	1253	$\pm$	150

SDSSJ161458.33+144836.9	   	0.00			   	…			   	…			   	   	1.00	$\pm$	0.08	   	3374	$\pm$	342	   	0	$\pm$	10	   	   	0.00			   	…			   	…			   	   	1.00	$\pm$	0.21	   	3374	$\pm$	405	   	0	$\pm$	10	   	   	1.00	$\pm$	0.18	   	3319	$\pm$	398	   	0	$\pm$	10	   	   	…			   	…			   	…			   	   	…			   	…			   	…			   	   	0.00			   	…			   	…

SDSSJ210524.49+000407.3	   	0.61	$\pm$	0.05	   	4365	$\pm$	529	   	-2003	$\pm$	240	   	   	0.39	$\pm$	0.03	   	3672	$\pm$	372	   	0	$\pm$	10	   	   	0.23	$\pm$	0.04	   	3415	$\pm$	410	   	-2002	$\pm$	-240	   	   	0.77	$\pm$	0.16	   	4169	$\pm$	500	   	0	$\pm$	10	   	   	1.00	$\pm$	0.18	   	2577	$\pm$	309	   	0	$\pm$	10	   	   	…			   	…			   	…			   	   	…			   	…			   	…			   	   	1.00	$\pm$	0.12	   	3672	$\pm$	441	   	771	$\pm$	93

SDSSJ210831.56-063022.5	   	0.36	$\pm$	0.03	   	3181	$\pm$	386	   	-1951	$\pm$	234	   	   	0.64	$\pm$	0.05	   	4173	$\pm$	423	   	0	$\pm$	10	   	   	0.21	$\pm$	0.04	   	3187	$\pm$	382	   	-1951	$\pm$	-234	   	   	0.79	$\pm$	0.17	   	4173	$\pm$	501	   	0	$\pm$	10	   	   	1.00	$\pm$	0.18	   	3156	$\pm$	379	   	0	$\pm$	10	   	   	…			   	…			   	…			   	   	…			   	…			   	…			   	   	1.00	$\pm$	0.12	   	2177	$\pm$	261	   	2102	$\pm$	252

SDSSJ212329.46-005052.9	   	0.00			   	…			   	…			   	   	1.00	$\pm$	0.08	   	5122	$\pm$	519	   	0	$\pm$	10	   	   	0.00			   	…			   	…			   	   	1.00	$\pm$	0.21	   	5122	$\pm$	615	   	0	$\pm$	10	   	   	1.00	$\pm$	0.18	   	3125	$\pm$	375	   	0	$\pm$	10	   	   	…			   	…			   	…			   	   	…			   	…			   	…			   	   	0.00			   	…			   	…

SDSSJ235808.54+012507.2	   	0.00			   	…			   	…			   	   	1.00	$\pm$	0.08	   	3243	$\pm$	329	   	0	$\pm$	10	   	   	0.00			   	…			   	…			   	   	1.00	$\pm$	0.21	   	3243	$\pm$	389	   	0	$\pm$	10	   	   	1.00	$\pm$	0.18	   	3243	$\pm$	389	   	0	$\pm$	10	   	   	…			   	…			   	…			   	   	…			   	…			   	…			   	   	1.00	$\pm$	0.12	   	3204	$\pm$	384	   	111	$\pm$	13

Median     0.00 $\pm$ 0.36     3224 $\pm$ 723     -1818 $\pm$ 457         1.00 $\pm$ 0.36     3374 $\pm$ 1381     …         0.23 $\pm$ 0.07     3268 $\pm$ 114     -1951 $\pm$ 158         …     3374 $\pm$ 1381     …          …     2760 $\pm$ 552     …         …     …     …         …     …     …         …     2298 $\pm$ 1224     1143 $\pm$ 597

32cPopulation B

SDSSJ114358.52+052444.9	   	0.00			   	…			   	…			   	   	1.00	$\pm$	0.08	   	3967	$\pm$	402	   	0	$\pm$	10	   	   	0.00			   	…			   	…			   	   	1.00	$\pm$	0.18	   	3967	$\pm$	476	   	-3	$\pm$	11	   	   	0.50	$\pm$	0.10	   	3967	$\pm$	476	   	0	$\pm$	10	   	   	0.50	$\pm$	0.05	   	7038	$\pm$	1253	   	2842	$\pm$	369	   	   	0.02	$\pm$	0.01	   	1000	$\pm$	178	   	0	$\pm$	10	   	   	0.00			   	…			   	…

SDSSJ115954.33+201921.1	   	0.00			   	…			   	…			   	   	1.00	$\pm$	0.08	   	4999	$\pm$	506	   	0	$\pm$	10	   	   	0.00			   	…			   	…			   	   	1.00	$\pm$	0.18	   	4999	$\pm$	600	   	0	$\pm$	10	   	   	0.64	$\pm$	0.13	   	4999	$\pm$	600	   	0	$\pm$	10	   	   	0.36	$\pm$	0.03	   	6563	$\pm$	1168	   	1998	$\pm$	260	   	   	0.01	$\pm$	0.01	   	733	$\pm$	130	   	0	$\pm$	10	   	   	0.00			   	…			   	…

SDSSJ120147.90+120630.2	   	0.00			   	…			   	…			   	   	1.00	$\pm$	0.08	   	3999	$\pm$	405	   	0	$\pm$	10	   	   	0.00			   	…			   	…			   	   	1.00	$\pm$	0.18	   	3999	$\pm$	480	   	0	$\pm$	10	   	   	0.70	$\pm$	0.14	   	3999	$\pm$	480	   	0	$\pm$	10	   	   	0.30	$\pm$	0.03	   	7046	$\pm$	1254	   	2207	$\pm$	287	   	   	0.01	$\pm$	0.01	   	999	$\pm$	178	   	0	$\pm$	10	   	   	0.00			   	…			   	…

