# BASS XXII: The BASS DR2 AGN Catalog and Data

Michael J. Koss Eureka Scientific, 2452 Delmer Street, Suite 100, Oakland, CA
94602-3017, USA  Space Science Institute, 4750 Walnut Street, Suite 205,
Boulder, CO 80301, USA  Claudio Ricci Núcleo de Astronomía de la Facultad de
Ingeniería, Universidad Diego Portales, Av. Ejército Libertador 441, Santiago
22, Chile  Kavli Institute for Astronomy and Astrophysics, Peking University,
Beijing 100871, People’s Republic of China  Benny Trakhtenbrot School of
Physics and Astronomy, Tel Aviv University, Tel Aviv 69978, Israel  Kyuseok Oh
Korea Astronomy & Space Science institute, 776, Daedeokdae-ro, Yuseong-gu,
Daejeon 34055, Republic of Korea  Department of Astronomy, Kyoto University,
Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan  JSPS Fellow  Jakob
S. den Brok Institute for Particle Physics and Astrophysics, ETH Zürich,
Wolfgang-Pauli-Strasse 27, CH-8093 Zürich, Switzerland  Argelander Institute
for Astronomy, Auf dem Hügel 71, D-53231, Bonn, Germany  Julian E. Mejía-
Restrepo European Southern Observatory, Casilla 19001, Santiago 19, Chile
Daniel Stern Jet Propulsion Laboratory, California Institute of Technology,
4800 Oak Grove Drive, MS 169-224, Pasadena, CA 91109, USA  George C. Privon
National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA
22903, USA  Department of Astronomy, University of Florida, P.O. Box 112055,
Gainesville, FL 32611, USA  Ezequiel Treister Instituto de Astrofísica,
Facultad de Física, Pontificia Universidad Católica de Chile, Casilla 306,
Santiago 22, Chile  Meredith C. Powell Kavli Institute of Particle
Astrophysics and Cosmology, Stanford University, 452 Lomita Mall, Stanford, CA
94305, USA  Richard Mushotzky Department of Astronomy, University of Maryland,
College Park, MD 20742, USA  Franz E. Bauer Instituto de Astrofísica and
Centro de Astroingeniería, Facultad de Física, Pontificia Universidad Católica
de Chile, Casilla 306, Santiago 22, Chile  Millennium Institute of
Astrophysics (MAS), Nuncio Monse$\sim$nor Sótero Sanz 100, Providencia,
Santiago, Chile  Space Science Institute, 4750 Walnut Street, Suite 205,
Boulder, Colorado 80301, USA  Tonima T. Ananna Department of Physics and
Astronomy, Dartmouth College, 6127 Wilder Laboratory, Hanover, NH 03755, USA
Mislav Baloković Yale Center for Astronomy & Astrophysics and Department of
Physics, Yale University, P.O. Box 208120, New Haven, CT 06520-8120, USA
Rudolf E. Bär Institute for Particle Physics and Astrophysics, ETH Zürich,
Wolfgang-Pauli-Strasse 27, CH-8093 Zürich, Switzerland  George Becker
Department of Physics & Astronomy, University of California, Riverside, CA
92521, USA  Patricia Bessiere Instituto de Astrofísica, Facultad de Física,
Pontificia Universidad Católica de Chile, Casilla 306, Santiago 22, Chile
Leonard Burtscher Leiden Observatory, P.O. Box 9513, 2300 RA, Leiden, the
Netherlands  Turgay Caglar Leiden Observatory, PO Box 9513, 2300 RA, Leiden,
the Netherlands  Enrico Congiu Departamento de Astronomía, Universidad de
Chile, Camino del Observatorio 1515, Las Condes, Santiago, Chile  Phil Evans
Department of Physics and Astronomy, University of Leicester, Leicester, LE1
7RH, UK  Fiona Harrison  Cahill Center for Astronomy and Astrophysics,
California Institute of Technology, Pasadena, CA 91125, USA  Marianne Heida
European Southern Observatory, Karl-Schwarzschild-Str. 2, D-85748 Garching bei
München, Germany  Kohei Ichikawa Frontier Research Institute for
Interdisciplinary Sciences, Tohoku University, Sendai 980-8578, Japan
Astronomical Institute, Graduate School of Science Tohoku University, 6-3
Aramaki, Aoba-ku, Sendai 980-8578, Japan  Max-Planck-Institut für
extraterrestrische Physik (MPE), Giessenbachstrasse 1, D-85748 Garching bei
Müunchen, Germany  Nikita Kamraj Cahill Center for Astronomy and Astrophysics,
California Institute of Technology, Pasadena, CA 91125, USA  Isabella Lamperti
Centro de Astrobiología (CAB), CSIC–INTA, Cra. de Ajalvir Km. 4, E-28850
Torrejón de Ardoz, Madrid, Spain  Fabio Pacucci Center for Astrophysics,
Harvard & Smithsonian, Cambridge, MA 02138, USA  Black Hole Initiative,
Harvard University, Cambridge, MA 02138, USA  Federica Ricci Instituto de
Astrofísica, Facultad de Física, Pontificia Universidad Católica de Chile,
Casilla 306, Santiago 22, Chile  Dipartimento di Fisica e Astronomia,
Università di Bologna, via Gobetti 93/2, 40129 Bologna, Italy  Rogério Riffel
Departamento de Astronomia, Instituto de Física, Universidade Federal do Rio
Grande do Sul, CP 15051, 91501-970, Porto Alegre, RS, Brazil  Alejandra F.
Rojas Centro de Astronomía (CITEVA), Universidad de Antofagasta, Avenida
Angamos 601, Antofagasta, Chile  Kevin Schawinski Modulos AG,
Technoparkstrasse 1, CH-8005 Zurich, Switzerland  Matthew Temple Universidad
Diego Portales, Av. Ejército Libertador 441, Santiago 8370109, Chile  C. Megan
Urry Yale Center for Astronomy & Astrophysics and Department of Physics, Yale
University, P.O. Box 208120, New Haven, CT 06520-8120, USA  Sylvain Veilleux
Department of Astronomy, University of Maryland, College Park, MD 20742, USA
Jonathan Williams Department of Astronomy, University of Maryland, College
Park, MD 20742, USA

(Accepted April 10, 2022)

###### Abstract

We present the AGN catalog and optical spectroscopy for the second data
release of the Swift BAT AGN Spectroscopic Survey (BASS DR2). With this DR2
release we provide 1449 optical spectra, of which 1182 are released for the
first time, for the 858 hard-X-ray-selected AGN in the Swift BAT 70-month
sample. The majority of the spectra (801/1449, 55%) are newly obtained from
Very Large Telescope (VLT)/X-shooter or Palomar/Doublespec. Many of the
spectra have both higher resolution (R${>}$2500, N$\sim$450) and/or very wide
wavelength coverage (3200-10000 Å, $N\sim$600) that are important for a
variety of AGN and host galaxy studies. We include newly revised AGN
counterparts for the full sample and review important issues for population
studies, with 47 AGN redshifts determined for the first time and 790 black
hole mass and accretion rate estimates. This release is spectroscopically
complete for all AGN (100%, 858/858) with 99.8% having redshift measurements
(857/858) and 96% completion in black hole mass estimates of unbeamed AGN
(722/752). This AGN sample represents a unique census of the brightest hard-X-
ray-selected AGN in the sky, spanning many orders of magnitude in Eddington
ratio ($L/L_{\rm Edd}$=$10^{-5}$–100), black hole mass ($M_{\rm
BH}$=$10^{5}{-}10^{10}$$M_{\odot}$), and AGN bolometric luminosity ($L_{\rm
bol}$=$10^{40}{-}10^{47}$${\rm\thinspace erg}{\rm\thinspace s}^{-1}\,$).

††journal: ApJS††facilities: Du Pont (Boller & Chivens spectrograph), Keck:I
(LRIS), Magellan:Clay, Hale (Doublespec), NuSTAR, Swift (XRT and BAT),
VLT:Kueyen (X-Shooter), VLT:Antu (FORS2), SOAR (Goodman)††software: Astropy
(Collaboration et al., 2013), ESO Reflex (Freudling et al., 2013), IRAF
(National Optical Astronomy Observatories, 1999), Matplotlib (Hunter, 2007),
molecfit (Smette et al., 2015), Numpy (van der Walt et al., 2011), Pandas
(https://doi.org/10.5281/zenodo.3630805), PySpecKit (Ginsburg & Mirocha, 2011)

##  1 Introduction

Many different optical spectroscopic surveys have been done of AGN in X-ray
survey fields. Early work focused on bright sources from the Einstein (e.g.
Stocke et al., 1991) and ROSAT surveys (e.g., Voges et al., 1999) typically
focused on obtaining basic redshift and counterpart information for tens to
hundreds of sources. This was later extended to deeper and fainter sources in
Chandra fields (e.g., Green et al., 2004; Szokoly et al., 2004; Eckart et al.,
2006; Treister et al., 2009; Silverman et al., 2010) or XMM-Newton surveys
(e.g., Menzel et al., 2016). Full spectroscopic completeness was difficult in
the deepest surveys owing to the optical faintness of distant targets (Brandt
& Hasinger, 2005). More recently, these efforts have focused on direct
estimates of supermassive black hole (SMBH) masses for X-ray-selected AGN with
broad emission lines using virial relations (e.g., Shen et al., 2011).

Larger optical spectroscopic samples of X-ray-selected active galactic nuclei
(AGN) now exist within the Sloan Digital Sky Survey (SDSS) footprint, though
typically focused on unobscured AGN. A total of 7005 ROSAT sources were cross-
matched with the SDSS spectroscopic footprint (Anderson et al., 2007). Due to
the soft X-ray sensitivity of ROSAT (e.g. 0.1–2.4 keV), the majority, 89%
(6224/7005), were broad-line AGN. Similarly, a study by Mahony et al. (2010)
in the southern hemisphere using spectra from the 6-degree-Field Galaxy Survey
(Jones et al., 2004, 2009), a near-infrared-selected redshift survey covering
a large area in the Southern hemisphere ($\sim$17000∘2), had spectroscopic
identifications for 1715 ROSAT sources in the Southern hemisphere. More
recently SPIDERS (SPectroscopic IDentification of eROSITA Sources, Dwelly et
al., 2017; Comparat et al., 2020) is currently collecting 40,000 spectra of
X-ray-selected AGN from ROSAT as well as the XMM slew survey (0.5–12 keV),
which is more sensitive to obscured AGN.

Hard X-ray emission ($>$10 keV) from the corona of the AGN can probe the
innermost parts of the central engine of AGN with the advantage over
UV/optical/soft X-rays that it can even find AGN in highly obscured (e.g.
$N_{\rm H}$$>10^{22}-10^{25}$ cm-2) systems. The Swift-BAT survey (Barthelmy
et al., 2005), with its all-sky coverage that is insensitive to obscuration up
to Compton-thick levels (Koss et al., 2016a), provides the largest, most
complete sample of bright, local ($z<0.1$), powerful AGN. The spectroscopic
coverage in the SDSS for BAT AGN, is, however, only $\sim$15% (Koss et al.,
2017). Therefore, a complete optical spectroscopic sample of BAT AGN,
including the unobscured to the highly obscured AGN which are largely absent
from ROSAT surveys, provides a unique way to fully understand BH growth and
its relation to the host galaxy. The BAT AGN survey also provides a bright
complement that is more sensitive to obscured AGN compared to the currently
ongoing eROSITA satellite mission and its all-sky survey (Predehl et al.,
2021).

The goal of the BAT AGN Spectroscopic Survey (BASS) is to provide the largest
available spectroscopic sample of Swift BAT ultrahard X-ray (14–195 keV)
detected AGN. In the BASS DR1 (Koss et al., 2017), mostly archival optical
telescope data was used for 641 BAT AGN from the 70-month BAT catalog
(Baumgartner et al., 2013) and 102 AGN comosing the NIR DR1 (Lamperti et al.,
2017). These data were then used in a variety of scientific studies, such as
between X-ray emission and high-ionization optical lines (Berney et al.,
2015), ionized gas outflows (Rojas et al., 2020), and radio emission (Baek et
al., 2019; Smith et al., 2020). Several works identified the importance of the
Eddington ratio in various scaling relations (e.g., Oh et al., 2017; Ricci et
al., 2017a, 2018) and links to host galaxy properties such as molecular gas
(Koss et al., 2021).

In the BASS data release 2 (DR2), we have identified all AGN among the 1210
sources in the BAT 70-month survey in order to obtain a 100% spectroscopically
complete sample of high-quality optical spectra and BH mass estimates for a
large fraction of AGN across the entire sky. High signal-to-noise ratio (S/N)
and spectral resolution optical spectroscopy with measurements of continuum,
emission and absorption lines, over the full optical range (3200-10000Å)
provides a large number of important diagnostics. To name a few, these include
star formation rates, stellar masses, stellar population ages, dust reddening,
metallicities, AGN-driven outflows, and dynamical properties of the galaxy
such as velocity dispersions of stellar populations (e.g., Tremonti et al.,
2004; Vazdekis et al., 2012; Yates et al., 2012; Shimizu et al., 2018; Rojas
et al., 2020). Repeat optical spectroscopy can also probe the time-variable
nature of these emission components such as in changing optical type AGN
(e.g., Collin-Souffrin et al., 1973; Shappee et al., 2014).

In this first catalog paper of the DR2 release series, we provide an updated
list of counterparts and the 1449 optical spectra of 858 AGN among the 1210
sources in the BAT 70-month survey (Baumgartner et al., 2013). We provide an
explanation of all the optical spectra obtained, their reductions, and general
derived measurements. An overview of the DR2 release and scientific results
and a comparison with other surveys are provided in Koss et al. (2022a).
Further catalogs of derived measurements will be provided in subsequent papers
such as broad-line measurements (Mejía-Restrepo et al., 2022), narrow
emission-line measurements from the best available optical spectra (Oh et al.,
2022), velocity dispersion measurements from stellar absorption lines (Koss et
al., 2022b), and the NIR spectroscopic measurements (Brok et al., 2022; Ricci
et al., 2022). We will also provide scientific investigations using DR2 data
such as the BH mass and Eddington ratio distribution function for obscured and
unobscured AGN Ananna et al. (2022), the ability of the MIR to recover
obscured AGN (Pfeifle et al., 2022), and the $M_{BH}$ \- $\sigma_{\star}$
relation of type 1 unobscured AGNs (Caglar, in prep.). Throughout this work,
we adopt $\Omega_{\rm M}{=}0.3$, $\Omega_{\Lambda}{=}0.7$, and
$H_{0}{=}70\,{\rm km\,s}^{-1}\,{\rm Mpc}^{-1}$. To determine extinction due to
Milky Way foreground dust, we use the maps of Schlegel et al. (1998) and the
extinction law derived by Cardelli et al. (1989) with $R_{v}$=3.1.

##  2 Revised AGN Catalog

The initial 70-month catalog (Baumgartner et al., 2013) was composed of 1210
sources, including 822 classified as AGN or associated with a galaxy and
likely an AGN, 287 Galactic sources (e.g., high/low-mass X-ray binary,
cataclysmic variable, pulsar), 19 clusters, and 82 unknown sources. The
counterpart positions and AGN classifications were updated based on WISE and
X-ray data for 838 AGN in the BASS DR1 Ricci et al. (see Appendix A, 2017b),
which included three dual AGN systems. However, even after the DR1, 44 unknown
BAT sources, typically near the Galactic plane ($\lvert
b\rvert{<}10^{\circ}$), had not been associated with counterparts. Here we
discuss the BASS DR2 AGN counterparts after an extensive examination of the
remaining unknown 70-month catalog sources and important issues for surveys of
these AGN.

Given the large (FWHM=19.5′) Swift BAT point spread function (PSF), it is
important to consider cases such as chance alignment of multiple AGN, AGN
clustering, and dual AGN for population studies. Due to the scarcity of Swift
BAT sources in the sky, the likelihood of chance alignment of any two
unassociated sources within the BAT beam is small. Specifically, there are
$\sim$850 sources at $\lvert b\rvert{>}5^{\circ}$, (91% of the sky), so the
likelihood of chance alignment of one unassociated source within the BAT beam
is very small, $\sim$0.2%. However, there are some unique cases involving
galaxy mergers (e.g., Koss et al., 2018) and galaxy clustering where multiple
AGN systems occur. Additionally, at lower fluxes, where AGN are more numerous,
there may be some cases of flux boosting where two sources below the sky
sensitivity both contribute to be above the detection sensitivity.

Throughout this work, we refer to AGN as Sy1 (with optical broad H$\beta$),
Sy1.9 (narrow H$\beta$ and broad H$\alpha$), and Sy 2 (with narrow H$\beta$
and narrow H$\alpha$, including small numbers of LINERs and AGN in
H2-dominated regions). This nomenclature is used for the sake of simplicity
and consistency with previous work, despite the fact that many of our BASS DR2
AGNs may not be considered as Seyfert galaxies, given their high (X-ray)
luminosities. Additionally, a small number of Sy2 sources would be better
classified as HII or LINERs or composites based on their position in the BPT
diagram (Koss et al., 2017) or even elusive AGN (Smith et al., 2014), due to a
lack of prominent lines. These classifications are discussed in detail in the
BASS DR2 paper on narrow emission-line measurements (Oh et al., 2022).
Finally, some Sy2 sources with narrow optical lines are known to have
polarized broad-lines or NIR broad-lines (e.g., Lamperti et al., 2017).