SDSSJ141546.24+112943.4	   	0.00			   	…			   	…			   	   	1.00	$\pm$	0.08	   	5105	$\pm$	517	   	0	$\pm$	10	   	   	0.00			   	…			   	…			   	   	1.00	$\pm$	0.18	   	5105	$\pm$	613	   	0	$\pm$	10	   	   	0.64	$\pm$	0.13	   	4101	$\pm$	492	   	0	$\pm$	10	   	   	0.36	$\pm$	0.03	   	7365	$\pm$	1311	   	3134	$\pm$	407	   	   	0.10	$\pm$	0.01	   	1062	$\pm$	189	   	0	$\pm$	10	   	   	0.00			   	…			   	…

SDSSJ153830.55+085517.0$^{(a)}$	   	0.00			   	…			   	…			   	   	1.00	$\pm$	0.08	   	3085	$\pm$	313	   	0	$\pm$	10	   	   	0.00			   	…			   	…			   	   	1.00	$\pm$	0.18	   	3085	$\pm$	370	   	0	$\pm$	10	   	   	1.00	$\pm$	0.20	   	3104	$\pm$	372	   	28	$\pm$	16	   	   	…			   	…			   	…			   	   	0.00			   	…			   	…			   	   	1.00	$\pm$	0.12	   	3141	$\pm$	377	   	783	$\pm$	94

Median     …     …     …         …     3999 $\pm$ 1032     …         …     …     …         …     3999 $\pm$ 1032     …          0.64 $\pm$ 0.06     3999 $\pm$ 134     …         0.36 $\pm$ 0.05     7042 $\pm$ 206     2524 $\pm$ 760         …     999 $\pm$ 83     …         …     …     …

$^{(a)}$ UV line profiles of this source were fitted with Lorentzian shapes. See note in the Appendix <ref> (Fig. <ref>)

§.§ UV

The fits for the UV emission lines are shown in Appendix <ref> together with the full UV spectra of the 15 available sources  (10 Pop. A and 5 Pop. B). Spectrophotometric measurements in the UV region are reported in Table <ref> and concern the 1900 Å blend, Civ$\lambda1549$+HeII$\lambda1640$, as well as flux intensity and equivalent width of SiIV+OIV (Cols. 3-4), CIV (Cols. 5-6), HeII (Cols. 7-8), AlIII (Cols. 9-10), CIII] (Cols. 11-12), and SiIII (Cols 13-14).

§.§.§ 1900 Å blend

Table <ref> presents the measurements resulting from the  analysis of the 1900 Å blend. Intensities, FWHM, and shifts are shown for the emission line profiles and their components, whenever the profile presents more than just one component. Cols. 2 to 4 list relative intensity, FWHM and shift of the blueshifted component of AlIII$\lambda1860$; Cols. 5 to 7 show the broad component of AlIII$\lambda1860$; Cols. 8 to 10 for SiIII]$\lambda$1892 BLUE; Cols. 11 to 13 for SiIII]$\lambda$1892 BC; Cols. 14 to 16, the BC of CIII]$\lambda$1909; Cols. 17 to 19, the VBC of CIII]$\lambda$1909; Cols. 20 to 22, the NC of CIII]$\lambda$1909;  and, finally, Cols. 23 to 25 for a FeIII]$\lambda$1914 emission line component.

The AlIII$\lambda1860$ contribution can be well fitted assuming only a BC for all Pop. A sources but four: SDSSJ005700.18+143737.7, SDSSJ210524.49+000407.3, SDSSJ210831.56-063022.5, and SDSSJ132012.33+142037.1. These same three sources are the ones that are located in the A3 region of the quasar MS. In these cases, we need to add a BLUE component with $3000 \le $ FWHM $ \le 4500$ km s$^{-1}$ in the AlIII$\lambda$1860 doublet and in the SiIII]$\lambda$1892  emission line profile. We have imposed the same FWHM for both components.

The Pop. A CIII]$\lambda$1909  profile can be well reproduced by a strong BC at rest-frame in combination with a component that accounts for the FeIII$\lambda$1914 contributions in its red wing. The motivation to include the FeIII$\lambda$1914 line resides in the selective enhancement due to Lyman $\alpha$ fluorescence that is well-known to affect the UV FeII emission and FeIII emission as well [Sigut & Pradhan, 1998, Sigut et al., 2004]. Of the FeII features the UV multiplet 191 at $\lambda$1785 is known to be enhanced by Ly$\alpha$ fluorescence: a strong  UV multiplet 191 may suggest a strong FeIII$\lambda$1914 line.
There is an overall consistency between the presence of the FeIII$\lambda$1914 line and the detection of the  feature (8 out of 10 Pop. A sources with UV suitable data have both).
However, the relative contribution of the CIII]$\lambda$1909 and FeIII$\lambda$1914 remains difficult to ascertain because the two lines are severely blended together and some FeIII$\lambda$1914 emission is already included in the FeIII template.

For Pop. B sources,  and SiIII]$\lambda$1892 are well represented by only one component and in the five cases these emission lines  share the same FWHM and are centred at the respective rest-frame wavelength. However, the CIII]$\lambda$1909  VBC is systematically less broad than the  VBC: average FWHM is $\approx 7000$  for CIII] versus $\approx 12000$ for .

[]Measurements on the CIV$\lambda1549$+HeII$\lambda1640$ full line profiles and specfit analysis.