###  2.1 Newly Identified AGN and Galactic Sources

There were still some unidentified sources listed in the 70-month catalog,
typically within the Galactic plane, that were not part of the BASS DR1
sample. We examined them all to ensure that our sample provided a complete
census of all AGN detected with Swift BAT across the sky. Further optical
spectroscopy found many of them to be stellar in nature.

We uncovered an additional 22 AGN among the remaining unidentified sources
(Table 1). These sources were the brightest 2–10 keV sources within the 5′
Swift BAT position error circle, and optical spectroscopy confirmed their AGN
nature. The total sample then increases from 838 to 858 AGN.111838 AGN+22
newly identified-2 DR1 AGN found to be stellar Further details on the X-ray
modeling of these newly detected AGN will be provided in C. Ricci, et al.,
(2022 in preparation).

Table 1: New 70-month AGN Counterparts in BASS DR2

BAT ID | Swift Name | Counterpart | R.A. | Decl. | DR2 Type | $z$ | $b$ | $A_{V}$
---|---|---|---|---|---|---|---|---
(1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9)
25 | SWIFT J0041.0+2444 | SWIFT J004039.9+244539 | 10.1661783 | 24.7609374 | Sy1.9 | 0.078365 | -38.0 | 0.11
323 | SWIFT J0612.2-4645 | PMN J0612-4647 | 93.1121548 | -46.788457 | BZQ | 0.317767 | -25.8 | 0.17
343 | SWIFT J0640.0-4737 | SWIFT J064013.50-474132.9 | 100.056201 | -47.692985 | Sy2 | 0.057242 | -21.5 | 0.36
359 | SWIFT J0709.3-1527 | PKS 0706-15 | 107.302151 | -15.450997 | BZB | 0.142277 | -3.2 | 2.00
364 | SWIFT J0714.7-2521 | SWIFT J0714.7-2521 | 108.654098 | -25.290303 | Sy1 | 0.042503 | -6.5 | 1.62
367 | SWIFT J0723.8-0804 | 1RXS J072352.4-080623 | 110.971135 | -8.1039597 | Sy1.9 | 0.144926 | 3.4 | 0.94
396 | SWIFT J0755.4+8402 | 2MASS J07581638+8356362 | 119.571766 | 83.9435807 | Sy1 | 0.133952 | 28.7 | 0.15
410 | SWIFT J0812.3-4004 | 1RXS J081215.2-400336 | 123.058378 | -40.05667 | Sy1 | 0.074934 | -3.3 | 5.05
433 | SWIFT J0854.3-0827 | SWIFT J085429.35-082428.6 | 133.621953 | -8.4076316 | Sy2 | 0.188435 | 22.6 | 0.10
494 | SWIFT J1020.5-0237A | SDSS J102103.08-023642.6 | 155.262884 | -2.6118136 | Sy2 | 0.293645 | 43.1 | 0.13
516 | SWIFT J1045.3-6024 | 2MASS J10445192-6025115 | 161.216286 | -60.419879 | Sy2 | 0.047 aaThis particular AGN resides in a region of very high Galactic extinction ($A_{V}$=9.5), and the redshift is based on an He ii$\,\lambda 10830$ line measurement from the literature (Fortin et al., 2018). | -1.3 | 9.54
761 | SWIFT J1512.2-1053A | NVSS J151148-105023 | 227.952883 | -10.840131 | BZQ | 0.94672 | 39.0 | 0.34
780 | SWIFT J1548.1-6406 | SWIFT J1548.1-6406 | 237.1265671 | -64.0263441 | BZQ | 1.693124 | -7.6 | 0.64
897 | SWIFT J1737.7-5956A | 1RXS J173751.2-600408 | 264.466913 | -60.066598 | BZQ | 3.656025 | -14.8 | 0.23
1000 | SWIFT J1852.2+8424A | SWIFT J185024.2+842240 | 282.60455 | 84.3790556 | Sy1 | 0.183122 | 27.0 | 0.30
1001 | SWIFT J1852.2+8424B | 1RXS J184642.2+842506 | 281.707105 | 84.4181331 | Sy1 | 0.225381 | 27.1 | 0.30
1007 | SWIFT J1852.8+3002 | GALEXASC J185249.68+300425.8 | 283.206294 | 30.0741661 | Sy1.9 | 0.057301 | 12.9 | 0.62
1075 | SWIFT J2024.0-0246 | 1RXS J202400.8-024527 | 306.008863 | -2.7590708 | Sy1.9 | 0.137523 | -21.8 | 0.21
1083 | SWIFT J2034.0-0943 | 2MASX J20341926-0945586 | 308.5803195 | -9.7664501 | Sy2 | 0.081551 | -27.2 | 0.19
1091 | SWIFT J2048.4+3815 | 1RXS J204826.8+381120 | 312.112497 | 38.1903626 | Sy1 | 0.105394 | -3.4 | 2.76
1096 | SWIFT J2059.6+4301B | SWIFT J210001.06+430209.6 | 315.004153 | 43.036367 | Sy2 | 0.066023 | -2.0 | 4.09
1164 | SWIFT J2243.2-4539 | 2MASX J22422135-4539093 | 340.588956 | -45.652581 | Sy2 | 0.120675 | -58.4 | 0.03

Note. — A detailed description of this table’s contents is given in section 4.
Columns (1–2): BAT 70-month survey catalog ID and Swift name
(https://swift.gsfc.nasa.gov/results/bs70mon/). Column (3): corresponding
galaxy counterpart name in NED or SIMBAD based on the WISE positions. Columns
(4–5): right ascension and decl. of the IR counterpart of the BAT AGN, in
decimal degrees, based on WISE positions. Column (6): AGN type based on
optical spectroscopy–Sy1 (with broad H$\beta$), Sy1.9 (narrow H$\beta$ and
broad H$\alpha$), and Sy 2 (with narrow H$\beta$ and H$\alpha$). For beamed
AGN, the types include those with the presence of broad lines (BZQ), only host
galaxy features lacking broad lines (BZG), or traditional continuum-dominated
blazars with no emission lines or host galaxy features (BZB). Column (7): best
DR2 redshift measurement and the line or method used for the measurement.
Measurements are from a broad-line fitting code (Mejía-Restrepo et al., 2022),
when available for all Sy1 and BZQ sources with broad-line H$\beta$. For
narrow-line sources, the redshift is based on emission-line fitting of [O iii]
$\lambda 5007$, when possible. For some high Galactic extinction sources or
high-redshift sources $z{>}1$, other lines are used. Finally, host galaxy
templates are used for some continuum-dominated blazars (BZB) with no emission
lines. Column (8): Galactic latitude, in decimal degrees. (9) visual
extinction due to Milky Way foreground dust, using maps of Schlegel et al.
(1998) and the extinction law derived by Cardelli et al. (1989).

A summary of the 17 sources that are newly classified as Galactic is provided
in subsection 2.1. For 10/17 sources, we determine the stellar nature based on
optical spectroscopy, with the remaining sources being classified in recent
publications.

There are two cases that were thought to be AGN based on only an X-ray and
WISE detection in the BASS DR1, but optical follow-up (Figure 1) found the
source to be Galactic. SWIFT J0428.2-6704A, was found to be an eclipsing X-ray
binary (Kennedy et al., 2020) which follow-up optical spectra confirmed. We
observed SWIFT J1535.8-5749 (aka. IGR J15360-5750), but found the source
consistent with a very red star based on the Ca ii triplet spectral region
(8450–8700 Å) and CO-band heads (2.29-2.51 $\mu{\rm m}$).

Figure 1: Figure showing spectra of sources identified as Galactic based on
emission or absorption lines at redshift zero.

In the other 15 cases, the 70-month X-ray classification was uncertain
(Baumgartner et al., 2013), but the sources were found to be Galactic. For
instance, SWIFT J0630.9+1129, showed a very red star with H$\alpha$ emission
at $z{=}0$. SWIFT J1213.2-6020 (aka IGR J12134-6015) was found to be located
within 0$\farcs$3 of 2MASS J12132397-6015169 based on Chandra (Karasev et al.,
2012). The WISE and X-ray counterpart has a GAIA source within 1′′ with
$1.4\pm 0.055$ mas parallax, and a spectrum consistent with a star.

Table 2: New Galactic Sources in DR2

BATID | Counterpart | R.A. | Decl. | Telescope | $b$ | New Class | 70-month | Feature | Ref.
---|---|---|---|---|---|---|---|---|---
(1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10)
27 | CXOM31 J004232.0+411314 | 10.6336579 | 41.2206639 |  | -21.6 | Pulsar | in M31 |  | Y17
222 | SWIFT J042749.42-670436.1 | 66.9571685 | -67.076319 | VLT/X-shooter | -38.6 | Star |  | Broad H$\alpha$ | Ke20
289 | SWIFT J053457.91+282837.9 | 83.7412468 | 28.4770753 |  | -2.2 | CV | on plane |  | H18
336 | WISEA J063033.56+113414.1 | 97.63994 | 11.57063 |  | 0.8 | Star |  | Broad H$\alpha$ |
365 | 1RXS J071748.9-215306 | 109.4510999 | -21.88376786 |  | -4.3 | CV | in plane |  | H18
462 | SWIFT J092752.58-694438.8 | 141.979246 | -69.745714 |  | -13.5 | CV | SRC/X-RAY |  | H18
603 | 1RXS J121324.5-601458 | 183.3497138 | -60.2546853 | VLT/X-shooter | 2.3 | Star |  | Broad H$\alpha$ | Ka12
618 | XSSJ12270-4859 | 186.994503 | -48.895133 |  | 13.8 | Pulsar | CV? |  | D15
620 | 1RXS J123113.2-423524 | 187.80036 | -42.588943 | VLT/X-shooter | 20.1 | Star | X-ray src | Broad H$\alpha$ |
773 | IRAS15318-5740 | 234.011699 | -57.814826 | VLT/X-shooter | -1.7 | Star |  | Ca II Emission |
879 | 1RXS J172032.0-514414 | 260.135722 | -51.736956 | VLT/X-shooter | -8.3 | Star | SRC/X-RAY | Ca II Emission |
933 | IGR J17507-2856 | 267.6024 | -29.037 |  | -0.9 | LMXB | transient |  | L01
989 | SWIFT J183905.82-571507.6 | 279.774816 | -57.251419 | VLT/X-shooter | -21 | Star | SRC/X-RAY | Ca II Absorption |
993 | SWIFT J1842.2-1124 | 280.5729 | -11.4172 | Palomar/DBSP | -3.2 | LMXB | transient | Ca II Absorption | C16
1061 | SWIFT J200622.36+364140.9 | 301.591132 | 36.6982992 | Palomar/DBSP | 2.5 | CV | New src | Ca II Absorption | H18
1095 | SWIFT J205915.84+430109.5 | 314.815403 | 43.0189524 | Palomar/DBSP | -1.9 | HMXB | SRC/X-RAY | Ca II Absorption |
1159 | SWIFT J223703.9+632338 | 339.155838 | 63.492667 | Palomar/DBSP | 4.5 | CV | X-ray transient | Broad H$\alpha$ | H18

Note. — Column (1): BAT 70-month survey catalog ID. Column (2): corresponding
galaxy counterpart name in NED or SIMBAD based on the WISE positions. Column
(3–4): right ascension and decl. of the IR counterpart of the BAT AGN, in
decimal degrees, based on WISE positions. Column (5): telescope and instrument
used to observe the Galactic source. Column (6): Galactic latitude, in decimal
degrees. Column (7): Galactic classification based on reference or optical
spectral features. Star denotes stellar features in optical spectrum at
redshift zero, but uncertain classification. Column (8): initial
classification in 70-month catalog (Baumgartner et al., 2013). Column (9):
optical spectral feature used in redshift measurement. (10) References.

References. — C16: Corral-Santana et al. (2016); D15: de Martino et al.
(2015); H18: Halpern et al. (2018); Ka12: Karasev et al. (2012); Ke20: Kennedy
et al. (2020); L01: Liu et al. (2001); Y17: Yukita et al. (2017).

###  2.2 Excluded Unknown Sources in the Galactic Plane

The DR2 sample defined here is fully complete for all BAT 70-month BAT AGN and
unknown sources above ($\lvert b\rvert{>}3^{\circ}$) or below $A_{V}$=5 mag.
Beyond these limits an additional seven sources were excluded (Table 3) in the
analysis owing to their very high extinction values (5-43 $A_{V}$ mag).

Many of these sources have been surveyed extensively as part of INTEGRAL
surveys (e.g., Tomsick et al., 2008). These sources are very close to the
Galactic plane, with many foreground stars and very high extinction levels
that make any accurate optical targeting impractical, though they may host AGN
in some cases. A follow-up Chandra observation SWIFT J1848.5-0046 (aka IGR
J18485-0047) showed a source coincident with strong radio emission consistent
with an AGN (Tomsick et al., 2009). SWIFT J1403.6-6146 (aka IGR J14044-6146),
was observed with Chandra, but no detection was found after an earlier Swift
XRT detection, suggesting variability that may be associated with an AGN
(Bodaghee et al., 2012). In one case (SWIFT J2037.2+4151), optical spectral
follow-up showed a very red spectrum, but there was no obvious counterpart.
SWIFT J2056.8+4939 (aka 4C 49.35), has both radio emission and a likely Fermi
detection consistent with a blazar-like beamed AGN. None of the remaining
sources have been observed with Chandra, XMM-Newton, or NuSTAR. Further source
localization and characterization with Chandra, deeper X-ray observations with
XMM-Newton or NuSTAR, radio, and finally NIR spectroscopy will likely be
required to identify these sources and their possible AGN nature.

There was also one remaining 70-month transient source outside the Galactic
plane, SWIFT J0325.6-0907, which we exclude because it is likely a transient.
The source shows a declining significance in the 105-month light curve (Oh et
al., 2018), with a drop to zero XMM-Newton flux after 2010 January. A 10 ks
Swift XRT exposure finds no sources above $F^{\rm obs}_{\mathrm{2-10\ keV}}$
${=}10^{-13}$${\rm\thinspace erg}{\rm\thinspace cm}^{-2}{\rm\thinspace
s}^{-1}\,$in flux that could be a likely counterpart. No observations of this
source have been performed with Chandra, XMM-Newton, or NuSTAR.

Table 3: Unknown Sources at $\lvert b\rvert<3{\mbox{${}^{\circ}$}}$ and
$A_{V}$ Excluded from DR2

BAT ID | Swift Name | Counterpart | RA | DEC | $b$ | $A_{V}$
---|---|---|---|---|---|---
464 | SWIFT J0931.5-5105 | SWIFT J093118.1-510845 | 142.825292 | -51.146017 | 0.20 | 5.63
706 | SWIFT J1403.6-6146 | [CG2001] G311.45-0.13 | 211.12571 | -61.789482 | -0.13 | 43.08
742 | SWIFT J1447.0-5814 | SWIFT J144719.3-581616 | 221.831011 | -58.271689 | 1.24 | 7.42
1005 | SWIFT J1848.5-0046 | IGR J18485-0047 | 282.106051 | -0.7764179 | 0.32 | 35.98
1011 | SWIFT J1855.5+0516 | SWIFT J1855.5+0516 | 283.92069 | 5.220055 | 1.54 | 21.85
1086 | SWIFT J2037.2+4151 | SSTSL2 J203705.58+415005.3 | 309.273359 | 41.8347872 | 0.52 | 20.65
1094 | SWIFT J2056.8+4939 | RX J2056.6+4940 | 314.174892 | 49.6715329 | 2.76 | 9.25

Note. — Column descriptions are the same as in Table 1, unless otherwise
noted.

###  2.3 Dual AGN

In the case of bright dual AGN, both may contribute significantly to the BAT
flux (e.g. Koss et al., 2016b). Dual AGN are typically close together
($\sim<30$ kpc), show small offsets in redshift (${<}500$ ${\rm\thinspace
km}{\rm\thinspace s}^{-1}\,$), and often show signs of interaction in imaging.
For these sources, we report them as if they would have been individually
detected based on the sky sensitivity (Baumgartner et al., 2013), and report
the fluxes based on the soft X-ray emission (Ricci et al., 2017b). Additional
spectra of merging companions (e.g., Koss et al., 2010, 2012) will be
presented in a separate release (Koss, M., et al. 2022, in preparation).

A summary of bright dual AGN in the sample can be found in subsection 2.3.
This only includes dual AGN that are both X-ray detected, not lower-luminosity
AGN detected only in optical spectroscopy. The galaxy group Arp 318 (NGC
835/NGC 833) and the close dual AGN Mrk 463 are unique in that the sources are
individually below the median BAT sky sensitivity, but the combined flux is
above the median sky sensitivity. To be complete, we set the limit at $F^{\rm
obs}_{\mathrm{14-195\ keV}}$ ${>}5{\times}10^{-12}$ ${\rm\thinspace
erg}{\rm\thinspace cm}^{-2}{\rm\thinspace s}^{-1}\,$which corresponds to the
faintest detected sources in the sky by BAT rather than the median sensitivity
$F^{\rm obs}_{\mathrm{14-195\ keV}}$ ${>}1.03{\times}10^{-11}$ ${\rm\thinspace
erg}{\rm\thinspace cm}^{-2}{\rm\thinspace s}^{-1}\,$. We assume $F^{\rm
obs}_{\mathrm{14-195\ keV}}$ $\propto$ $F^{\rm in}_{\mathrm{2-10\ keV}}$ for
this calculation, and $\Gamma$=1.8, which is consistent at $N_{\rm
H}$${<}10^{23.5}$ cm-2 (Koss et al., 2016a; Ricci et al., 2018). This leads to
three sets of bright dual BAT-detected AGN in the DR2. See Ricci et al.
(2017b) and Koss et al. (2012) for a further discussion of these sources.

Table 4: Dual AGN in the DR2

BAT ID | Swift Name | Primary | Sec. | BAT Total | Ratio |  $F^{\rm obs}_{\mathrm{14-195\ keV}}$ Sec. | Incl. | Ref.
---|---|---|---|---|---|---|---|---
|  |  |  |  $10^{-12}$${\rm\thinspace erg}{\rm\thinspace cm}^{-2}{\rm\thinspace s}^{-1}\,$ |  |  $10^{-12}$${\rm\thinspace erg}{\rm\thinspace cm}^{-2}{\rm\thinspace s}^{-1}\,$ |  |
(1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9)
841 | SWIFT J1652.9+0223 | NGC6240S | NGC6240N | 72 | 0.32 | 23.0 | Y | P16
1077 | SWIFT J2028.5+2543 | MCG+04-48-002 | NGC 6921 | 78 | 0.20 | 15.6 | Y | K16
112 | SWIFT J0209.5-1010 | NGC 835 | NGC 833 | 15 | 0.46 | 7.1 | Y | O18
471 | SWIFT J0945.6-1420 | NGC 2992 | NGC 2993 | 27 | 0.14 | 3.8 | N | K12
703 | SWIFT J1355.9+1822 | Mrk 463E | Mrk 463W | 11 | 0.25 | 2.7 | N | K12
678 | SWIFT J1334.8-2328 | ESO 509-IG066W | ESO 509-IG066E | 18 | 0.10 | 1.8 | N | Ko17
176 | SWIFT J0324.9+4044 | IRAS 03219+4031 | 2MASXJ03251221+4042021 | 19 | 0.08 | 1.6 | N | K12
1198 | SWIFT J2328.9+0328 | NGC 7679 | NGC 7682 | 15 | 0.10 | 1.5 | N | K12
497 | SWIFT J1023.5+1952 | NGC 3227 | NGC 3226 | 109 | 0.01 | 1.1 | N | K12
552 | SWIFT J1136.0+2132 | Mrk 739E | Mrk 739W | 13 | 0.09 | 1.2 | N | K11

Note. — Columns (1–2): BAT 70-month survey catalog ID and Swift name
(https://swift.gsfc.nasa.gov/results/bs70mon/). Columns (3–4): primary and
secondary galaxy where the primary galaxy is the one with brighter soft X-ray
emission ($F^{\rm in}_{\mathrm{2-10\ keV}}$). Column (5): total hard X-ray
emission detected from BAT for both sources. Column (6): The ratio of the soft
X-ray emission of the secondary to the total emission based on intrinsic soft
X-ray emission ($F^{\rm in}_{\mathrm{2-10\ keV}}$). Column (7): the predicted
$F^{\rm obs}_{\mathrm{14-195\ keV}}$ for the secondary given the soft X-ray
emission. Column (8): whether or not the secondary galaxy optical spectra is
included in the DR2 release. Column (9): references.

References. — Ko17: Kosec et al. (2017); K11: Koss et al. (2011); K12: Koss et
al. (2012). O18: Oda et al. (2018); P16: Puccetti et al. (2016).

###  2.4 Weakly Associated AGN

Previous studies have also found that galaxy clustering is higher around BAT
AGN (e.g., Cappelluti et al., 2010; Koss et al., 2010) and this extends to
secondary nearby AGN on scales of 70-1000 kpc. These AGN will be separated by
significant distances on the sky of several arcminutes, but show small offsets
in redshift (${<}500$ ${\rm\thinspace km}{\rm\thinspace s}^{-1}\,$) and can
often be found with several other galaxies clustering at the same redshift.
These two AGN will reside in the BAT beam and may both be bright enough to be
individually detected. In other cases, the clustered AGN would not be
individually detected, but they are detected by BAT because of flux boosting.
See subsection 2.4 for further details on these systems.

Here we provide a list of multiple soft X-ray AGN that are detected within the
BAT beam but are weakly associated ($\sim$70-700 kpc; Table 5). This includes
seven pairs of AGN. In three cases (SWIFT J0202.4+6824B, SWIFT J0359.0-3015A,
SWIFT J1051.2-1704B), one of the AGN is below the median BAT sky sensitivity
and should be excluded from population studies.

Table 5: Weakly Associated Counterparts in DR2

BAT ID | Swift ID | R.A. | Decl. | Counterpart | DR2 Type | $z$ | $F^{\rm obs}_{\mathrm{14-195\ keV}}$ | OffsetaaOffset between two BAT AGN in measured redshift (${\rm\thinspace km}{\rm\thinspace s}^{-1}\,$) and WISE position (′′ and kpc) at the redshift of the first AGN listed. |  |
---|---|---|---|---|---|---|---|---|---|---
|  |  |  |  |  |  | ($10^{-12}$${\rm\thinspace erg}{\rm\thinspace cm}^{-2}{\rm\thinspace s}^{-1}\,$ ) | (${\rm\thinspace km}{\rm\thinspace s}^{-1}\,$) | (′′) | (kpc)
103 | SWIFT J0202.4+6824A | 30.5723165 | 68.3626549 | LEDA89913 | Sy2 | 0.011836 | 11.53 | 58 | 294 | 72
104 | SWIFT J0202.4+6824B | 30.384773 | 68.4060751 | LEDA137972 | Sy1.9 | 0.012028 | 7.68 |  |  |
202 | SWIFT J0359.0-3015A | 59.8354003 | -30.20269 | SARS059.33488-30.34397 | Sy1.9 | 0.097452 | 8.42 | 1086 | 391 | 681
203 | SWIFT J0359.0-3015B | 59.7867976 | -30.302943 | SARS059.28692-30.44439 | Sy2 | 0.093833 | 10.98 |  |  |
520 | SWIFT J1051.2-1704A | 162.812665 | -17.008078 | NGC3431 | Sy2 | 0.01744 | 22.43 | 337 | 529 | 188
521 | SWIFT J1051.2-1704B | 162.9061 | -17.124721 | LEDA32573 | Sy2 | 0.018563 | 3.72 |  |  |
657 | SWIFT J1306.4-4025A | 196.608846 | -40.41461 | ESO323-77 | Sy1.5 | 0.01563 | 33.06 | 171 | 525 | 168
658 | SWIFT J1306.4-4025B | 196.800383 | -40.407563 | ESO323-81 | Sy1 | 0.0162 | 16.91 |  |  |
746 | SWIFT J1451.0-5540A | 222.888099 | -55.677311 | LEDA3079667 | Sy1.9 | 0.018091 | 40.84 | 172 | 1216 | 461
747 | SWIFT J1451.0-5540B | 222.303112 | -55.605703 | LEDA3085605 | Sy2 | 0.018663 | 26.5 |  |  |
754 | SWIFT J1506.7+0353A | 226.485635 | 3.7073107 | Mrk1392 | Sy1.5 | 0.036009 | 19.01 | 375 | 905 | 648
755 | SWIFT J1506.7+0353B | 226.684 | 3.862 | 2MASXJ15064412+0351444 | Sy2 | 0.037259 | 15.67 |  |  |
1173 | SWIFT J2254.2+1147A | 343.681327 | 11.7141072 | UGC12243 | Sy2 | 0.028508 | 12.55 | 88 | 428 | 245
1174 | SWIFT J2254.2+1147B | 343.581956 | 11.7825716 | UGC12237 | Sy2 | 0.028215 | 17.11 |  |  |

Note. — Column descriptions are the same as in Table 1, unless otherwise
noted.

###  2.5 Multiple Unassociated Faint X-Ray Counterparts

Some sources in the initial 70-month catalog were reported with multiple
likely counterparts within the error circle of the BAT beam position
(Baumgartner et al., 2013). The details of many of these sources and their
fluxes were described further in Ricci et al. (2017b) as part of the BASS DR1.
Sources below the median sky sensitivity ($F^{\rm obs}_{\mathrm{14-195\ keV}}$
${<}10.3{\times}10^{-12}$ ${\rm\thinspace erg}{\rm\thinspace
cm}^{-2}{\rm\thinspace s}^{-1}\,$) should be excluded from population studies
based on the all-sky sensitivity because they were likely detected only
because of X-ray follow-up (Table 6). Among these, 10 pairs of sources 76%
(20/26) are cases of flux boosting that individually are below the median
sensitivity. Another six cases are fainter counterparts to a brighter BAT
source that is above the median detection sensitivity. There is only one case
of a pair of AGN with both AGN above the detection sensitivity (SWIFT
J1652.0-5915) which includes NGC 6221 ($z{=}0.0041$) and the background galaxy
ESO 138-1 ($z{=}0.0091$).

Table 6: Faint Soft X-Ray Counterparts in DR2

BAT ID | Swift ID | R.A. | Decl. | Counterpart | DR2 Type | $z$ |  $F^{\rm obs}_{\mathrm{14-150\ keV}}$ ($10^{-12}$${\rm\thinspace erg}{\rm\thinspace s}^{-1}\,$)
---|---|---|---|---|---|---|---
29 | SWIFT J0042.9+3016A | 10.7578514 | 30.2887771 | 2MASXJ00430184+3017195 | Sy2 | 0.04894 | 7.72
92 | SWIFT J0149.2+2153A | 27.2487096 | 21.7594329 | LEDA1656658 | Sy1.9 | 0.069397 | 8.69
93 | SWIFT J0149.2+2153B | 27.353505 | 21.9973509 | NGC678 | Sy2 | 0.009485 | 8.17
223 | SWIFT J0428.2-6704B | 67.4475784 | -67.055521 | 2MASXJ04294735-6703205 | Sy1.2 | 0.064848 | 3.21
320 | SWIFT J0609.5-6245A | 92.5272683 | -62.720088 | 2MASXJ06100652-6243125 | Sy1 | 0.157475 | 9.45
321 | SWIFT J0609.5-6245B | 92.1613084 | -62.787855 | LEDA2816519 | Sy1 | 0.099173 | 3.88
494 | SWIFT J1020.5-0237A | 155.262884 | -2.6118136 | SDSSJ102103.08-023642.6 | Sy2 | 0.293645 | 6.88
495 | SWIFT J1020.5-0237B | 154.994136 | -2.5767385 | SDSSJ101958.58-023436.2 | Sy1 | 0.059739 | 5.93
528 | SWIFT J1105.7+5854A | 166.495981 | 58.9460474 | Z291-28 | Sy2 | 0.047752 | 5.89
529 | SWIFT J1105.7+5854B | 166.406764 | 58.8557915 | 2MASXJ11053754+5851206 | Sy1.2 | 0.191213 | 5.34
550 | SWIFT J1132.9+1019B | 173.247877 | 10.395067 | [HB89]1130+106 | BZQ | 0.539603 | 8.78
554 | SWIFT J1138.9+2529A | 174.640356 | 25.3981165 | LEDA1735060 | Sy2 | 0.025363 | 8.94
555 | SWIFT J1138.9+2529B | 174.813041 | 25.5993964 | SDSSJ113915.13+253557.9 | Sy2 | 0.21925 | 5.63
601 | SWIFT J1213.1+3239B | 183.265867 | 32.7935448 | B21210+33 | BZQ | 2.50706 | 8.12
632 | SWIFT J1240.2+3457A | 189.96528 | 34.9749458 | Mrk653 | Sy2 | 0.042812 | 9.00
633 | SWIFT J1240.2+3457B | 190.435624 | 35.0627157 | NGC4619 | Sy1.9 | 0.022946 | 7.02
664 | SWIFT J1313.6+3650A | 198.453989 | 36.8994443 | RXJ1313.8+3653 | Sy1.5 | 0.066945 | 7.12
665 | SWIFT J1313.6+3650B | 198.364486 | 36.5938771 | NGC5033 | Sy1.9 | 0.002763 | 5.52
761 | SWIFT J1512.2-1053A | 227.952883 | -10.840131 | NVSS J151148-105023 | BZQ | 0.94672 | 5.97
762 | SWIFT J1512.2-1053B | 228.021112 | -10.776578 | 2MASXJ15120505-1046356 | Sy2 | 0.165799 | 8.31
897 | SWIFT J1737.7-5956A | 264.466913 | -60.066598 | 1RXSJ173751.2-600408 | BZQ | 3.656025 | 2.18
924 | SWIFT J1747.8+6837A | 267.159564 | 68.7045251 | Mrk507 | Sy1.2 | 0.055038 | 4.83
925 | SWIFT J1747.8+6837B | 266.748141 | 68.6085193 | 2MASS J17465953+6836303 | Sy1.2 | 0.063785 | 5.23
1000 | SWIFT J1852.2+8424A | 282.60455 | 84.3790556 | SWIFT J185024.2+842240 | Sy1 | 0.183122 | 5.51
1001 | SWIFT J1852.2+8424B | 281.707105 | 84.4181331 | 1RXSJ184642.2+842506 | Sy1 | 0.225381 | 4.19
1096 | SWIFT J2059.6+4301B | 315.004153 | 43.036367 | SWIFT J210001.06+430209.6 | Sy2 | 0.066023 | 5.84

Note. — Column descriptions are the same as in Table 1.

###  2.6 Beamed and Lensed AGN

The Swift BAT survey includes beamed, lensed, and unbeamed AGN and it is
important to separate them in most scientific analyses. The original DR1
included 105 beamed sources (see, e.g., Table 1 of Ricci et al., 2017b), based
on the Roma Blazar Catalog (BZCAT) catalog (Massaro et al., 2009) and DR1
optical spectra (Koss et al., 2017). Since this release, a further study by
Paliya et al. (2019) used recent Fermi LAT data and SED fitting to identify
all the blazars in the 105-month catalog, which includes all DR2 70-month AGN.

For continuity, we provide all of the new beamed AGN, or changes of beamed AGN
from the DR1 classifications to unbeamed in DR2 or vice versa, in subsection
A.1 in subsection A.1. In most cases, recent radio observations or SED fitting
(Paliya et al., 2019) revealed beamed AGN to be unbeamed, or conversely, a
recent Fermi detection revealed a previously categorized unbeamed AGN to be
beamed. In DR2, 13/105 (12%) changed from beamed to unbeamed AGN
classification. Conversely, eight unbeamed AGN in the DR1 list were found to
be beamed. Finally, five beamed AGN were included because they are part of the
expanded list of AGN, that were not in the original list of 838 DR1 AGN.

For DR2, we reviewed all the beamed classifications and found three AGN that
were classified as beamed AGN in (Paliya et al., 2019), but we now classify
them as unbeamed AGN based on further analysis. SWIFT J0312.9+4121 (aka QSO
B0309+411), while detected in Fermi, is a broad-line radio galaxy, with
double-lobe morphology within a compact structure (Tzanetakis et al., 1978).
For SWIFT J0519.5-3140 (aka PKS 0521-365), Angioni et al. (2019) found with
VLBI imaging that the jet of PKS 0521-36 is not highly beamed, with viewing
angles larger than 10∘. Finally, SWIFT J1742.1-6054 (aka PKS1737-60), was
classified as an FRII radio galaxy (Bassani et al., 2016). Further
polarimetric observations or detections of compact cores and superluminal
motions using high-resolution radio imaging would be needed to further
classify these sources.

The beamed DR2 AGN then total 105, the same as in the DR1 despite the 26
changes. There is also a lensed AGN, SWIFT J1131.9-1233 (aka QSO J1131-1231 at
$z{=}0.654$) by a galaxy at $z{=}0.295$ (Berghea et al., 2017; Sluse et al.,
2017). Finally, SWIFT J1833.7-2105 (aka PKS 1830-211 at $z{=}2.5$) is both
beamed and also lensed (Lidman et al., 1999) by a foreground spiral at
$z{=}0.89$ (Winn et al., 2002).