12cCIV$\lambda1549$     12cHeII$\lambda1640$

10-20 22-32

8cCIV$\lambda1549$ full profile     3cBLUE         3cBC         3cVBC         3cBLUE         3cBC         3cVBC

2-8 10-12 14-16 18-20 22-24 26-28 30-32

Source      FWHM     A. I.     Kurt.     c($\frac{1}{4}$)     c($\frac{1}{2}$)     c($\frac{3}{4}$)     c($\frac{9}{10}$)         $I/I_{\mathrm{tot}}$     FWHM     Shift         $I/I_{\mathrm{tot}}$     FWHM     Shift         $I/I_{\mathrm{tot}}$     FWHM     Shift         $I/I_{\mathrm{tot}}$     FWHM     Shift         $I/I_{\mathrm{tot}}$     FWHM     Shift         $I/I_{\mathrm{tot}}$     FWHM     Shift

[km s$^{-1}$]               [km s$^{-1}$]     [km s$^{-1}$]     [km s$^{-1}$]     [km s$^{-1}$]             [km s$^{-1}$]     [km s$^{-1}$]               [km s$^{-1}$]     [km s$^{-1}$]               [km s$^{-1}$]     [km s$^{-1}$]               [km s$^{-1}$]     [km s$^{-1}$]               [km s$^{-1}$]     [km s$^{-1}$]               [km s$^{-1}$]     [km s$^{-1}$]

(1)     (2)     (3)     (4)     (5)     (6)     (7)     (8)         (9)     (10)     (11)         (12)     (13)     (14)         (15)     (16)     (17)         (18)     (19)     (20)         (21)     (22)     (23)         (24)     (25)     (26)

32cPopulation A

SDSSJ005700.18+143737.7	   	8648	$\pm$	562	   	-0.38	$\pm$	0.01	   	0.40	$\pm$	0.01	   	-4951	$\pm$	334	   	-3994	$\pm$	181	   	-3272	$\pm$	272	   	-2604	$\pm$	326	   	   	0.81	$\pm$ 	0.05	   	13187	$\pm$ 	1846	   	-2318	$\pm$ 	278	   	   	0.19	$\pm$ 	0.05	   	2808	$\pm$ 	298	   	0	$\pm$ 	10	   	   	…			   	…			   	…			   	   	0.67	$\pm$ 	0.04	   	13187	$\pm$ 	1846	   	-4249	$\pm$ 	510	   	   	0.33	$\pm$ 	0.02	   	2808	$\pm$ 	298	   	0	$\pm$	10	   	   	…			   	…			   	…

SDSSJ132012.33+142037.1	   	5549	$\pm$	399	   	-0.36	$\pm$	0.01	   	0.37	$\pm$	0.01	   	-2956	$\pm$	263	   	-2407	$\pm$	124	   	-1830	$\pm$	177	   	-1419	$\pm$	190	   	   	0.72	$\pm$ 	0.04	   	8739	$\pm$ 	1223	   	-1446	$\pm$ 	174	   	   	0.28	$\pm$ 	0.03	   	3278	$\pm$ 	348	   	0	$\pm$	10	   	   	…			   	…			   	…			   	   	0.60	$\pm$ 	0.04	   	9837	$\pm$ 	1377	   	-3388	$\pm$ 	407	   	   	0.40	$\pm$ 	0.02	   	3278	$\pm$ 	348	   	0	$\pm$	10	   	   	…			   	…			   	…

SDSSJ135831.78+050522.8	   	7365	$\pm$	655	   	-0.27	$\pm$	0.03	   	0.30	$\pm$	0.01	   	-3188	$\pm$	416	   	-2460	$\pm$	190	   	-1808	$\pm$	256	   	-1556	$\pm$	187	   	   	0.52	$\pm$ 	0.03	   	11983	$\pm$ 	1678	   	-1909	$\pm$ 	229	   	   	0.48	$\pm$ 	0.02	   	4404	$\pm$ 	468	   	0	$\pm$	10	   	   	…			   	…			   	…			   	   	0.55	$\pm$ 	0.03	   	11983	$\pm$ 	1678	   	-3386	$\pm$ 	406	   	   	0.45	$\pm$ 	0.03	   	4404	$\pm$ 	468	   	0	$\pm$	10	   	   	…			   	…			   	…

Q 1410+096	   	6311	$\pm$	552	   	-0.18	$\pm$	0.05	   	0.33	$\pm$	0.01	   	-2604	$\pm$	374	   	-1746	$\pm$	179	   	-1052	$\pm$	172	   	-1691	$\pm$	90	   	   	0.41	$\pm$ 	0.03	   	10881	$\pm$ 	1523	   	-1526	$\pm$ 	183	   	   	0.59	$\pm$ 	0.01	   	3293	$\pm$ 	350	   	0	$\pm$	10	   	   	…			   	…			   	…			   	   	0.53	$\pm$ 	0.03	   	9369	$\pm$ 	1312	   	-7880	$\pm$ 	946	   	   	0.47	$\pm$ 	0.03	   	3292	$\pm$ 	350	   	0	$\pm$	10	   	   	…			   	…			   	…

SDSSJ161458.33+144836.9	   	5790	$\pm$	554	   	-0.27	$\pm$	0.03	   	0.30	$\pm$	0.02	   	-2779	$\pm$	327	   	-2394	$\pm$	139	   	-1894	$\pm$	190	   	-1519	$\pm$	168	   	   	0.59	$\pm$ 	0.04	   	9333	$\pm$ 	1307	   	-1609	$\pm$ 	193	   	   	0.41	$\pm$ 	0.01	   	3816	$\pm$ 	406	   	0	$\pm$	10	   	   	…			   	…			   	…			   	   	0.66	$\pm$ 	0.04	   	9556	$\pm$ 	1338	   	-5483	$\pm$ 	658	   	   	0.34	$\pm$ 	0.02	   	3816	$\pm$ 	406	   	0	$\pm$	10	   	   	…			   	…			   	…

PKS 2000-330	   	4950	$\pm$	346	   	-0.33	$\pm$	0.01	   	0.39	$\pm$	0.01	   	-2373	$\pm$	226	   	-1923	$\pm$	104	   	-1465	$\pm$	154	   	-1155	$\pm$	169	   	   	0.70	$\pm$ 	0.04	   	7340	$\pm$ 	1028	   	-1300	$\pm$ 	156	   	   	0.30	$\pm$ 	0.02	   	3142	$\pm$ 	334	   	0	$\pm$	10	   	   	…			   	…			   	…			   	   	…			   	…			   	…			   	   	…			   	…			   	…			   	   	…			   	…			   	…