Table 7: DR2 Instrument Setups

Telescope | Instrument | Total | Grating | Range | Dispersion | Slit Width | Res. | $R$ | LSF
---|---|---|---|---|---|---|---|---|---
|  |  | (lines/mm) | (Å) | (Ang/pix) | (′′) | FWHM (Å) |  | Type
(1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10)
Palomar | Doublespec | 440 | 600/316 | 3150-5598/5200-10500 | 1.07/1.54 | 1.5 | 4.1/4.9 | 1220/1730 | Stars/molecfit
|  | 33 |  |  |  | 2 | 4.8/6.5 | 1040/1290 | Sky lines/molecfit
|  | 2 |  |  |  | 1 | 3/3.6 | 1670/2360 | Sky lines/molecfit
|  | 1 |  |  |  | 0.5 | 2.6/3.2 | 1920/2660 | Sky lines/molecfit
|  | 10 | 300/316 | 3413-5500:4760-10500 | 1.07/1.54 | 1.5 | 8.1/4.9 | 620/1730 | Sky lines/molecfit
|  | 10 | 600/600 | 3150-5598/5570-8930 | 1.07/0.82 | 2 | 4.8/3.4 | 1040/2500 | Sky lines/molecfit
|  | 6 |  |  |  | 1.5 | 4.1/2.8 | 1220/3030 | Sky lines/molecfit
|  | 51 | 1200/1200 | 3970-5499/8050-9600 | 0.55/0.4 | 2 | 2.3/1.8 | 2170/4720 | Sky lines/molecfit
|  | 15 |  |  |  | 1.5 | 2/1.3 | 2500/6000 | Sky lines/molecfit
VLT | X-shooter | 179 | Echelle | 2990-5560/5337-10200 | 0.2 | 1.6/1.5 | 1.3/1.4 | 3850/6000 | Stars/molecfit
|  | 11 |  |  |  | 1/0.9 | 0.9/1.0 | 5500/8900 | Arc lines
|  | 4 |  |  |  | 1.3/1.2 | 1.2/1.3 | 4120/6500 | Arc lines
|  | 2 |  |  |  | 1/1.2 | 0.9/1.3 | 5500/6500 | Arc lines
|  | 1 |  |  |  | 0.8/0.7 | 0.8/0.7 | 6650/11570 | Arc lines/Stars
|  | 36 | IFU |  |  | 1.8 | 1/0.6 | 8600/13330 | Sky lines
| FORS2 | 61 | 600 | 3400-6100 | 1.32 | 1 | 6 | 830 | Sky lines
|  | 9 | 300 | 6100-11000 | 2.8 |  | 6.8 | 1250 | Sky lines
| MUSE | 4 |  | 4800-9300 | 1.25 | 2 | 2.7/2.7 | 1850/3150 | Instrument
|  | 2 |  |  |  | 1 | 2.7/2.7 | 1850/3150 | Instrument
SOAR | Goodman | 58 | 400 | 4560-8690 | 0.99/1.98 | 1.2 | 5.6/5.2 | 890/1630 | Stars
|  | 9 | 600 | 5290-7200 | 1.29 | 1.2 | 3.8 | 1450 | Sky lines
|  | 34 | 931 | 8000-9600 | 0.39/0.78 | 1.2 | 2.7 | 3150 | molecfit
|  | 50 | 1200 | 7900-9070 | 0.28 | 1.2 | 1.8 | 4720 | molecfit
|  | 2 |  |  |  | 0.45 | 0.7 | 12100 | molecfit
APO | SDSS | 146 | Fiber | 3830-9180 | 1.15/1.96 | 3 | 3.0/4.1 | 1760/2490 | Survey
|  | 31 |  | 3600-10330 |  | 2 | 2.9/3.4 | 1650/2070 | Survey
Dupont | BC | 119 | 300 | 3000-9070 |  | 1 | 10.4 | 480 | Stars
Keck | LRIS | 15 | 600/400 | 3200-5600/5450-10280 | 1.23/1.19 | 1 | 3.9/4.7 | 1280/1810 | Sky lines/molecfit
|  | 4 |  |  |  | 1.5 | 4.6/6.3 | 1090/1490 | Sky lines/molecfit
|  | 1 | 600/600 |  | 1.23/0.8 | 1.5 | 4.6/5.4 | 1090/1670 | Sky lines/molecfit
|  | 1 | 600/1200 |  | 0.61/0.4 | 1 | 3.9/1.6 | 1280/5310 | Sky lines/molecfit
Magellan | MAGE | 12 | Echelle | 3300-10010 | 0.25 | 1 | 1.3 | 3850 | Sky lines

Note. — See section 4 for a detailed description of this table’s contents.
Column (1): telescope. Column (2): instrument. Column (3): total number of DR2
spectra observed with this setup. Column (4): grating listing the lines/mm, if
applicable. For instruments with a blue and red side two numbers are listed
associated with each grating. Columns (5–9): wavelength range (Range), pixel
dispersion, resolution (Res.), and resolving power ($R$). These represent
typical values for this setup and may have small differences within individual
spectra depending on observing conditions. These quantities may also be
wavelength dependent in some cases, and so the values are given at 5000 Å and
8500 Å depending on the spectral range. Two values are listed when the
instrument had both a blue and red arm with different settings. Column (10):
method used to determine the instrumental resolution, either with sky lines,
telluric features with molecfit, with arc lines, fitting stellar templates to
stars, or based on resolutions provided within the survey (e.g. SDSS). The
measurements are for 5000 or 8500 Å or both depending on the spectral range.
See subsection 3.4 for further details.

##  3 Survey, Observations, and Data Reduction

Here we provide an overview of DR2 survey and observations. The DR2 targeting
criteria goals were to provide the largest possible sample of BH mass
measurements from either broad Balmer lines or stellar velocity dispersion
measurements, as well as the broadest possible spectral coverage (e.g.
3000–10000 Å) for emission-line measurements for the entire catalog of 858
AGN. In practice, outside of echelle instruments, this required multiple
spectra with broad wavelength coverage with lower-resolution or higher-
resolution gratings with narrower wavelength coverage. Repeat observations
were done if the S/N of the broad Balmer lines (H$\beta$ or H$\alpha$) was too
low for measurements (Mejía-Restrepo et al., 2022) or the low S/N and/or
spectral resolution of the stellar absorption features resulted in a failed
measurement of velocity dispersion. We did not reobserve targets with
acceptable spectra and measurements from the SDSS. The requirement for high
S/N, high spectral resolution, and broad wavelength coverage, combined with
queue mode observing approved months in advance, sometimes resulted in
duplicate (or more) observations of the same source. Example spectra for
different instrumental setups are provided in Appendix B. All spectra
associated with DR2 for each AGN will be provided at the BASS
website.222https://www.bass-survey.com/

A summary of all the observational setups used is shown in Table 7. We did not
specifically exclude sources with high Galactic extinction in spectroscopic
targeting if there was an obvious optical counterpart to the WISE counterpart
of the soft X-ray emission. This resulted in observations of 12 AGN with very
high extinctions (between $A_{V}$=5 and 10 mag) close to the Galactic plane
($0<b<3^{\circ}$), primarily to determine the first redshift and AGN type.

The data reduction and analysis of DR2 spectra maintain the uniform approach
described in the initial DR1 paper (Koss et al., 2017). All new spectra are
processed using the standard tasks for cosmic-ray removal, 1D spectral
extraction, wavelength, and flux calibrations, in either IRAF or the
ESO/Reflex environment for the Very Large Telescope (VLT) instruments. The
spectra are flux-calibrated using standard stars, which were typically
observed two to three times per night. The spectra are corrected for Galactic
reddening. Finally, a telluric absorption correction is applied to the spectra
with the software molecfit.

###  3.1 Master Observing Table

Table 8: Column Description for the Master Observing Table.

Column | Name | Units
---|---|---
1 | BAT_ID |
2 | Telescope |
3 | Diameter | m
4 | Instrument |
5 | File |
6 | File Red |
7 | Flags |
8 | Date |
9 | Range | Å
10 | Grating |
11 | Grating Red |
12 | $R$ |
13 |  $R$ Red |
14 | Res | Å
15 | Res Red | Å
16 | Slit Width | ′′
17 | Slit Width Red | ′′
18 | Slit Length | ′′
19 | Slit Length Red | ′′
20 | Angle | ∘
21 | Seeing | ′′
22 | Air mass |
23 | Exposure | s
24 | CDELT | Å/pix
25 | CDELT Red | Å/pix
26 | BC | ${\rm\thinspace km}{\rm\thinspace s}^{-1}\,$
27 | EBV | mag

Note. — See subsection 3.1 for detailed descriptions of each field.

We provide the following key parameters when possible for each individual
spectrum (Table 8):

  1. 1.

BAT ID: Catalog ID in the BAT
survey.333https://swift.gsfc.nasa.gov/results/bs70mon/

  2. 2.

Telescope, diameter, instrument: Name of observatory, its diameter, and
instrument used.

  3. 3.

File and File red: Name of associated fits spectral file. For telescopes with
both a blue and red side, two spectra are listed.

  4. 4.

Flags: Any associated flags with calibration or spectral extraction. Star:
indicates foreground stellar contamination, that a very nearby star (${<}2$
′′) contributed to the emission despite a very small extraction region. Red:
indicates that only the red side is extracted because the Galactic extinction
was so high (e.g. $A_{V}{>}$3) that no source is detected in the blue.
Calibration: indicates that the object was observed under poor conditions or
the standard star was observed on a different night, so spectral calibration
may be more uncertain than usual. Tellurics: indicates that the spectrum
suffers from worse-than-usual telluric correction or that the molecfit
correction was unsuccessful. Shortblue: the setup has a shorter than normal
blue wavelength coverage due to a reduction issue.

  5. 5.

Date: UT date of observation.

  6. 6.

Spectral Range: Range of the spectra in Å. For telescopes with both a blue and
red side, two spectral ranges are listed with the blue side first.

  7. 7.

Grating: Name of associated grating or grism. If the instrument had both a
blue (shorter wavelength) and red camera (longer wavelength), two gratings are
listed with the blue side listed first.

  8. 8.

R and Res FWHM: Instrumental resolution and FWHM in Å. For telescopes with
both a blue and red side, two numbers are provided with the blue side first.

  9. 9.

Slit: Slit width in ′′. For telescopes with both a blue and red side, two
widths are listed with the blue side first.

  10. 10.

Slit length: Extraction length along the slit in ′′. For telescopes with both
a blue and red side, two lengths are listed with the blue side first. If
multiple exposures were combined with optimal extraction (e.g. Palomar/DBSP),
the average value is listed.

  11. 11.

Angle: Position angle in degrees, measured east of north. In most cases the
sources were observed at parallactic unless a nearby galaxy was observed in
the same slit.

  12. 12.

Seeing: Recorded seeing of observations. When possible we use the average
seeing. We have not corrected the seeing observations to the observed air
mass.

  13. 13.

Exposure: Total exposure from all combined observations for the individual
spectra.

  14. 14.

CDELT: Pixel dispersion in Åper pixel. For telescopes with both a blue and red
side, two widths are listed with the blue side first. Only included for
spectra with linear dispersions (e.g. not the SDSS).

  15. 15.

Airmass: Average air mass during observation.

  16. 16.

BC: Barycenter correction ${\rm\thinspace km}{\rm\thinspace s}^{-1}\,$needed
for the Earth’s motion based on observation time and observatory location. The
computed correction should be added to any observed velocity to determine the
final barycentric radial velocity. As this correction is small (e.g. $<30$
${\rm\thinspace km}{\rm\thinspace s}^{-1}\,$), it has not been applied to any
catalog measurements in the DR2.

  17. 17.

EBV: Atmospheric extinction.

We note that all of these observing parameters are not available for every
spectrum, including most of the archival sample, but we provide them when
possible.

###  3.2 Overview of Samples

Here we provide a list of the telescopes used and their respective data
reductions. A plot of the number of spectra from each telescope is provided
(Figure 2) as well as summary plots of typical observing conditions and
resolution (Figure 3). The redshift range of observations can be found in
Figure 4.

Figure 2: Horizontal bar chart showing the number of spectra taken with each
telescope, instrument, or survey. The archival sample is from earlier surveys
that were not included in the DR1, including ROSAT AGN that overlap with BASS
in unpublished or published (Grupe et al., 2004) works, from the Palermo
surveys of Swift BAT AGN (Rojas et al., 2017), or as part of an atlas of low-
redshift AGN (Ho & Kim, 2009).

Figure 3: Summary of the different observing conditions for DR2 spectra for
telescopes with more than 15 spectra. Observing dates are shown for the newly
observed sample (top left) and archival sample (top right). The spectral
resolution at 5000 Å (middle left) and 8500 Å (middle right) for the different
observations. Finally, the seeing and average air mass of the observations
(bottom row).

Figure 4: Redshift range of all the AGN in the sample, split into unbeamed
(upper left) and beamed AGN (upper right). Additionally, the lower panel shows
the slit width size in kpc for all the unbeamed AGN.

####  3.2.1 Palomar Telescope

The largest sample of targeted sources, 402, was observed with the Palomar
Double Spectrograph (DBSP) on the 200-inch Hale telescope. These AGN were
observed as part of a dedicated program on BAT AGN (P.I. M. Urry or M. Powell)
or as part of the NuSTAR program (P.I. F. Harrison and D. Stern), where they
served as backup targets to faint NuSTAR serendipitous sources. The
observations were performed between 2012 October and 2020 November. The
majority of observations were taken with the D55 dichroic, with the 600/4000
and 316/7500 gratings using a 1$\farcs$5 slit, This setup provided resolutions
of $\sim$4.4 Å and $\sim$5.8 Å FWHM, over the $\sim$3150–5650 Å (blue) and
$\sim$5400–10500 Å (red) region, respectively, providing full spectroscopic
coverage of the optical region. The size of the aperture used for extraction
along the slit depended on the specific observing run, but was either fixed at
1.5-2′′or matched to the extended profile of the source in the IRAF APALL
task. We note that there are some flux calibration issues at some of the
grating edges due to loss of sensitivity specifically at 5400–5650 Å on the
blue side and 5400–5600 Å on the red side and at 10000–10500 Å (see examples
in Appendix B). In some cases, the region between 5400 and 5650 Å was not
extracted. Also, we did not force the spectra to be flux-calibrated in the
overlapping regions, and differences of 10-20% in flux may occur between the
blue and red sides.

A smaller set of 66 narrow-line AGN and Sy1.9 AGN were also observed using the
higher-resolution 1200 lines/mm grating for higher spectral resolution
velocity dispersion measurements of the 3960–5500 Å and 8150–9600 Å regions,
respectively.

####  3.2.2 Very Large Telescope

A total of 211 were observed with X-shooter, a multiwavelength (3000–25 000 Å)
echelle spectrograph with medium spectral resolution $R=4000-18\,000$ (Vernet
et al., 2011). Two dichroics are used to split the incoming light into the
three arms for efficient observation of all three arms simultaneously. The UVB
arm (3000–5595 Å), VIS arm (5595–10240 Å) and NIR arm were used (10240–24800
Å). In some cases the NIR range only extended to 21010 Å rather than 24800 Å.
More information on the NIR reductions and scientific results can be found in
Brok et al. (2022).

The majority of observations were observed with 1$\farcs$6, 1$\farcs$5 in the
UVB and VIS arms, respectively, in the NODDING mode and extracted with a 4′′
aperture along the slit. The focus of the program was on obscured AGN (e.g.
Sy1.9 and Sy2) to use the broad wavelength coverage and high spectral
resolution to measure BH masses from velocity dispersion. These observations
were performed as part of a filler program sometimes during bad weather
conditions; however, the median seeing was still 1$\farcs$02 owing to the
inherently good conditions at the VLT. In the case of VLT/X-shooter the
spectra were first reduced using the standard pipeline in the ESO reflex
software (v2.3.0; Freudling et al., 2013).

Another 19 sources were observed as part of the LLAMA sample (Davies et al.,
2015) of low-redshift, luminous BAT AGN ($z{<}0.01$). These sources were
observed in the IFU-offset mode with a field of view (FOV) of $1\farcs
8{\times}4{\mbox{${}^{\prime\prime}$}}$ with resolution $R\sim$8400 and
$R\sim$13200 in the UVB and VIS arms, respectively. The spectra were reduced
using the ESO X-shooter pipeline v2.6.0. The spectra were corrected for
telluric absorption using telluric standard stars. A more detailed description
of the VLT/X-shooter data processing is given in Burtscher et al. (2021).

Finally, three spectra were part of the Science Verification data from
VLT/X-shooter in 2009 and lack header information necessary to be processed in
the standard way using ESO/Reflex. Two of these spectra, obtained in the SLIT,
NODDING mode, were processed using optimal extraction and telluric standard
stars following the reductions procedure of Becker et al. (2019). The UVB arm
was binned to 15 ${\rm\thinspace km}{\rm\thinspace s}^{-1}\,$ pixels. VIS and
NIR arms were binned to 10 ${\rm\thinspace km}{\rm\thinspace s}^{-1}\,$. A
final IFU spectrum of NGC 7319 was extracted with a 4′′ by 2′′ region
following the LLAMA sample.

There were also 69 observations with VLT/FORS2 done in a single observing
semester in 2017 (099.A-0403A) and were focused on Sy1 or Sy1.9 AGN. For
FORS2, the majority were observed with the 600B grating, with 1′′ slit,
covering 3400–6100 Å. A smaller subset of higher-redshift sources ($z{>}0.8$)
was done with the 300I grating covering 6100–11 000 Å. All sources were
reduced with v5.3.32 of the pipeline. Optimal extraction was used with typical
extractions along the slit of 9′′.

####  3.2.3 Southern Astrophysical Research Telescope

We observed 153 sources at the Southern Astrophysical Research (SOAR)
telescope using the Goodman instrument as part of six programs between 2017
and 2020 (P.I. C. Ricci). Observations were acquired in two lower-resolution
setups focused on unobscured AGN with the 400 lines mm-1 grating and GG455
blocking filter or 600 lines mm-1 and GG385 blocking filter. We performed
higher resolution observations of obscured sources focused on the calcium
triplet (CaT: 8498, 8542, and 8662 Å) using the 930 lines mm-1 or 1200 lines
mm-1 grating. Nearly all observations were done with a 1$\farcs$2 slit with
just two sources done with a 0$\farcs$45 slit, because of the very low
velocity dispersions. All sources were extracted optimally, with typically
slit lengths of 4$\farcs$8.

####  3.2.4 du Pont Telescope

Over 11 nights in 2016, 119 AGN were observed with the du Pont telescope with
the Bollens & Chivens spectrograph (P.I. C. Ricci). All sources were observed
with a 1′′slit, the 300 lines mm-1 grating covering 3000–9070 Å. The sources
were extracted with an optimal extraction with typical lengths along the slit
of 6$\farcs$6\. The sources were typically unobscured AGN, due to the
relatively low resolution (FWHM$\sim$8.7 Å).

####  3.2.5 Keck Telescope

Some AGN were also observed with the Keck telescopes associated with
observations of NuSTAR-observed AGN and mergers (e.g., Koss et al., 2016b). A
total of 21 observations were carried out using the Low Resolution Imaging
Spectrometer (LRIS; Oke et al., 1995) on the Keck I Telescope. The setup used
the blue (600 lines -1) grism and the red (400 lines mm-1 grating, with the
D560 dichroic. The majority of observations were done with a 1′′ slit with a
handful done with a 1$\farcs$5 slit.

####  3.2.6 Magellan Telescope

We performed 12 observations with the Magellan Echellete (MagE) spectrograph
(Marshall et al., 2008) on the Magellan Clay telescope. We used a 1′′ slit for
observations with the slit angle set to parallactic. The data were processed
with the MagE pipeline, which is part of the Carnegie Python Distribution
($\mathtt{CarPy}$, v. 1.4.2). The wavelength coverage was $\sim$3300–10000 Å
though there was significant detector fringing above 8280 Å, resulting in
strong instrumental issues above this range. Typical exposure time was 1 hr
and targeted higher-redshift type Sy1.9 and Sy2 AGN ($z{>}0.08$) for velocity
dispersion measurements.

####  3.2.7 SDSS and Archival Data

We also included additional spectra from archival sources. We used spectra
from the SDSS York et al. (2000), with 151 sources from data release 16 (DR16;
Ahumada et al., 2020), which were observed in the legacy survey with 3′′ fiber
at $\sim$3800–9200 Å coverage or 2′′ fiber from BOSS or eBOSS with
$\sim$3600–10200 Å coverage, respectively.

We also include 90 additional archival spectra of AGN that were acquired after
the DR1. These include AGN observed with earlier surveys of ROSAT AGN that
overlap with BASS of unpublished and published (Grupe et al., 2004) sources,
from the Palermo surveys of Swift BAT AGN (Rojas et al., 2017), or as part of
an atlas of low-redshift AGN (Ho & Kim, 2009).

Finally, we include 6 archival spectra from VLT/MUSE when our existing BASS
spectra were insufficient. This includes the nearby Circinus galaxy and NGC
3393, which was too bright to observe using our standard setups and was not
part of the DR1 archival sample. In addition, the dual AGN NGC 6240N and NGC
6240S have a VLT/MUSE spectrum for each AGN obtained in adaptive optics (AO)
mode owing to their close separation. Finally, the relatively distant Sy 2
sources, BAT ID 1204 (z=0.6) and ID 209 (at z=0.09) were included in order to
enable velocity dispersion measurements. We use the processed data from the
ESO Science archive. We extract a 2′′-radius aperture at the WISE position,
except for NGC 6240N and NGC6240S, for which we use an 1′′ aperture owing to
their closeness.

###  3.3 Telluric Absorption Correction

In DR2 we have implemented the software molecfit (Smette et al., 2015) to
correct telluric absorption regions that affect the measurements of emission
and absorption lines. This includes the oxygen bands (the A, B and the weaker
$\Gamma$ bands at $\sim 7590<\lambda/$Å$<7720$, $\sim 6860<\lambda/$Å$<6950$,
and $\sim 6280<\lambda/\AA<6340$, respectively) as well as water vapor bands
($\sim 8100<\lambda/$Å$<8300$, $\sim 8930<\lambda/$Å$<9800$). The performance
has been described already in detail in Kausch et al. (2015) and Smette et al.
(2015) for ESO instruments.

In molecfit, model spectra are fitted to the observed spectra to derive the
best-fit atmospheric parameters by iteratively computing transmission curves
using a simple Earth atmosphere structure at the time of observation. Global
weather data are combined with local weather data to provide a likely best fit
(humidity, pressure, temperature). We use four regions with strong atmospheric
features (O2 at $\sim 6800<\lambda/$Å$<6900$, O2 at $\sim
7460<\lambda/$Å$<7560$, telluric regions at $\sim 9100<\lambda/$Å$<9200$, and
telluric regions at $\sim 9400<\lambda/$Å$<9500$) to determine the best-fit
atmospheric parameters. An example is provided in Figure Figure 5. We mask
regions with strong AGN emission-line features from the fitting. We use a
Gaussian kernel variable with wavelength (varkern=1).

Telluric corrections with molecfit were applied to all spectra with coverage
above 7500 Å except archival observations (which lacked local weather data),
Magellan/MAGE observations (because of significant fringing), and SDSS spectra
(which have already had this correction applied). An example of the telluric
correction and its importance for narrow- and broad-line measurements is
provided in Figure Figure 6. We note that the ability to recover the intrinsic
spectra is dependent the ability to measure foreground atmospheric absorption
lines in the source, and thus very faint intrinsic spectra, such as those with
very high Galactic extinction have little or no correction. While most
spectroscopic regions were adequately corrected, the 9300-9700Å region suffers
very high extinction, and emission-line fitting should be approached with
caution.

Figure 5: Example absorption-line fit of the model spectrum to the observed
spectrum using synthetic kernels of Gaussian kernels in the O2 A-band region
($\sim$7580-7680 Å).

Figure 6: Figure showing molecfit correction on a spectrum within the BASS
DR2. Top left: VLT/X-shooter spectra of a broad-line BAT AGN Fairall 9 in the
visual arm (5500-10500 Å). Top right panel and middle row show zoom-in regions
around absorption features. The red lines are the telluric-absorption-
corrected (TAC) spectra, and gray lines are the input raw spectra. The
telluric absorption features cover broad H$\alpha$as well as the prominent
narrow emission lines at He ii$\,\lambda 8237$ and [S ii] $\lambda 9531$
emission lines. molecfit recovers these emission lines as shown with the TAC
spectra, which are particularly important for accurately measuring H$\alpha$,
He ii$\,\lambda 8237$, and [S ii] $\lambda 9531$. The bottom row shows the CaT
region before (left) and after (right) molecfit correction when being fit with
a galaxy template for a velocity dispersion measurement (Koss et al., 2022b).
The model fit is shown in red, with residuals from the fit shown in green dots
below the spectra. The TAC spectrum is able to recover a larger region of the
Ca ii triplet spectral region (8450–8700 Å) which is redshifted into telluric
features at $z{>}0.04$ with no significant increase in residuals.

####  3.3.1 Overlap with the DR1

Initial targeting priority focused on sources without BH mass measurements or
spectra from the archival data in the DR1, but this was later expanded to
complete the whole sample. The DR2 includes all of the SDSS spectra in the DR1
as well as 35 early Palomar spectra that were reprocessed to include
corrections with molecfit. Beyond this there are still 42 AGN in the DR1, with
no new DR2 spectra.

###  3.4 Instrumental Resolution

We determine the instrumental resolution and line-spread function (LSF) FWHM
for each spectral setup and provide the best estimate in Table 7. A
description of how this quantity was measured is given in subsection 3.4.

For some sources we perform Gaussian fits of night-sky lines including Hg I
(e.g. 4046 Å, 4358 Å, and 5461 Å) and OI (5577 Å, 6300 Å, and 6364 Å) for
bluer spectral regions. We used OH lines for redder regions (e.g. 6864 Å, 7341
Å, 7821 Å, and 9872 Å). If this was not feasible owing to spectral coverage,
we used arc line spectra.

In real observations, the slit width is not the only factor in determining the
instrumental resolution. If the slit is large, the image quality at the
entrance slit can be smaller than the slit width. The observed spectral
resolution is then better than what is measured from the slit width for arc or
sky lines which fully fill the slit, but is instead determined by the
sharpness of the image of the object at the entrance slit. Thus, the spectral
resolution in real observations of AGN may be somewhat smaller than when
measured using sky lines or arc line spectra that fully fill the slit.

The measurements from molecfit, which trace the absorption of telluric lines,
can provide an additional estimate of the effective resolution. We note,
however, that the ability to fit the absorption profile is difficult in faint
sources and only done for setups that include coverage of telluric features
(e.g., ${>}$9000 Å). In several setups without telluric features, only a few
AGN were observed, and we use sky or arc lines for resolution measurements.

An independent estimate of the spectral resolution and the line spread was
also done with the penalized PiXel-Fitting method (pPXF, Cappellari &
Emsellem, 2004; Cappellari, 2017) by fitting stellar absorption lines to
individual Galactic stars that were observed during the observations. We use
two template libraries depending on the resolution. We use the X-shooter data
release 2 library, which was obtained at much higher resolutions than typical
observations (e.g. $R\sim 10000$). For spectra obtained at higher resolutions
($R>$3000) based on sky lines, we use the $\mathtt{PHOENIX}$ theoretical
spectral library (Husser et al., 2013) as a template which has much higher
resolutions ($R\sim 500,000$). We fit the 3880–5500 Å region and 8350–8730 Å
to determine the LSF in the blue and red ranges, respectively, to target
stellar absorption features.

We find that the spectral resolution as measured from individual Galactic
stars during real observations or telluric absorption lines in the AGN
galaxies tends to indicate spectral resolutions somewhat sharper ($\sim 20\%$)
than those of sky lines. For instance, for the largest sample observed using
the 1.5′′ slit with Palomar/Doublespec, the average of stars observed on
different nights is $4.7\pm 0.3$ Å in the CaT, compared to the average of the
telluric absorption with molecfit which is $4.9\pm 0.6$ Å. The average from
fitting sky lines for these observations is 5.8$\pm$0.3 Å. In this case, we
use use the molecfit average, though it is statistically similar to that from
stars. For the 3880–5500 Å region, molecfit was not used because of a lack of
telluric features, but the pPXF fits were $4.1\pm 0.2$ Å vs. $4.8\pm 0.4$ Å
for the sky lines within each observation, and the average of the pPXF fits
was used.

##  4 Survey Measurements

The spectroscopic release provides spectra for 95.1% (816/858) of DR2 AGN.
When combined with the DR1 spectra, all AGN have spectra (e.g. 100%, 858/858),
representing a complete census of luminous hard-X-ray-selected AGN over nearly
the entire sky outside of a small region on the Galactic plane (94.8%,$\lvert
b\rvert{>}3^{\circ}$). Here we describe the main survey measurements (e.g.
$z$, AGN type, $M_{\rm BH}$). Further derived measurements (broad-line widths,
narrow-line widths, velocity dispersions) will be provided in subsequent
papers.

For all the AGN in our sample, we provide the following key parameters when
possible for each AGN Table 9:

  1. 1.

BAT ID: Catalog ID in the BAT
survey.444https://swift.gsfc.nasa.gov/results/bs70mon/

  2. 2.

R.A. $\alpha_{\rm J2000}$ and decl. $\delta_{\rm J2000}$: Right ascension and
decl. of the optical/IR counterpart of the BAT AGN, in decimal degrees, based
on WISE positions.

  3. 3.

DR2 Type: AGN type based on optical spectroscopy. Sy1 (with broad H$\beta$),
Sy1.9 (narrow H$\beta$ and broad H$\alpha$), and Sy 2 (with narrow H$\beta$
and H$\alpha$). For beamed AGN, the types include those with the presence of
broad lines (BZQ), only host galaxy features lacking broad lines (BZG), or
traditional continuum-dominated blazars with no emission lines or host galaxy
features (BZB). BZU refers to a beamed AGN where the type is uncertain because
of a lack of optical spectroscopy or very low S/N.

  4. 4.

$z$ and $z_{\textrm{type}}$: Best DR2 redshift measurement and the line or
method used for the measurement. The majority of fits are done with [O iii]
$\lambda 5007$ (88%, 755/858). Measurements are from a broad-line fitting code
(Mejía-Restrepo et al., 2022) referred to as OIII broad, MgII broad, and CIV
broad, respectively, when available for all Sy1 and BZQ sources with broad-
line H$\beta$. For narrow-line sources, the redshift is based on emission-line
fitting of [O iii] $\lambda 5007$, when possible. For some high Galactic
extinction sources, single emission-line fits to other lines are used (in the
table as Ha for H$\alpha$, SIII for [S ii] $\lambda 9531$, and HeI for He
ii$\,\lambda 10830$). For some high-redshift sources $z{>}1$ without high
quality broad-line fitting we report the estimates from single emission-line
fits of C iv $\lambda 1549$ and Mg ii $\lambda 2798$ (referred to as CIV and
MgII). Host galaxy templates (referred to as Gal Temp) are used for some BZB
with no emission lines. For the remaining sources, DR1 fits or those from
SIMBAD are used for redshift estimates.

  5. 5.

Dist and z${}_{\textrm{ind}}$: Distance assumed based on redshift or redshift
independent distance measurements in Mpc.

  6. 6.

Best MBH and MBH${}_{\textrm{Meth}}$. The best BH mass measurement and the
method used for the measurement. We do not report errors from either broad-
line fitting or velocity dispersions as the they are less than 0.1 dex and the
errors are dominated by the intrinsic spread of virial and $\sigma_{\star}$
based BH mass estimates of order 0.5 dex (Ricci et al., 2022).

  7. 7.

$L_{\rm bol}$ and $L/L_{\rm Edd}$: Measurement of the AGN bolometric
luminosity and Eddington ratio based on BH mass.

Table 9: General AGN Properties

BAT ID | Counterpart | R.A. | Decl. | DR2 Type | $z$ | $z_{\mathrm{type}}$ | Dist | $M_{\mathrm{BH}}$ | BH meth. |  $\log$ $L_{\rm bol}$ | $L/L_{\rm Edd}$
---|---|---|---|---|---|---|---|---|---|---|---
|  | (∘) | (∘) |  |  |  | (Mpc) | ($M_{\odot}$) |  | ($\log$(${\rm\thinspace erg}{\rm\thinspace s}^{-1}\,$)) |
1 | 2MASXJ00004876-0709117 | 0.203234 | -7.153223 | Sy1.9 | 0.037496 | OIII | 165.2 | 7.61 | Vdisp | 44.45 | -1.33
2 | 2MASXJ00014596-7657144 | 0.442035 | -76.953963 | Sy1 | 0.058505 | OIII Broad | 261.7 | 7.41 | Hb | 44.77 | -0.82
3 | NGC7811 | 0.610105 | 3.351912 | Sy1 | 0.025457 | OIII Broad | 111.2 | 6.70 | Hb | 44.01 | -0.86
4 | 2MASXJ00032742+2739173 | 0.864248 | 27.654725 | Sy2 | 0.039784 | OIII | 175.6 | 7.89 | Vdisp | 44.52 | -1.55
5 | 2MASXJ00040192+7019185 | 1.008241 | 70.321752 | Sy2 | 0.095681 | OIII | 439.1 | 6.20 | Ha obs | 45.29 | 0.92
6 | Mrk335 | 1.581400 | 20.202951 | Sy1 | 0.025906 | OIII Broad | 113.2 | 7.23 | Lit | 44.24 | -1.17
7 | SDSSJ000911.57-003654.7 | 2.298335 | -0.615222 | Sy2 | 0.073345 | OIII | 331.5 | 8.54 | Vdisp | 45.05 | -1.67
8 | Mrk1501 | 2.629175 | 10.974862 | BZQ | 0.089385 | OIII Broad | 408.5 | 8.07 | Lit | 45.63 | -0.61
9 | [HB89]0014+813 | 4.285420 | 81.585596 | BZQ | 3.377817 | CIV Broad | 29310.9 | 9.90 | CIV | 48.90 | 0.82
10 | LEDA1348 | 5.281408 | -19.168191 | Sy1.9 | 0.095846 | OIII | 439.9 | 8.94 | Vdisp | 45.41 | -1.70
13 | LEDA136991 | 6.385030 | 68.362439 | Sy2 | 0.012492 | OIII | 54.0 | 7.68 | Vdisp | 43.94 | -1.92
14 | LEDA433346 | 6.669470 | -53.163275 | Sy1 | 0.063219 | OIII Broad | 283.7 | 8.44 | Hb | 44.99 | -1.63
16 | PG0026+129 | 7.307096 | 13.267761 | Sy1 | 0.141997 | OIII Broad | 671.7 | 8.49 | Lit | 45.68 | -0.98
17 | ESO112-6 | 7.682626 | -59.007215 | Sy2 | 0.029004 | OIII | 127.0 | 7.90 | Vdisp | 44.44 | -1.64
18 | 2MASXJ00331831+6127433 | 8.326442 | 61.462015 | Sy1.9 | 0.104184 | OIII | 480.9 | 7.95 | Ha | 45.42 | -0.71
19 | RHS3 | 8.570040 | -79.088963 | Sy1 | 0.074268 | OIII Broad | 335.9 | 8.02 | Hb | 44.79 | -1.41
20 | 2MASXJ00343284-0424117 | 8.636619 | -4.403423 | Sy2 | 0.212982 | OIII | 1051.6 | 9.22 | Vdisp | 46.22 | -1.18
22 | Z535-12 | 9.087263 | 45.664900 | Sy1 | 0.047608 | OIII Broad | 211.3 | 7.36 | Hb | 44.75 | -0.79
24 | Mrk344 | 9.633812 | 23.613408 | Sy2 | 0.025246 | OIII | 110.2 | 7.54 | Vdisp | 44.29 | -1.43
25 | SWIFT J004039.9+244539 | 10.166178 | 24.760937 | Sy1.9 | 0.078365 | OIII | 355.4 | 7.73 | Vdisp | 44.86 | -1.05
28 | NGC235A | 10.720042 | -23.541046 | Sy1.9 | 0.022065 | DR1 | 96.1 | 8.49 | Vdisp | 44.61 | -2.06
30 | 2MASXJ00423991+3017515 | 10.666287 | 30.297621 | BZQ | 0.140128 | OIII Broad | 662.1 | 8.56 | Hb | 45.41 | -1.33

Note. — Table 9 is published in its entirety in the machine-readable format
for 858 AGN. A portion is shown here for guidance regarding its form and
content. See subsection 3.1 for a description of each data column.