SDSSJ210524.49+000407.3	   	8443	$\pm$	592	   	-0.15	$\pm$	0.01	   	0.43	$\pm$	0.01	   	-5060	$\pm$	297	   	-4695	$\pm$	134	   	-4452	$\pm$	228	   	-4175	$\pm$	279	   	   	0.89	$\pm$ 	0.05	   	10418	$\pm$ 	1459	   	-3926	$\pm$ 	471	   	   	0.11	$\pm$ 	0.02	   	3504	$\pm$ 	372	   	-82	$\pm$ 	20	   	   	…			   	…			   	…			   	   	0.55	$\pm$ 	0.03	   	10418	$\pm$ 	1459	   	-8749	$\pm$ 	1050	   	   	0.45	$\pm$ 	0.03	   	3504	$\pm$ 	372	   	-81	$\pm$ 	20	   	   	…			   	…			   	…

SDSSJ210831.56-063022.5	   	9389	$\pm$	619	   	-0.30	$\pm$	0.01	   	0.42	$\pm$	0.01	   	-5744	$\pm$	365	   	-4982	$\pm$	177	   	-4284	$\pm$	264	   	-3709	$\pm$	334	   	   	0.87	$\pm$ 	0.05	   	13618	$\pm$ 	1907	   	-3250	$\pm$ 	390	   	   	0.13	$\pm$ 	0.01	   	4340	$\pm$ 	461	   	0	$\pm$	10	   	   	…			   	…			   	…			   	   	0.70	$\pm$ 	0.04	   	13618	$\pm$ 	1907	   	-3250	$\pm$ 	390	   	   	0.30	$\pm$ 	0.02	   	4340	$\pm$ 	461	   	0	$\pm$	10	   	   	…			   	…			   	…

SDSSJ212329.46-005052.9	   	7978	$\pm$	524	   	-0.21	$\pm$	0.01	   	0.42	$\pm$	0.01	   	-3752	$\pm$	332	   	-3311	$\pm$	139	   	-2876	$\pm$	231	   	-2551	$\pm$	277	   	   	0.72	$\pm$ 	0.04	   	10217	$\pm$ 	1430	   	-2694	$\pm$ 	323	   	   	0.28	$\pm$ 	0.01	   	5457	$\pm$ 	580	   	0	$\pm$	10	   	   	…			   	…			   	…			   	   	0.63	$\pm$ 	0.04	   	10217	$\pm$ 	1430	   	-4233	$\pm$ 	508	   	   	0.37	$\pm$ 	0.02	   	5457	$\pm$ 	580	   	0	$\pm$	10	   	   	…			   	…			   	…

SDSSJ235808.54+012507.2	   	6504	$\pm$	398	   	-0.25	$\pm$	0.01	   	0.44	$\pm$	0.01	   	-3197	$\pm$	245	   	-2727	$\pm$	114	   	-2312	$\pm$	186	   	-2029	$\pm$	235	   	   	0.80	$\pm$ 	0.05	   	8302	$\pm$ 	1162	   	-2163	$\pm$ 	260	   	   	0.20	$\pm$ 	0.01	   	3468	$\pm$ 	369	   	0	$\pm$	10	   	   	…			   	…			   	…			   	   	0.49	$\pm$ 	0.03	   	9231	$\pm$ 	1292	   	-5323	$\pm$ 	639	   	   	0.51	$\pm$ 	0.03	   	3468	$\pm$ 	369	   	0	$\pm$	10	   	   	…			   	…			   	…

Median     6934 $\pm$ 2406     -0.27 $\pm$ 0.10     0.39 $\pm$ 0.08     -3192 $\pm$ 1828     -2593 $\pm$ 1426     -2103 $\pm$ 1359     -1860 $\pm$ 1062         0.72 $\pm$ 0.19     10317 $\pm$ 2820     -2036 $\pm$ 1053         0.28 $\pm$ 0.19     3486 $\pm$ 927     …         …     …     …         0.60 $\pm$ 0.11     10217 $\pm$ 2427     -4249 $\pm$ 2095         0.4 $\pm$ 0.11     3504 $\pm$ 1048     …         …     …     …

32cPopulation B

SDSSJ114358.52+052444.9	   	7078	$\pm$	766	   	-0.30	$\pm$	0.05	   	0.27	$\pm$	0.01	   	-3049	$\pm$	511	   	-2059	$\pm$	230	   	-1375	$\pm$	204	   	-1147	$\pm$	185	   	   	0.60	$\pm$ 	0.06	   	14345	$\pm$ 	1037	   	-1497	$\pm$ 	180	   	   	0.24	$\pm$ 	0.04	   	5055	$\pm$ 	365	   	0	$\pm$	10	   	   	0.16	$\pm$ 	0.02	   	11848	$\pm$ 	2109	   	3822	$\pm$ 	515	   	   	0.57	$\pm$ 	0.06	   	14345	$\pm$ 	1037	   	-3216	$\pm$ 	433	   	   	0.17	$\pm$ 	0.02	   	5055	$\pm$ 	365	   	0	$\pm$	10	   	   	0.26	$\pm$ 	0.03	   	11848	$\pm$ 	2109	   	2540	$\pm$ 	342

SDSSJ115954.33+201921.1	   	5741	$\pm$	585	   	-0.08	$\pm$	0.05	   	0.29	$\pm$	0.01	   	-1671	$\pm$	444	   	-1851	$\pm$	122	   	-1516	$\pm$	166	   	-1253	$\pm$	174	   	   	0.54	$\pm$ 	0.05	   	9933	$\pm$ 	718	   	-1307	$\pm$ 	157	   	   	0.32	$\pm$ 	0.05	   	5716	$\pm$ 	413	   	0	$\pm$	10	   	   	0.14	$\pm$ 	0.01	   	8458	$\pm$ 	1506	   	4397	$\pm$ 	592	   	   	0.36	$\pm$ 	0.04	   	9933	$\pm$ 	718	   	-1307	$\pm$ 	176	   	   	0.07	$\pm$ 	0.01	   	5716	$\pm$ 	413	   	0	$\pm$	10	   	   	0.58	$\pm$ 	0.06	   	8458	$\pm$ 	1506	   	4397	$\pm$ 	592