###  4.1 AGN Type

For classification, we first split the sources into 752 unbeamed AGN and 105
beamed AGN (and 1 lensed AGN) following the spectroscopic classification of
the Roma Blazar Catalog catalog (BZCAT; Massaro et al., 2009). The beamed AGN
were split into three categories based on their optical spectral properties,
specifically, based on the presence of broad lines (BZQ), only host galaxy
features lacking broad lines (BZG), or traditional continuum-dominated blazars
with no emission lines or host galaxy features (BZB).

Overall 72/105 (69%) of the DR1 beamed AGN maintained the same classification
with further optical spectroscopic study. 20/105 (19%) changed specific beamed
AGN classification based on additional DR2 optical spectra (e.g., BZG to BZQ,
based on the detection of broad H$\beta$ or any other broad line such as
H$\alpha$).

We provide an unbeamed AGN type based on the presence of broad Balmer lines
from visual inspection after fitting with host galaxy templates (Koss et al.,
2022b). These include sources with broad H$\beta$ (Sy1), sources with narrow
H$\beta$, but broad H$\alpha$ (Sy1.9), and sources with only narrow optical
lines (Sy2). Further classification of broad-line AGN (e.g. Sy 1.2, 1.5, 1.8
etc.) is provided in subsequent studies (Mejía-Restrepo et al., 2022) and also
of narrow-line AGN such as LINERs (Oh et al., 2022). When spectra are not
available in DR2 for AGN type, we use the DR1 AGN type.

Overall, there are 168 AGN in DR2 for which we derive a revised or first
classification of AGN type based on our measurements. A detailed comparison of
DR2 measurements compared to the DR1 is provided in Appendix A.

###  4.2 Redshifts

To determine the best redshifts for the sample Table 10, we use the [O iii]
$\lambda 5007$ line emission as the primary measurement. For broad line
sources (e.g. Sy1 and BZQ), the [O iii] redshift is based on the fitting
procedure in Mejía-Restrepo et al. (2022) which is consistent with the
procedure used in the DR1. For more distant beamed AGN, when the [O iii]
$\lambda 5007$ line is redshifted out of the spectrum, the Mg ii $\lambda
2798$ ($0.8{<}z{<}2.6$) or C iv $\lambda 1549$ ($2.1{<}z{<}3.6$) line is used.

For the Sy1.9 and Sy2 AGN, or any broad-line AGN where the fitting failed, we
fit the [O iii] emission line in our sample using PySpecKit, an extensive
spectroscopic analysis toolkit for astronomy, which uses a Levenberg-Marquardt
algorithm for spectral fitting (Ginsburg & Mirocha, 2011). We fit the [O iii]
emission line using a single Gaussian. Finally, for 10 sources that are highly
reddened and often in the Galactic plane where an [O iii] line was not
detected we use the H$\alpha$ or [S ii]$\,\lambda 6717,6731$ or He
ii$\,\lambda 10830$ line. We note that for NGC6240N and NGC6240S, the sources
were too close together to resolve in our spectra, so we provide a single
measurement.

There are 30 beamed AGN that are strongly continuum-dominated blazars (BZB),
with only weak stellar features, and host-galaxy-dominated blazars (BZG),
where no [O iii] $\lambda 5007$ emission lines are measured. For 25 of these
sources, we can measure redshifts using pPXF with the Ca H+K lines or Ca ii
absorption features. Further details, including a full list of redshifts from
stellar absorption features from galaxy template fits for Sy1.9 and Sy2 AGN
can be found in Koss et al. (2022b).

We used the BASS DR1 data for the 33 AGN in DR2, which did not have a new
spectrum at all or were missing one that covered the [O iii] $\lambda 5007$
line.

For the remaining sources we rely on NED or SIMBAD or past publications for
redshift measurements. Of the remaining six BZB sources we could not detect
strong host galaxy features for a redshift, there are five sources with an
existing redshift from NED or SIMBAD, which we use as the redshift
measurement. There is one very high-extinction AGN ($A_{V}$=9.5) 2MASS
J10445192-6025115, which was found to have a redshift of $z{=}0.047$ (Fortin
et al., 2018) based on He ii$\,\lambda 10830$ line. The beamed and lensed AGN
PKS 1830-21, was measured using H$\alpha$ in the NIR at $z{=}2.507$ (Lidman et
al., 1999) due to it’s high extinction ($A_{V}$) from being in the Galactic
plane.

Overall the redshift completion is extremely high, 99.8% (857/858) for the
full sample. Of these AGN redshifts, 47 (Table 11) are found for the first
time (Figure 7). The only AGN without a redshift is a continuum-dominated
blazar (BZB). The blazar, B3 0133+388, was first discovered in the third
Bologna sky survey of 408 MHz radio objects (Ficarra et al., 1985) and is also
shows bright gamma-ray emission above 1 GeV in Fermi. The source shows faint
Ca H+K lines at redshift zero in two different Palomar spectra (and also in a
Keck/LRIS spectra shown in Aliu et al. (2012)). However, given the radio and
Fermi detection, the source is unlikely to be Galactic but maybe a blazar with
a foreground star.

Figure 7: Examples of 47 sources with newly identified redshifts. Table 10:
Summary of Redshift Measurements

Redshift Method | Count
---|---
[O iii] $\lambda 5007$ | 393
[O iii] $\lambda 5007$ Broad | 364
DR1 | 34
Gal Temp | 22
C iv $\lambda 1549$ Broad | 13
Mg ii $\lambda 2798$ Broad | 10
H$\alpha$ | 7
SIMBAD | 6
C iv $\lambda 1549$ | 3
[S ii] $\lambda 9531$ | 3
He ii$\,\lambda 10830$ | 1
NED | 1
None | 1

Note. — The [O iii] broad redshift indicates that a broad line fitting
procedure for H$\beta$ was used as described in (Mejía-Restrepo et al., 2022).
Otherwise a single emission-line fit or a galaxy template fit was performed.
See subsection 4.2 for details.

Table 11: Newly Identified Redshifts

BAT Index | Swift Name | Counterpart | DR2 Type | Telescope | $z$ | Line | $A_{V}$
---|---|---|---|---|---|---|---
25 | SWIFT J0041.0+2444 | SWIFT J004039.9+244539 | Sy1.9 | Palomar/DBSP | 0.078365 | [O iii] $\lambda 5007$ | 0.1
42 | SWIFT J0057.0+6405 | NVSS J005712+635942 | BZQ | Palomar/DBSP | 0.289627 | [O iii] | 4.5
65 | SWIFT J0116.5-1235 | 2MASX J01163118-1236171 | Sy1.9 | VLT/X-shooter | 0.142447 | [O iii] | 0.1
92 | SWIFT J0149.2+2153A | LEDA 1656658 | Sy1.9 | Palomar/DBSP | 0.069397 | [O iii] | 0.3
154 | SWIFT J0252.1-6758 | 2MASX J02513173-6803059 | Sy1.9 | VLT/X-shooter | 0.18263 | [O iii] | 0.1
161 | SWIFT J0259.9+4419 | 2MASX J02593756+4417180 | Sy1 | Palomar/DBSP | 0.031291 | [O iii] | 0.7
210 | SWIFT J0413.3+1659 | MG1J041325+1659 | BZQ | Palomar/DBSP | 0.211541 | [O iii] | 2.1
240 | SWIFT J0449.6-5515 | 2MASX J04500193-5512404 | Sy2 | VLT/X-shooter | 0.021576 | [O iii] | 0
250 | SWIFT J0459.7+3502 | LEDA168924 | Sy2 | Palomar/DBSP | 0.044383 | [O iii] | 2.8
257 | SWIFT J0505.6-6735 | 2MASX J05052442-6734358 | Sy2 | VLT/X-shooter | 0.046517 | [O iii] | 0.8
323 | SWIFT J0612.2-4645 | PMN J0612-4647 | BZQ | VLT/X-shooter | 0.317767 | [O iii] | 0.2
333 | SWIFT J0626.6+0729 | LEDA136513 | Sy1 | duPont/BC | 0.042447 | [O iii] | 2
343 | SWIFT J0640.0-4737 | SWIFT J064013.50-474132.9 | Sy2 | VLT/X-shooter | 0.057242 | [O iii] | 0.4
353 | SWIFT J0659.3+2406 | 2MASX J06591070+2401400 | Sy2 | Keck/LRIS | 0.090822 | [O iii] | 0.2
359 | SWIFT J0709.3-1527 | PKS 0706-15 | BZB | Palomar/DBSP | 0.142277 | Gal. Temp. | 2
367 | SWIFT J0723.8-0804 | 1RXS J072352.4-080623 | Sy1 | Palomar/DBSP | 0.144926 | [O iii] | 0.9
380 | SWIFT J0741.4-5447 | 2MASX J07410919-5447461 | Sy2 | VLT/X-shooter | 0.106098 | [O iii] | 0.5
396 | SWIFT J0755.4+8402 | 2MASS J07581638+8356362 | Sy1 | Palomar/DBSP | 0.133952 | [O iii] | 0.15
433 | SWIFT J0854.3-0827 | SWIFT J085429.35-082428.6 | Sy2 | VLT/X-shooter | 0.188435 | [O iii] | 0.1
487 | SWIFT J1007.4+6534 | 1RXSJ100712.6+653511 | Sy1 | Palomar/DBSP | 0.126589 | [O iii] | 0.2
494 | SWIFT J1020.5-0237A | SDSS J102103.08-023642.6 | Sy2 | VLT/X-shooter | 0.293645 | [O iii] | 0.13
510 | SWIFT J1041.4-1740 | 2MASX J10410120-1734300 | Sy2 | VLT/X-shooter | 0.080844 | [O iii] | 0.2
660 | SWIFT J1310.9-5553 | IGR J13109-5552 | BZQ | VLT/X-shooter | 1.55906 | Mg ii $\lambda 2798$ | 1.1
745 | SWIFT J1449.5+8602 | 2MASX J14545815+8554589 | Sy2 | Palomar/DBSP | 0.111951 | [O iii] | 0.5
747 | SWIFT J1451.0-5540B | LEDA 3085605 | Sy2 | VLT/X-shooter | 0.018663 | H$\alpha$ | 2.5
756 | SWIFT J1508.6-4953 | PMNJ1508-4953 | BZQ | VLT/X-shooter | 1.520201 | Mg ii $\lambda 2798$ | 1.2
761 | SWIFT J1512.2-1053A | NVSS J151148-105023 | BZQ | Palomar/DBSP | 0.94672 | [O iii] | 0.34
762 | SWIFT J1512.2-1053B | 2MASX J15120505-1046356 | Sy2 | VLT/X-shooter | 0.165799 | [O iii] | 0.3
780 | SWIFT J1548.1-6406 | SWIFT J1548.1-6406 | BZQ | VLT/X-shooter | 1.693124 | [O iii] | 0.6
792 | SWIFT J1605.9-7250 | LEDA 259433 | Sy2 | VLT/X-shooter | 0.069271 | [O iii] | 0.3
894 | SWIFT J1733.3+3635 | 2MASX J17333689+3631319 | Sy1.9 | Palomar/DBSP | 0.043661 | [O iii] | 0.1
897 | SWIFT J1737.7-5956A | 1RXS J173751.2-600408 | BZQ | VLT/X-shooter | 3.656025 | [O iii] | 0.2
906 | SWIFT J1742.1-6054 | PKS 1737-60 | Sy1 | SOAR/GM | 0.152012 | [O iii] | 0.2
974 | SWIFT J1825.7+7215 | LEDA 61865 | Sy2 | Palomar/DBSP | 0.110806 | [O iii] | 0.2
1000 | SWIFT J1852.2+8424A | SWIFT J185024.2+842240 | Sy1 | Palomar/DBSP | 0.183122 | [O iii] | 0.3
1001 | SWIFT J1852.2+8424B | 1RXS J184642.2+842506 | Sy1 | Palomar/DBSP | 0.225381 | [O iii] | 0.3
1007 | SWIFT J1852.8+3002 | GALEXASC J185249.68+300425.8 | Sy1.9 | Palomar/DBSP | 0.057301 | [O iii] | 0.6
1066 | SWIFT J2010.6-2521 | 1RXS J201020.0-252356 | BZQ | VLT/X-shooter | 0.824924 | [O iii] | 0.5
1075 | SWIFT J2024.0-0246 | 1RXS J202400.8-024527 | Sy1.9 | VLT/X-shooter | 0.137523 | [O iii] | 0.2
1078 | SWIFT J2029.4-6149 | 2MASX J20293125-6149087 | Sy2 | VLT/X-shooter | 0.124274 | [O iii] | 0.2
1083 | SWIFT J2034.0-0943 | 2MASX J20341926-0945586 | Sy2 | VLT/X-shooter | 0.081551 | [O iii] | 0.2
1091 | SWIFT J2048.4+3815 | 1RXS J204826.8+381120 | Sy1 | Palomar/DBSP | 0.105394 | [O iii] | 2.8
1096 | SWIFT J2059.6+4301B | SWIFT J210001.06+430209.6 | Sy2 | Palomar/DBSP | 0.066023 | [O iii] | 4.1
1105 | SWIFT J2117.5+5139 | 2MASX J21174741+5138523 | BZQ | Palomar/DBSP | 0.053392 | [S ii] $\lambda 9531$ | 9.7
1130 | SWIFT J2156.2+1724 | 2MASX J21561518+1722525 | Sy1.8 | VLT/X-shooter | 0.03417 | [O iii] | 0.3
1164 | SWIFT J2243.2-4539 | 2MASX J22422135-4539093 | Sy1.9 | VLT/X-shooter | 0.120675 | [O iii] | 0
1208 | SWIFT J2352.6-1707 | 2MASX J23525143-1704370 | Sy1 | duPont/BC | 0.054695 | [O iii] | 0.1

Note. — Column descriptions are the same as in Table 1, unless otherwise
noted. A detailed description of this table’s contents is given in section 4.

###  4.3 Distance and Luminosity

The AGN host galaxies span a large range of redshifts down to very nearby
(${<}50$ Mpc) systems. These AGN can have substantial peculiar velocities
compared to velocities of the Hubble flow where a simple assumption of uniform
expansion would lead to large errors. High-quality redshift-independent
distances to nearby galaxies such as through using the tip of the red giant
branch (TRGB) are now available (e.g., McQuinn et al., 2017). Further
compilations such as the Extragalactic Distance Database (EDD, Tully et al.,
2009) or the Cosmicflows-3 project (Courtois et al., 2017) have now compiled
motions of many thousands of local galaxies.