SDSSJ120147.90+120630.2	   	4995	$\pm$	475	   	-0.08	$\pm$	0.04	   	0.32	$\pm$	0.01	   	-1354	$\pm$	284	   	-1133	$\pm$	104	   	-1061	$\pm$	148	   	-1015	$\pm$	132	   	   	0.50	$\pm$ 	0.05	   	7464	$\pm$ 	540	   	-1454	$\pm$ 	174	   	   	0.35	$\pm$ 	0.05	   	3945	$\pm$ 	285	   	0	$\pm$	10	   	   	0.15	$\pm$ 	0.01	   	6710	$\pm$ 	1194	   	1508	$\pm$ 	203	   	   	0.44	$\pm$ 	0.04	   	7464	$\pm$ 	540	   	-4676	$\pm$ 	630	   	   	0.09	$\pm$ 	0.01	   	3945	$\pm$ 	285	   	0	$\pm$	10	   	   	0.47	$\pm$ 	0.05	   	6710	$\pm$ 	1194	   	1508	$\pm$ 	203

SDSSJ153830.55+085517.0	   	5819	$\pm$	448	   	-0.41	$\pm$	0.02	   	0.35	$\pm$	0.02	   	-2841	$\pm$	303	   	-2108	$\pm$	147	   	-1381	$\pm$	187	   	-961	$\pm$	185	   	   	0.68	$\pm$ 	0.07	   	10024	$\pm$ 	725	   	-992	$\pm$ 	119	   	   	0.32	$\pm$ 	0.05	   	4313	$\pm$ 	312	   	0	$\pm$	10	   	   	…			   	…			   	…			   	   	0.48	$\pm$ 	0.05	   	10024	$\pm$ 	725	   	-992	$\pm$ 	134	   	   	0.52	$\pm$ 	0.08	   	4313	$\pm$ 	312	   	0	$\pm$	10	   	   	…			   	…			   	…

Median      5780 $\pm$ 1474     -0.17 $\pm$ 0.21     0.30 $\pm$ 0.06     -2256 $\pm$ 1563     -1955 $\pm$ 783     -1378 $\pm$ 342     -1081 $\pm$ 252         0.57 $\pm$ 0.15     9978 $\pm$ 2162     -1380 $\pm$ 415         0.30 $\pm$ 0.07     4129 $\pm$ 1268     …         0.15 $\pm$ 0.01     8458 $\pm$ 2569     3822 $\pm$ 1444         0.46 $\pm$ 0.16     9978 $\pm$ 2087     -2261 $\pm$ 2920         0.14 $\pm$ 0.24     4129 $\pm$ 1255     …         0.47 $\pm$ 0.16     8458 $\pm$ 2569     2540 $\pm$ 1444

§.§.§ CIV$\lambda1549$+HeII$\lambda1640$

Top: Relation between centroid velocity at 1/2 intensity ($c$(1/2)) and rest-frame equivalent width of . Bottom: FWHM of  versus $W$(CIV). Colour scheme for our sample as in Fig. <ref>. Filled magenta squares indicate data from [Martínez-Aldama et al., 2018]. Blue and red open squares represent Pop. A and Pop. B HE sources from [Sulentic et al., 2017]. Low-$z$ FOS data from [Sulentic et al., 2007] are represented by grey (Pop. A) and orange (Pop. B) squares. Green point-dashed lines indicate the linear regression obtained through the bisector method including only the Pop. A sources from the four samples.  Error bars refer to 1$\sigma$ level of confidence and were estimated only for our sample.

Centroid velocity at 1/2 flux intensity,  $c$(1/2), for the  emission line versus FWHM of the full profile of . Filled circles represent our sample and the colour scheme is the same as in Fig. <ref>. Blue and red open squares are high-redshift sources from [Sulentic et al., 2017]. Low-$z$ Pop. A and Pop. B are represented by grey and orange open squares, respectively. Dashed line represents the least squares linear regression presented in Eq. <ref>, including only Pop. A sources. Error bars refer to 1$\sigma$ level of confidence for our sample.

Measurements on the CIV$\lambda1549$+HeII$\lambda1640$ blend are reported in Table <ref>. As for H$\beta$, we list FWHM (Col. 2), A.I. (Col. 3), kurtosis (Col. 4), and centroids $c$(1/4), $c$(1/2), $c$(3/4) and $c$(9/10) in Cols. 5 to 8 for the CIV$\lambda1549$ full line profile. Information on individual components is also given for both CIV$\lambda1549$ and HeII$\lambda1640$. Cols. 9 to 11 give the relative intensity $I/I_{\mathrm{tot}}$, FWHM, and shift for CIV$\lambda1549$ BLUE; Cols. 12 to 14 for CIV$\lambda1549$ BC; Cols. 15 to 17 for CIV$\lambda1549$ VBC; Cols. 18 to 20 for HeII$\lambda1640$ BLUE; Cols. 21 to 23 for HeII$\lambda1640$ BC; and Cols. 24 to 26 for HeII$\lambda1640$ VBC.

We have ten out of 12 Pop. A sources and four out of ten Pop. B quasars with CIV covered for analysis.   The fits are remarkably good and allow for the “plateau” found as an extension of the red wing of  close to 1575 Å, which can usually be well reproduced by fitting CIV$\lambda1549$ and HeII$\lambda1640$ with the same FWHM for blueshifted, broad, and very broad components [Fine et al., 2010, Marziani et al., 2010].  In general, Pop. A objects present a larger FWHM of the full profile, always $\ge$ 4900 km s$^{-1}$, with respect to Pop. B. Pop. A are also those that in general present higher asymmetries and shifts towards the blue.  Apart from SDSSJ212329.46-005052.9, all Pop. A sources present a FWHM(CIV$_{\rm{BC}}$) $\le 4500$ km s$^{-1}$.  The Pop. A3 SDSSJ210831.56-063022.5 is the source with the strongest blueshift, reaching $c$(1/2) $\approx -4980$ km s$^{-1}$ and with similar values of fractional intensities along the profile (as can be seen in the top plot of Fig. <ref>).
In the case of Pop. B sources, we have found that the VBC accounts for only $\sim 15$% of the full profile. The widest VBC FWHM is seen in SDSSJ114358.52+052444.9, which reaches 11848 km s$^{-1}$ with a shift of 3822 km s$^{-1}$. This same source is the one that also presents  the broadest FWHM of the BLUE (14345 km s$^{-1}$) and larger shift ($-1497$ km s$^{-1}$). In all Pop. B cases, the BLUE component accounts for at least 50% of the  full profile, but still a fraction that is lower than in Pop. A ($\sim$ 70 %). Correspondingly, the Pop. A  profiles in general present higher blueshifts and asymmetry indexes than the ones measured in Pop. B.

The top and bottom panels from Fig. <ref> show the relation between the rest-frame equivalent widths of  and the centroid velocities at 1/2 peak intensity ($c$(1/2)) and FWHM respectively). We also include in the figure the bright, high-$z$ xA sample of [Martínez-Aldama et al., 2018] as well as the high-$z$ data from [Sulentic et al., 2017] and the FOS low-$z$ data from [Sulentic et al., 2007].  Our data are in good agreement with the ones of [Martínez-Aldama et al., 2018] and [Sulentic et al., 2017]. Our sample together with the high-$L$ comparison samples, presents smaller values of  equivalent width when compared with the FOS data. Additionally, the high-$z$, high-$L$ sources are those that present the most blueshifted  profiles among all quasars [Shen et al., 2011, Rankine et al., 2020, Vietri et al., 2018, Vietri et al., 2020]. The Pearson correlation coefficient between $W$ and $c$(1/2) of   for the Pop. A sources is -0.64 (with $\rho=2.1\times 10^{-12}$) and their relation is given in Table <ref>.

There is also a correlation between $W$ and FWHM  with $r \approx -0.49$, if we restrict the samples to only Pop. A objects (Table <ref>).

Fig. <ref> presents the strong correlation between FWHM and $c$(1/2) of the  line, with a Pearson $r \approx$ -0.90 for high-$z$ Pop. A sources:

\begin{equation}
\label{eq:c12fwhm_civ}
c(1/2)_{\rm \ion{C}{IV}} =(-0.68\pm 0.10) \textrm{FWHM}({\rm{\ion{C}{IV}}})+(2000\pm 737)
\end{equation}

This relation is in good agreement with previous results <cit.>. As the blueshift of  increases, FWHM() is likely to increase as well. Both  FWHM and  blueshift  parameterised by $c$(1/2)  show a clear increase from spectral types A1 to A3, the latter being those with the highest blueshifts (median value $\approx$ $-4500$ km s$^{-1}$) and the widest FWHM (median $\approx$ 9000 km s$^{-1}$).

In the case of  in Pop. B sources, the shifts at 1/2 flux intensities are also displaced towards blue wavelengths with average value of $c$(1/2) $=-1681$ km s$^{-1}$ and mean  FWHM $\approx 5940$ , somewhat smaller than for Pop. A.
However, the $c$(1/2) values for the Pop. B sources from our sample are still higher than the majority of the low-luminosity and low-redshift quasars, which usually present a $c$(1/2) $\le 200$ km s$^{-1}$. Low-luminosity Pop. B spectra show a sort of dichotomy in the   shift  distribution: a fraction of sources remains unshifted or with modest shifts to the blue (the orange and grey “cloud” of points in Fig. <ref>). The FOS low-luminosity and low-redshift sources tend to present smaller $c$(1/2) in the  emission line when compared with our data. This indicates that the  blueshifted components seen in higher-luminosity sources are more prominent  than the ones observed in quasars of lower  luminosities.

[]Measurements on the full profiles of  SiIV$\lambda1397$+OIV]$\lambda1402$.

Source     FWHM     A.I.     Kurtosis     $c$(1/2)     $c$(9/10)

[km s$^{-1}$]             [km s$^{-1}$]      [km s$^{-1}$]

(1)     (2)     (3)     (4)     (5)     (6)

6cPopulation A

SDSSJ005700.18+143737.7	   	8659	$\pm$	1202	   	-0.34	$\pm$	0.02	   	0.36	$\pm$	0.03	   	-2110	$\pm$	377	   	-858	$\pm$	443

SDSSJ132012.33+142037.1	   	5128	$\pm$	859	   	-0.26	$\pm$	0.05	   	0.34	$\pm$	0.01	   	-376	$\pm$	249	   	131	$\pm$	293

SDSSJ135831.78+050522.8	   	7438	$\pm$	1658	   	-0.27	$\pm$	0.07	   	0.31	$\pm$	0.01	   	-150	$\pm$	534	   	499	$\pm$	395

Q 1410+096	   	5430	$\pm$	790	   	0.00	$\pm$	0.09	   	0.40	$\pm$	0.01	   	750	$\pm$	157	   	666	$\pm$	335

SDSSJ161458.33+144836.9	   	7370	$\pm$	860	   	-0.26	$\pm$	0.06	   	0.48	$\pm$	0.01	   	-392	$\pm$	227	   	680	$\pm$	844

PKS 2000-330	   	3494	$\pm$	329	   	0.32	$\pm$	0.13	   	0.55	$\pm$	0.02	   	888	$\pm$	63	   	54	$\pm$	112