We follow the approach of Leroy et al. (2019), which performed a careful
analysis of which compilations to adopt at different distances based on
statistical uncertainties. Specifically, we limit our search to ${<}$50 Mpc
(or 3500 ${\rm\thinspace km}{\rm\thinspace s}^{-1}\,$) galaxies to adopt
redshift-independent distances as beyond this the typical uncertainties are
larger than those in the Hubble flow. We focus on using EDD, Cosmicflows, and
NED for adopting distances. We adopt a TRGB and ”quality” distances from EDD
whenever available. When this is not available, we take the Cosmicflows-3
value. If none of these are available, we use the most recent redshift-
independent estimate from NED. This results in redshift-independent
measurements for all 59 galaxies (Table 12) below 3500 ${\rm\thinspace
km}{\rm\thinspace s}^{-1}\,$in our survey.

Table 12: Redshift Independent Distances  BAT ID | Counterpart | $z$ | Dist. Ind. [Mpc] aaBest redshift-independent distance. See subsection 4.2 for a detailed description of the redshift-independent measurements. | Dist. $z$ [Mpc] | MethodbbTRGB: tip of the red giant branch (e.g., McQuinn et al., 2017), CF3: Cosmicflows-3 project (Courtois et al., 2017), NED: NASA Extragalactic Database.
---|---|---|---|---|---
655 | NGC4945 | 0.002259 | 3.72 | 9.7 | TRGB
671 | CenA | 0.001877 | 3.66 | 8.1 | TRGB
477 | M81 | -0.000113 | 3.61 | 0 | TRGB
711 | CircinusGalaxy | 0.001495 | 4.21 | 6.4 | NED
616 | NGC4395 | 0.001106 | 4.76 | 4.7 | TRGB
609 | NGC4258 | 0.001692 | 7.31 | 7.3 | TRGB
585 | NGC4051 | 0.002043 | 11.02 | 8.8 | CF3
838 | NGC6221 | 0.004108 | 11.86 | 17.6 | CF3
731 | NGC5643 | 0.004042 | 12.68 | 17.4 | TRGB
875 | NGC6300 | 0.003131 | 13.18 | 13.4 | CF3
593 | NGC4138 | 0.003187 | 13.7 | 13.7 | SBF
144 | NGC1068 | 0.003484 | 14.4 | 15 | NED
579 | NGC3998 | 0.003574 | 14.19 | 15.3 | SBF
686 | NGC5273 | 0.003606 | 16.6 | 15.5 | SBF
1157 | NGC7314 | 0.004607 | 16.75 | 19.8 | CF3
548 | NGC3718 | 0.003278 | 17.1 | 14.1 | NED
216 | NGC1566 | 0.00474 | 17.9 | 20.4 | TRGB
615 | NGC4388 | 0.008344 | 18.11 | 36 | CF3
595 | NGC4151 | 0.003152 | 19 | 13.5 | NED
665 | NGC5033 | 0.002763 | 19.05 | 11.9 | CF3
140 | NGC1052 | 0.004519 | 19.23 | 19.4 | SBF
590 | NGC4102 | 0.002365 | 19.5 | 10.1 | CF3
184 | NGC1365 | 0.005091 | 19.57 | 21.9 | TRGB
653 | NGC4941 | 0.003881 | 20.45 | 16.7 | NED
484 | NGC3079 | 0.003505 | 20.61 | 15 | CF3
1142 | NGC7213 | 0.004767 | 22 | 20.5 | NED
1188 | NGC7582 | 0.005249 | 22.49 | 22.6 | CF3
1046 | NGC6814 | 0.005792 | 22.8 | 24.9 | NED
497 | NGC3227 | 0.003277 | 22.95 | 14.1 | NED
436 | NGC2655 | 0.004854 | 24.4 | 20.9 | NED
712 | NGC5506 | 0.005979 | 26.4 | 25.7 | NED
607 | NGC4235 | 0.007934 | 26.6 | 34.2 | SBF
1180 | NGC7465 | 0.006343 | 27.2 | 27.3 | NED
319 | ESO5-4 | 0.006162 | 28.18 | 26.5 | CF3
437 | NGC2712 | 0.006754 | 31.19 | 29.1 | CF3
480 | NGC3081 | 0.008071 | 32.5 | 34.8 | NED
1135 | NGC7172 | 0.008511 | 33.9 | 36.7 | NED
823 | ESO137-34 | 0.008759 | 34.1 | 37.8 | NED
308 | NGC2110 | 0.0075 | 34.3 | 32.3 | NED
93 | NGC678 | 0.009485 | 34.5 | 40.9 | NED
688 | NGC5290 | 0.008566 | 34.51 | 36.9 | CF3
621 | NGC4500 | 0.010357 | 34.51 | 44.7 | CF3
1184 | NGC7479 | 0.007105 | 36.81 | 30.6 | CF3
631 | NGC4593 | 0.00832 | 37.2 | 35.9 | NED
739 | NGC5728 | 0.010321 | 37.5 | 44.6 | CF3
471 | NGC2992 | 0.007675 | 38 | 33.1 | NED
558 | NGC3783 | 0.008958 | 38.5 | 38.6 | NED
103 | LEDA89913 | 0.011836 | 38.8 | 51.2 | NED
530 | NGC3516 | 0.008718 | 38.9 | 37.6 | NED
654 | NGC4939 | 0.010543 | 42.07 | 45.5 | CF3
599 | NGC4180 | 0.006532 | 43.05 | 28.1 | CF3
560 | NGC3786 | 0.008916 | 43.9 | 38.4 | NED
766 | NGC5899 | 0.008597 | 45.08 | 37.1 | CF3
1092 | IC5063 | 0.011267 | 45.9 | 48.7 | NED
237 | LEDA86269 | 0.010529 | 46.13 | 45.5 | CF3
62 | IC1657 | 0.011688 | 48.31 | 50.5 | CF3
58 | NGC424 | 0.010885 | 51.05 | 47 | CF3
684 | NGC5283 | 0.010365 | 51.52 | 44.7 | CF3
451 | IC2461 | 0.007535 | 58.88 | 32.5 | CF3

###  4.4 Black Hole Mass, Bolometric Luminosity, and Eddington Ratios

We also provide the best BH mass measurements for each AGN in our catalog
outside of continuum-dominated blazars (BZB). A small number of sources have
direct (or higher-quality) measurements of BH masses, either from
reverberation mapping ($N$=48), OH megamasers ($N$=10), or high-quality IFU
observations of gas or stars ($N$=12) which we have adopted and tabulated when
available.

Some AGN may have multiple BH mass measurements from broad lines and velocity
dispersions, so we select the best measurement (Table 13) based on the
following ordered scheme:

  1. 1.

Literature measurements with megamasers, reverberation mapping, or stellar and
gas dynamics.

  2. 2.

Broad-line H$\beta$ if $N_{\rm H}$${<}10^{22}$ cm-2 from Mejía-Restrepo et al.
(2022). The conversion of broad-line measurements to BH masses is given by
Trakhtenbrot & Netzer (2012).

  3. 3.

Broad-line H$\alpha$ from Mejía-Restrepo et al. (2022) if $N_{\rm
H}$${<}10^{22}$ cm-2 and broad-line H$\beta$ is present but not measurable
because of instrumental or telluric issues. They use Greene & Ho (2005), but
adjusted by 4/3 (or +0.125 dex) for a consistent virial factor of 1 across all
broad-line measurements.

  4. 4.

Broad-line Mg ii $\lambda 2798$ followed by C iv $\lambda 1549$ for high-
redshift sources ($z{>}0.8$) from Mejía-Restrepo et al. (2022) for those
without broad-line H$\beta$ using the relation of Mejia-Restrepo et al.
(2016).

  5. 5.

Stellar velocity dispersion measurements for all Sy1.9 and Sy2 AGN from Koss
et al. (2022b). We calculated the BH mass, $M_{\rm BH}$, using the $M_{\rm
BH}-\sigma_{*}$ relation of equation 13 from Kormendy & Ho (2013).

  6. 6.

If $N_{\rm H}$${>}10^{22}$ cm-2, and if no velocity dispersion measurement is
possible, broad-line H$\alpha$ followed by broad-line H$\beta$ is used from
Mejía-Restrepo et al. (2022). These final measurements should be used with
caution because of the tendency to underestimate $M_{\rm BH}$ due to
obscuration (e.g., Mejía-Restrepo et al., 2022; Ricci et al., 2022; Brok et
al., 2022)

A summary of the number of best BH mass measurements is found in Figure 8. The
majority of measurements come from either velocity dispersion measurements or
broad H$\beta$ with a smaller number from literature measurements, broad
H$\alpha$, broad H$\alpha$ in X-ray-obscured AGN ($N_{\rm H}$${>}10^{22}$
cm-2), and Mg ii $\lambda 2798$ or C iv $\lambda 1549$ broad lines for distant
beamed AGN ($z{>}1$). See Mejía-Restrepo et al. (2022) and Koss et al. (2022b)
for more details about the individual observations, calculations, and
methodologies.

The bolometric luminosity is calculated from the intrinsic luminosity in the
14–150 keV range as shown in (see Table 12, Ricci et al., 2017b). This
analysis was done using the 0.3–150 keV range by combining the 70-month
average Swift BAT spectra with data below 10 keV from Swift XRT, XMM-Newton,
Chandra, Suzaku, and ASCA using detailed spectral models. Here we calculated
the bolometric luminosity using a 14–150 keV bolometric correction of 8 based
on the factor of 20 for the 2–10 keV range (Vasudevan & Fabian, 2009) and
assuming $\Gamma$=1.8. We prefer this rather than using the direct calculation
from the 2–10 keV range because the corrections are less dependent on $N_{\rm
H}$ for CT AGN. The 14–150 keV emission is also integrated over 70 months, so
it is more likely to be representative of the average value.

For Eddington ratios we assume an Eddington luminosity consistent with solar
metallicity:

$L_{\rm Edd}=1.5\cdot 10^{46}\,\text{erg
s}^{-1}\frac{M_{BH}}{10^{8}M_{\odot}}$ (1)

We note that more complicated procedures than a simple bolometric corrections
from the intrinsic X-ray flux such as in terms of the Eddington ratio
($L/L_{\rm Edd}$) are sometimes used (e.g., Marconi et al., 2004; Lusso et
al., 2011). However, we prefer this simple approach, similar to what was done
in the BASS DR1, that can be reliably applied to all AGN.

We do not list individual errors for each $M_{\rm BH}$, $L_{\rm bol}$, and
$L/L_{\rm Edd}$ measurement, as they are dominated by the systematic
uncertainties in the scaling relations rather than the emission-line fitting
or velocity dispersion measurements which are typically $<$0.1 dex. Errors in
$M_{\rm BH}$ are of order 0.4-0.5 dex owing to systematic uncertainties in
virial and $\sigma_{*}$-based scaling relations (e.g., McLure & Dunlop, 2002;
Vestergaard & Peterson, 2006; Ricci et al., 2022). For $L_{\rm bol}$, the
scatter between BAT 14–195 keV luminosity and $L_{5100}$ was 0.46 dex in the
DR1 (Koss et al., 2017)

Efforts are currently underway for future BASS surveys to better calibrate the
bolometric correction with AGN source properties and estimate its intrinsic
reliability. A large HST program (${>}$100) AGN is currently underway
obtaining high spatial resolution near UV (${<}$3000 Å) imaging of the AGN
emission, combined with simultaneous measurement of the AGN emission in the
X-rays and UV/optical from Swift, with ground based imaging in $griz$.

A summary of the survey completeness in BH mass measurements for unbeamed AGN
is provided in Table 14 separated by AGN type. Overall the completeness is
slightly higher for Sy1 and Sy1.9 (${>}96\%$) than for velocity dispersion
measurements (${>}93\%$). Outside of the Galactic plane ($\lvert
b\rvert{>}10^{\circ}$) the survey completeness rises to $98\%$ for all
unbeamed AGN because of the typically lower extinction in these regions.
Finally, for beamed AGN with broad lines (BZQ) the measured BH masses (Table
14) and completeness are somewhat lower, but still the majority (91%).

A summary of the typical BH masses, bolometric luminosities, Eddington ratios,
and X-ray column densities is provided in Table 14 and Table 15 for unbeamed
and beamed AGN, respectively.

Table 13: Summary of Best Black Hole Mass Method

Best BH Mass Method | Count
---|---
$\sigma_{\star}$ | 344
H$\beta$ | 305
Lit. | 62
H$\alpha$ ($N_{\rm H}$$>10^{22}$ cm-2) | 37
H$\alpha$ | 13
Mg ii $\lambda 2798$ | 11
C iv $\lambda 1549$ | 10
C iv $\lambda 1549$ ($N_{\rm H}$$>10^{22}$ cm-2) | 4
Mg ii $\lambda 2798$ ($N_{\rm H}$$>10^{22}$ cm-2) | 3
H$\beta$ ($N_{\rm H}$$>10^{22}$ cm-2) | 1
Total | 790

Note. — The best BH mass measurement provided in the catalog. See subsection
4.2 for details.

Figure 8: Left: histogram of the BH mass estimates excluding broad-line
measurements in X-ray-obscured AGN ($N_{\rm H}$${>}10^{22}$ cm-2). Right:
Histogram of the BH mass estimates in the small number of X-ray-obscured AGN
with only broad-line measurements. While many of these AGN do have BH masses
consistent with the other unobscured distribution (e.g. $>10^{7}$ $M_{\odot}$)
there is a larger fraction with low masses ($<10^{7}$ $M_{\odot}$), which may
be significantly underestimated.

##  5 Summary

We have presented an overview of the BASS DR2 survey with 1449 optical
spectra, of which 1182 are released for the first time, for the 858 hard-X-
ray-selected AGN in the Swift BAT 70-month sample. With this first DR2 catalog
release we provide the following:

  * •

A revised catalog based on optical and NIR spectroscopic follow-up that
identifies all of 858 among unknown sources above ($\lvert
b\rvert{>}3^{\circ}$) or below $A_{\mathrm{V}}$=5 mag excluding only 7 unknown
sources deep within the Galactic plane at high extinction. We have included
new identifications of 17 Galactic sources.

  * •

We have further classified our sources by AGN type based on the presence of
broad lines (e.g. Sy1, Sy1.9, Sy2) as well as beamed and lensed AGN. We have
further provided important catalogs for population studies including dual AGN,
weakly associated AGN, and multiple weak confused sources within the BAT beam.

  * •

A full master catalog summary of the 1449, instrumental settings, their
reductions, and observing conditions. With this we have provided a master
catalog of redshifts, distances, bolometric luminosities, and BH masses.

  * •

Overall the completion for the survey is 99.9% in redshift outside the extreme
regions in the Galactic plane ($\lvert b\rvert{>}3^{\circ}$). In BH mass, the
survey is 98% complete using broad lines and velocity dispersions for unbeamed
AGN outside the Galactic plane ($\lvert b\rvert{>}10^{\circ}$). The final
catalog contains 47 new redshift measurements and 790 BH mass measurements.

Table 14: Summary of Unbeamed AGN Properties

Type | $N$ | $N$ | $z$ | N${}_{M_{\rm BH}}$ | N${}_{M_{\rm BH}}$ | % Meas $M_{\rm BH}$ | % Meas |  $\log$ $M_{\rm BH}$ |  $\log$ $L_{\rm bol}$ |  $\log$ $L/L_{\rm Edd}$ |  $\log$ $N_{\rm H}$
---|---|---|---|---|---|---|---|---|---|---|---
|  | $\lvert b\rvert>10^{\circ}$ |  |  | $\lvert b\rvert>10^{\circ}$ |  | $\lvert b\rvert>10^{\circ}$ | ($M_{\odot}$) | (${\rm\thinspace erg}{\rm\thinspace s}^{-1}\,$) |  | (cm-2)
(1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) | (11) | (12)
Sy1 | 359 | 318 | 0.050$\pm$0.003 | 350 | 311 | 97 | 98 | 7.81$\pm$0.04 | 44.87$\pm$0.04 | -1.17$\pm$0.03 | 20.0$\pm$0.05
Sy1.9 | 101 | 86 | 0.030$\pm$0.004 | 97 | 84 | 96 | 98 | 7.98$\pm$0.06 | 44.59$\pm$0.08 | -1.61$\pm$0.09 | 22.28$\pm$0.13
Sy2 | 292 | 259 | 0.029$\pm$0.003 | 275 | 253 | 94 | 98 | 8.06$\pm$0.04 | 44.50$\pm$0.04 | -1.71$\pm$0.04 | 23.27$\pm$0.05
Total | 752 | 663 | 0.038$\pm 0.002$ | 722 | 648 | 96 | 98 | 7.96$\pm$0.03 | 44.67$\pm$0.03 | -1.42$\pm$0.03 | 21.98$\pm$0.06

Note. — Summary of the medians and standard error of the median for different
populations of unbeamed AGN. Column (1): AGN optical type based on the
presence of broad H$\beta$ and H$\alpha$. Column (2): Total for the whole
sample. Column (3): total excluding the Galactic plane region $\lvert
b\rvert<10^{\circ}$ where high optical extinction makes measurements more
difficult. Column (4): median redshift from optical lines. Columns (5–8):
number of unique AGN with $M_{\rm BH}$ measurements and excluding the Galactic
plane region $\lvert b\rvert<10^{\circ}$ where high optical extinction makes
measurements more difficult. Also listed as percentages. Columns (9-12):
median $M_{\rm BH}$, $L_{\rm bol}$, $L/L_{\rm Edd}$, and, $\log(N_{\rm H}/{\rm
cm}^{-2})$ for the sample.