SDSSJ210831.56-063022.5	   	9253	$\pm$	1880	   	-0.24	$\pm$	0.05	   	0.28	$\pm$	0.03	   	-2613	$\pm$	481	   	-1618	$\pm$	452

SDSSJ212329.46-005052.9	   	6157	$\pm$	892	   	-0.06	$\pm$	0.05	   	0.40	$\pm$	0.01	   	-868	$\pm$	190	   	-635	$\pm$	396

SDSSJ235808.54+012507.2	   	7135	$\pm$	974	   	-0.14	$\pm$	0.03	   	0.40	$\pm$	0.01	   	-533	$\pm$	252	   	-55	$\pm$	443

Median     7135 $\pm$ 1888     -0.14 $\pm$ 0.20     0.40 $\pm$ 0.04     -392 $\pm$ 718     -55 $\pm$ 1134

6cPopulation B

SDSSJ114358.52+052444.9	   	7070	$\pm$	1027	   	-0.11	$\pm$	0.05	   	0.40	$\pm$	0.01	   	184	$\pm$	242	   	394	$\pm$	439

SDSSJ115954.33+201921.1	   	6813	$\pm$	1372	   	-0.12	$\pm$	0.07	   	0.34	$\pm$	0.01	   	257	$\pm$	396	   	644	$\pm$	378

SDSSJ120147.90+120630.2	   	5000	$\pm$	717	   	-0.18	$\pm$	0.20	   	0.34	$\pm$	0.04	   	667	$\pm$	156	   	609	$\pm$	315

SDSSJ153830.55+085517.0	   	5906	$\pm$	1222	   	-0.18	$\pm$	0.02	   	0.36	$\pm$	0.01	   	159	$\pm$	416	   	504	$\pm$	413

Median     6359 $\pm$ 1197     -0.15 $\pm$ 0.06     0.35 $\pm$ 0.03     220 $\pm$ 181     556 $\pm$ 141

§.§.§ SiIV$\lambda1397$+OIV]$\lambda1402$

Table <ref> presents the measurements on the full profile of SiIV$\lambda1397$+OIV]$\lambda1402$. We report values of FWHM (Col. 2), A.I. (Col. 3), kurtosis (Col. 4), $c$(1/2) (Col. 5), and c(9/10) (Col. 6). SiIV$\lambda1397$+OIV]$\lambda1402$ BC is set at rest-frame and our initial guess for this component takes into account the results obtained for the CIV$_{\rm{BC}}$ after fitting the CIV$\lambda$1549+HeII$\lambda$1640 region. SDSSJ141546.24+112943.4 has very strong and wide absorption lines in this region of the UV spectra, which makes it difficult to perform a reliable fitting (see Fig. <ref> in the Appendix <ref>).
Regarding the BLUE of SiIV$\lambda1397$+OIV]$\lambda1402$, they are very wide (even if apparently not as wide as in CIV$\lambda$1549+HeII$\lambda$1640), reaching more than 6000 km s$^{-1}$ in all cases, and representing a significant percentage of the full emission line profile. The shifts towards shorter wavelength are also smaller than for CIV$\lambda$1549, but they are still very high, going from 800 to 2700 km s$^{-1}$, with the extreme amplitude  of SDSSJ135831.78+050522.8 that reaches $\approx 4400$ km s$^{-1}$.

The fluxes of  and  presented in Table <ref> indicate that on average Pop. A presents higher values of the / ratio  ($\approx 0.69$) than Pop. B ($\approx 0.49$). This discrepancy may be linked to differences in chemical abundances with Pop. A sources being systematically more metal rich <cit.>.  However, the issue goes beyond the scope of the present work and will be discussed elsewhere.

§ DISCUSSION

In the previous section, we have shown that   Pop. A and Pop. B sources  may reflect  different contributions of line emitting gas that produces prominent blueshifted features and is most likely associated with an outflow.
To shed further  light on the role of outflows, we now report an interline comparison in both the optical and UV spectral regions. We highlight the effect of the outflowing components on the estimate of physical parameters such as black hole mass and Eddington ratio.

§.§ Defining the outflow

§.§.§ H$\beta$ and [OIII]$\lambda\lambda$4959,5007

Top panel: FWHM of the full profile of [OIII]$\lambda$5007 vs. FWHM of the full profile of H$\beta$. Bottom panel: Ratio $\delta_{\textrm{[O III]/H}\beta}=$ FWHM([OIII]$_{\rm full}$)/FWHM(H$\beta_{\rm full}$) vs. FWHM of the full profile of H$\beta$. As in Fig. <ref>, each colour represent one different spectral type, and symbols surrounded by open circles indicate the radio-loud quasars.

The relation between the FWHM of the full profiles of  and OIII]$\lambda$5007 is shown in Fig. <ref>. In general, the two populations present a FWHM(H$\beta_{\rm{full}}$) higher than FWHM([OIII]$_{\rm{full}}$), as expected from previous observations <cit.>. At low-z, only in the case of  the   “blue-outliers” the  profiles appear to be very boxy-shaped and with the FWHM $> 1000$ .  Some of these sources are NLSy1s  and the  FWHM is becoming comparable to the one of the broad  profile sources [Zamanov et al., 2002, Komossa et al., 2008, Cracco et al., 2016, Komossa et al., 2018, Berton & Järvelä, 2021]. At high $z$ and high luminosity the   profiles often appear much broader, as do also the  broad profiles [Carniani et al., 2015, Fiore et al., 2017, Villar Martín et al., 2020]. Two cases in point from previous works are 2QZJ002830.4-281706 at $z = 2.$ [Cano-Díaz et al., 2012, Carniani et al., 2015] and HE0940-1050 at $z = 3.1$ [Marziani et al., 2017].  We have four sources that present   FWHM above 3000 , comparable to the  FWHM, with   one extraordinary case in which FWHM(H$\beta_{\rm{full}}$) is smaller than FWHM([OIII]$_{\rm{full}}$) (SDSSJ135831.78+050522.8, Pop. A1), with FWHM(H$\beta_{\rm{full}}$) $\approx 3550$ km s$^{-1}$ and FWHM([OIII]$_{\rm{full}}$) $\approx 4320$ km s$^{-1}$ (see Fig. <ref>). Although FWHM of  $\gtrsim 2000$  are frequently observed at high luminosity, some extreme values should be taken with care because the  profiles are weak and broad:  it is  difficult to properly define the  profiles especially when the broad  red wing is strong.

Centroid velocity at 1/2 flux intensity ($c$(1/2)) of  vs. $c$(1/2) of . Blue and red open squares show the HE Pop. A and Pop. B sources studied by [Marziani et al., 2009] and [Sulentic et al., 2017]. Color scheme as in Fig. <ref>. The green line indicates the linear regression between $c$(1/2) of  and  obtained through the orthogonal least square method. The error bars refer to 1$\sigma$ level of confidence for our sample.

FWHM(H$\beta_{\rm{BC}}$) $vs.$ FWHM(CIV$_{\rm full}$)   and FWHM(H$\beta_{\mathrm{full}}$) $vs.$ FWHM(CIV$_{\rm full}$). Sources are identified according to the different bins of spectral types following color scheme from Fig. <ref>. Blue and red open squares represent Pop. A and Pop. B sources from [Sulentic et al., 2017] and grey and orange open squares indicate Pop. A and Pop. B from [Sulentic et al., 2007], respectively. Horizontal purple line indicates the A/B boundary and the error bars on the top left of the plots refer to 1$\sigma$ level of confidence for our sample.

§.§.§  vs. CIV$\lambda1549$

Fig. <ref> shows the relation between   $c$(1/2) for  and . The HE comparison sample analysed in [Marziani et al., 2009] and [Sulentic et al., 2017] is included. The sources that present strong shifts in the  emission line profiles will also present it in ,  in agreement with the HE data. Both lines show a correlation between their widths and shifts (Fig. <ref> for  and Fig. <ref> for ) indicating that the broadening is mainly associated with a blueshifted component that is increasing in prominence with increasing shift. The least squares linear regression of Fig. <ref> (considering both HEMS and our sample) is given by:

\begin{equation}
c(1/2)_{\rm \ion{C}{IV}}= (1.50 \pm 0.31)\  c(1/2)_{\rm [\ion{O}{III}]}+(-1239\pm 276),
\end{equation}

in a good agreement with the study of Coatman et al., 2019. The trend (actually, a weak, marginally significant correlation at a $3\sigma$ confidence level) of Fig. <ref> raises the issue of the relation between  and  outflows. There is evidence suggesting that the semi-broad component of  $W$ remains almost constant with luminosity <cit.>, overwhelming the narrow, core component. The narrow component is however mainly associated with the NLR that may extend up to tens of kpc [Bennert et al., 2002, Bennert et al., 2006]. The dispersion in the relation with more sources around 0 shift in  might be explained by a  narrow component whose strength may depend on the past AGN evolution [Storchi-Bergmann et al., 2018]. It is therefore not surprising that, even if a large  shift is measured, the  profile may be unshifted or show only a modest blueshift.  However, the presence of a shift correlation and the relatively large / FWHM ratio support  a physical connection between an inner outflow on scales of a few hundreds gravitational radii where the  BLUE   component is emitted, and an outflow at the outer edge of the BLR, beyond $10^4 - 10^5$ gravitational radii [Zamanov et al., 2002] where the  semibroad component likely originates.  The nature of this connection remains unclear.  It is beyond the scope of the present paper and might be investigated elsewhere.

§.§.§ CIV$\lambda1549$ versus

Top panel of Fig. <ref> represents the relation between   FWHM(H$\beta_{\rm BC}$) and FWHM(C IV$_{\rm full}$), including the [Sulentic et al., 2017]  sample. Our data is in agreement with this comparison sample in terms of a clear A/B separation.  Pop. A sources seem to present a trend from A1 to A3 in the FWHM(C IV$_{\rm full}$) where the A3 sources show the largest values.   The FWHM(C IV$_{\rm full}$) is larger than the FWHM(H$\beta_{\rm BC}$), and   the widths of the two lines are not correlated. There is a degeneracy between  and : to a single value of  FWHM corresponds a wide range of  FWHM . The systematically broader  profile  can be interpreted as a consequence of the dominance of the outflow component in the  line profile [Marziani et al., 2019].

The bottom panel of Fig. <ref> shows the FWHM(C IV$_{\rm full}$) vs. FWHM(H$\beta_{\rm full}$) where, apart from including [Sulentic et al., 2017] data, we also display the low-$z$ sample from [Sulentic et al., 2007] for comparison. In this plot, the separation between Pop. A and Pop. B is even clearer: Pop. A sources show broader , while those of Pop. B have values consistent with, or narrower, than .

CIV$_{\rm full}$ relation with . Colour scheme as in Fig. <ref>. The data points joined by a  dashed line are those for which a significant blueshifted emission component has been isolated. The left data points refer to the  BC only and the right ones (star symbol) to the full profile FWHM (BC+BLUE). Error bars refer to 1$\sigma$ level of confidence.

§.§.§ CIV$\lambda1549$ versus

Fig. <ref> shows FWHM of the full profiles of  vs. FWHM of . The FWHM(CIV$_{\rm full}$) presents significantly higher values than FWHM(AlIII).  This indicates that the relation between  and  is similar to  the one of  and . In both cases the  FWHM tends to be larger: always significantly so for Pop. A, and larger or consistent for Pop. B. The cyan and magenta dashed lines connect the FWHM estimated from the  BC with and without a BLUE component: without the BLUE (stars), the  FWHM becomes closer to,  but remains significantly smaller than the FWHM of the  full profile.

§.§ Virial black hole mass estimates