Table 15: Summary of Beamed AGN Properties

Type | $N$ |  $N$, $\lvert b\rvert>10^{\circ}$ | $z$ | $N_{M_{\rm BH}}$ | % Meas $M_{\rm BH}$ |  $\log$ $M_{\rm BH}$ |  $\log$ $L_{\rm bol}$ |  $\log$ $L/L_{\rm Edd}$ |  $\log$ $N_{\rm H}$
---|---|---|---|---|---|---|---|---|---
(1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10)
BZQ | 74 | 63 | 0.88$\pm$0.12 | 67 | 91 | 8.83$\pm$0.09 | 47.66$\pm$0.16 | 0.38$\pm$0.12 | 20$\pm$0.11
BZB | 22 | 18 | 0.13$\pm$0.02 |  |  |  | 45.81$\pm$0.12 |  | 20.57$\pm$0.12
BZG | 8 | 6 | 0.07$\pm$0.02 |  |  |  | 45.11$\pm$0.20 |  | 20.81$\pm$0.11
Sy1/Lense | 1 | 1 | 0.65 | 1 | 100 | 8.79 | 47.18 | 0.21 | 20
BZQ/Lense | 1 | 0 | 2.51 |  |  |  | 49.49 |  | 22.77
Total | 106 | 88 | 0.33$\pm$0.10 | 68 |  | 8.83$\pm$0.09 | 46.53$\pm$0.14 | 0.38$\pm$0.12 | 20.54$\pm$0.08

Note. — Summary of the medians and standard error of the median for different
populations of beamed and/or lensed AGN. (1) AGN optical type based on
presence of broad lines (BZQ), only host galaxy features lacking broad lines
(BZG), or traditional continuum-dominated blazars with no emission lines
(BZB), or lensing. (2) Total for the whole sample and excluding the Galactic
plane region $\lvert b\rvert<10^{\circ}$ where high optical extinction makes
measurements more difficult. (4) Median redshift from optical lines. (5–6)
Number of unique AGN with $M_{\rm BH}$ measurements and percentages. (7–10)
Median $M_{\rm BH}$, $L_{\rm bol}$, $L/L_{\rm Edd}$, and, $\log(N_{\rm H}/{\rm
cm}^{-2})$ for the sample.

##  6 Acknowledgment

We thank the reviewer for the constructive comments that helped us improve the
quality of this paper.

BASS/DR2 was made possible through the coordinated efforts of a large team of
astronomers, supported by various funding institutions, and using a variety of
facilities.

We acknowledge support from NASA through ADAP award NNH16CT03C (M.K.); the
Israel Science Foundation through grant number 1849/19 (B.T.); the European
Research Council (ERC) under the European Union’s Horizon 2020 research and
innovation program, through grant agreement number 950533 (B.T.); FONDECYT
Postdoctorado 3180506 (F.R.) and 3210157 (A.R.); FONDECYT Regular 1190818
(E.T., F.E.B.) and 1200495 (E.T.,F.E.B); ANID grants CATA-Basal AFB-170002,
ACE210002, and FB210003 (C.R., F.R., E.T., F.E.B., and E.C.); ANID Anillo
ACT172033 (E.T.); and Millennium Science Initiative Program – ICN12_009 (FEB);
an ESO fellowship (M.H., J.M.); Fondecyt Iniciacion grant 11190831 (C.R.).
K.O. acknowledges support from the National Research Foundation of Korea
(NRF-2020R1C1C1005462) and the Japan Society for the Promotion of Science
(JSPS, ID: 17321); M.B. acknowledges support from the YCAA Prize Postdoctoral
Fellowship; R.R. thanks CNPq (311223/2020-6), CAPES and FAPERGS
(16/2551-0000251-7 and 19/2551-0001750-2). This work was performed in part at
Aspen Center for Physics, which is supported by National Science Foundation
grant PHY-1607611.

We also acknowledge the following people who assisted in acquiring the Palomar
observations presented herein: Dave Alexander, Roberto Assef, Rosamaria
Carraro, Alison Dugas, Peter Eisenhardt, Clarke Esmerian, Carla Fuentes, Felix
Fuerst, Maya Fuller, Daniel Gawerc, David Girou, Ana Glidden, Matthew Graham,
Claire Greenwell, Brian Grefenstette, Marianne Heida, Hyunsung Jun, Peter
Kosec, Stephanie LaMassa, Jeff Maggio, Alejandra Melo, Catalina-Ana Miritescu,
Wenli Mo, Eric Mukherjee, Gael Noirot, Antonija Oklopčić, Sean Pike, Joseph
Simon, Tawny Sit, Navin Sridhar, Aaron Stemo, Becky Tang, Thomas Venville,
Jingyi Wang, and Dominika Wylezalek. We acknowledge financial contribution
from Joanna Wall Muir and the California Institute of Technology’s Student
Faculty Program to assist in the Palomar observations for Tea Freedman-
Susskind, Feiyang Liu, Milan Robertson, Yerong Xu, and Emily Zhang. We
acknowledge the work that Swift BAT team has done to make this project
possible.

We acknowledge the various telescopes used in this paper. We are tremendously
thankful to all the observing and support staff in all the observatories, and
their headquarters, for their great assistance in planning and conducting the
observations that made BASS/DR2 possible. Specifically, BASS/DR2 is based on
the following:
(1) Observations collected at the European Organisation for Astronomical
Research in the Southern Hemisphere under 34 ESO programs: 60.A-9024(A),
60.A-9421(A), 062.H-0612(A), 086.B-0135(A), 089.B-0951(A), 089.B-0951(B),
090.A-0830(A), 090.D-0828(A), 091.B-0900(B), 091.C-0934(B), 092.B-0083(A),
093.A-0766(A), 094.B-0321(A), 095.B-0059(A), 098.A-0062, 098.A-0635(B),
098.B-0551(A), 099.A-0403(A+B), 099.A-0442(A), 099.B-0785(A), 0101.A-0765(A),
0101.B-0456(B), 0101.B-0739(A), 0102.A-0433(A), 0102.B-0048, 0103.A-0521(A),
0103.B-0566(A), 0103.A-0777(A), 0104.A-0353(A), 0104.B-0959(A),
0106.A-0521(A), 385.B-1035(A), 2100.B-5018(B), and 60.A-9100(J).

(2) Data obtained with the Hale 200-inch telescope at Palomar observatory,
including five dedicated Yale programs: 2017B/Y04, 2018A/Y03, 2018B/Y04,
2019A/Y03, and 2019B/Y04 (PI: M. Powell). Additional data were obtained as
part of Caltech runs including 2014B/P05, 2015A/P04, 2015B/P06, 2016A/P06,
2016B/P04, 2017A/P13, 2017B/P01, 2018A/P15, 2018B/P02, 2019A/P18, 2019B/P11,
2020A/P14, 2020B/P19 (PI: F. Harrison) and also JPL runs including 2016B/J12,
2017A/J07, 2017B/J15 2019B/J09, 2019A/J06, 2019B/J19, 2020A/J11, 2020B/J04
(PI: D. Stern).

(3) Observations obtained at the Southern Astrophysical Research (SOAR)
telescope, which is a joint project of the Ministério da Ciência, Tecnologia e
Inovaç$\sim$oes (MCTI/LNA) do Brasil, the US National Science Foundation’s
NOIRLab, the University of North Carolina at Chapel Hill (UNC), and Michigan
State University (MSU). These include from CNTAC (CN2018A-104, CN2018B-83) and
NOIRLab program 2012A-0463 (PI M. Trippe).

(4) Observations at Kitt Peak National Observatory at NSF’s NOIRLab (NOIRLab
Prop. ID 52, 2946; PI: F. Bauer), which is managed by the Association of
Universities for Research in Astronomy (AURA) under a cooperative agreement
with the National Science Foundation. We are honored to be permitted to
conduct astronomical research on Iolkam Du’ag (Kitt Peak), a mountain with
particular significance to the Tohono O’odham.

(5) Data gathered with the 6.5 m Magellan Telescopes (CN2019A-70 and
CN2019B-77) and the 2.5 m Dupont Telescope (CN2016A-80) located at Las
Campanas Observatory, Chile. Support for the design and construction of the
Magellan Echellette Spectrograph was received from the Observatories of the
Carnegie Institution of Washington, the School of Science of the Massachusetts
Institute of Technology, and the National Science Foundation in the form of a
collaborative Major Research Instrument grant to Carnegie and MIT
(AST0215989).

(6) Data obtained at the W.M. Keck Observatory, which is operated as a
scientific partnership among the California Institute of Technology, the
University of California, and the National Aeronautics and Space
Administration. The Observatory was made possible by the generous financial
support of the W. M. Keck Foundation. The authors wish to recognize and
acknowledge the very significant cultural role and reverence that the summit
of Maunakea has always had within the indigenous Hawaiian community. We are
most fortunate to have the opportunity to conduct observations from this
mountain.

(7) Data obtained as part of the various stages of the Sloan Digital Sky
Survey (SDSS-I/II, III, and IV). Funding for the SDSS has been provided by the
Alfred P. Sloan Foundation, the US Department of Energy Office of Science, and
the Participating Institutions. SDSS acknowledges support and resources from
the Center for High Performance Computing at the University of Utah. The SDSS
website is www.sdss.org. The most recent generation of the SDSS we benefited
from, SDSS-IV, is managed by the Astrophysical Research Consortium for the
Participating Institutions of the SDSS Collaboration including the Brazilian
Participation Group, the Carnegie Institution for Science, Carnegie Mellon
University, Center for Astrophysics — Harvard & Smithsonian, the Chilean
Participation Group, the French Participation Group, Instituto de Astrofísica
de Canarias, The Johns Hopkins University, Kavli Institute for the Physics and
Mathematics of the Universe (IPMU) / University of Tokyo, the Korean
Participation Group, Lawrence Berkeley National Laboratory, Leibniz Institut
für Astrophysik Potsdam (AIP), Max-Planck-Institut für Astronomie (MPIA
Heidelberg), Max-Planck-Institut für Astrophysik (MPA Garching), Max-Planck-
Institut für Extraterrestrische Physik (MPE), National Astronomical
Observatories of China, New Mexico State University, New York University,
University of Notre Dame, Observatário Nacional / MCTI, The Ohio State
University, Pennsylvania State University, Shanghai Astronomical Observatory,
United Kingdom Participation Group, Universidad Nacional Autónoma de México,
University of Arizona, University of Colorado Boulder, University of Oxford,
University of Portsmouth, University of Utah, University of Virginia,
University of Washington, University of Wisconsin, Vanderbilt University, and
Yale University.

This research has made use of the NASA/IPAC Extragalactic Database (NED),
which is operated by the Jet Propulsion Laboratory, California Institute of
Technology, under contract with the National Aeronautics and Space
Administration. This research has made use of the SIMBAD database, operated at
CDS, Strasbourg, France.

A significant part of the BASS observations and work took place during the
COVID-19 crisis. We thank the health care experts in communities around the
world, for their tireless efforts to keep us all as safe and healthy as
possible.

##  Appendix A Comparison to DR1 and Past Surveys

Here we provide a comparison to the 641 optical spectroscopic measurements
from the BASS DR1 including redshifts, AGN classification, and BH mass
measurements as well as past measurements in the literature. ,

###  A.1 Beamed AGN Changes in DR2

Here we provide a list of all beamed AGN that are newly identified or changed
in DR2 in subsection A.1 compared to the DR1. Example spectra for the various
classes (e.g., BZB, BZG, BZQ) are found in Figure 9.

Table 16: Beamed AGN Changes in DR2

BAT ID | Swift Name | DR1 ClassaaBeamed AGN type in BASS DR1 (Koss et al., 2017). | DR2 Type | Ref.
---|---|---|---|---
30 | SWIFT J0042.9+3016B |  | BZQ | P19
33 | SWIFT J0048.8+3155 | BZB | Sy2 | P19
59 | SWIFT J0113.8+2515 |  | BZQ | P19
140 | SWIFT J0241.3-0816 | BZU | Sy2 | P19
170 | SWIFT J0312.9+4121 | BZU | Sy1 | T78
173 | SWIFT J0319.7+4132 | BZU | Sy2 | P19
178 | SWIFT J0326.0-5633 |  | BZG | P19
226 | SWIFT J0433.0+0521 | BZU | Sy1 | P19
273 | SWIFT J0519.5-3140 | BZU | Sy1 | A19
277 | SWIFT J0525.3-4600 | BZQ | Sy2 | P19
323 | SWIFT J0225.0+1847 |  | BZQ | P19
359 | SWIFT J1959.6+6507 |  | BZB | P19
377 | SWIFT J0733.9+5156 |  | BZG | P19
660 | SWIFT J1310.9-5553 |  | BZQ | P19
671 | SWIFT J1325.4-4301 | BZU | Sy2 | P19
690 | SWIFT J1347.1+7325 |  | BZQ | P19
761 | SWIFT J1943.5+2120 |  | BZQ | P19
780 | SWIFT J1145.6-6956 |  | BZQ | P19
787 | SWIFT J1557.8-7913 | BZU | Sy2 | P19
876 | SWIFT J1719.7+4900 | BZU | Sy1.9 | P19
897 | SWIFT J1458.9+7143 |  | BZQ | P19
906 | SWIFT J1742.1-6054 | BZU | Sy1 | B16
1082 | SWIFT J2033.4+2147 |  | BZQ | P19
1105 | SWIFT J2117.5+5139 |  | BZQ | P19
1142 | SWIFT J2209.4-4711 | BZU | Sy1.9 | P19
1181 | SWIFT J2303.1-1837 | BZU | Sy1 | P19

Note. — Column descriptions are the same as in Table 1, unless otherwise
noted.

References. — A19: Angioni et al. (2019); B16: Bassani et al. (2016); P19:
Paliya et al. (2019); T78: Tzanetakis et al. (1978).

###  A.2 AGN classification

Overall, there are 168 DR2 AGN that we provided revised or the first
classification of AGN type based on our measurements. For comparison, we first
look at the 641 DR1 AGN types compared to overlapping DR2 AGN types. There are
10% changes (64/641). This includes 52 reclassifications from Sy2 to Sy1.9 or
Sy1, or from Sy1.9 to Sy1 based on the detection of broad lines that were not
detected in DR1 spectra. Conversely, 12 spectra change from Sy1 to Sy1.9 or
Sy2 or from Sy1.9 to Sy2. This shift largely reflects the higher-quality
spectra in terms of resolution and signal-to-noise ratio compared to the
archival DR1, which used much smaller telescopes and lower spectral
resolutions rather than ”bona fide” AGN that have undergone changes. The ”bona
fide” changing optical type AGN are part of a future study (Temple, M. et al.
2022, in preparation). Among the 216 AGN which were not part of the DR1
release, roughly half have their first or revised classifications (48%,
103/216). This is compared to the most recent 105-month survey (Oh et al.,
2018) which includes updates from SIMBAD and NED. From these 103, 72
measurements are to previously unknown AGN without available optical
spectroscopy or classification.

###  A.3 Redshifts

We compare the redshifts from the 599 DR1 to the revised measurements from
spectroscopy in DR2. Among the low-redshift sample ($z{<}0.3$) the agreement
is excellent, with no differences larger than 1000 ${\rm\thinspace
km}{\rm\thinspace s}^{-1}\,$. At higher redshifts ($0.3{>}z{>}1$) the median
offset increases ($\lvert z_{DR2}-z_{DR1}\rvert{=}$ 157 ${\rm\thinspace
km}{\rm\thinspace s}^{-1}\,$), and finally increases to 1180 ${\rm\thinspace
km}{\rm\thinspace s}^{-1}\,$at $z{>}1$ owing to the use of the intrinsically
broad lines of Mg ii $\lambda 2798$ and C iv $\lambda 1549$ for the derivation
of the redshift.

##  Appendix B Example Spectra

Here we provide example spectra of various classes of AGN and telescope
setups. Example spectra for each AGN will be provided at the BASS
website.555https://www.bass-survey.com/

Figure 9: Figure showing the spectral classification of beamed sources based
on the presence of broad lines (BZQ, top), traditional continuum-dominated
blazars with no emission lines or host galaxy features (BZB, middle), or only
host galaxy features lacking broad lines (BZG, bottom).

Figure 10: Figure showing examples of spectral setups not shown earlier in the
text excluding the archival observations. A spectrum from the du Pont
telescope with the Bollens & Chivens spectrograph with the 300 lines/mm
grating is shown in the top panel, a spectrum from the VLT with the FORS2
instrument is shown in the middle panel, and a spectrum with Keck using the
LRIS instrument is shown in the bottom panel.

Figure 11: Figure showing examples of high-resolution spectral setups not
shown earlier in the text excluding the archival observations. A spectrum
taken at the Palomar telescope with the Doublespec instrument with the 1200
lines/mm grating is shown on top, with a spectrum from SOAR with 1200 lines/mm
grating using the Goodman instrument in middle, and finally an echelle
spectrum from Magellan using the MAGE instrument.

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