We present the active galactic nucleus 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 hardXrayselected AGNs in the Swift BAT 70month sample. The majority of the spectra 8011449 55 are newly obtained from Very Large Telescope VLTXshooter or PalomarDoublespec. Many of the spectra have both higher resolution R gt 2500 N  450 andor very wide wavelength coverage 320010000  N  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 AGNs 100 858858 with 99.8 having redshift measurements 857858 and 96 completion in black hole mass estimates of unbeamed AGNs 722752. This AGN sample represents a unique census of the brightest hardXrayselected AGNs in the sky spanning many orders of magnitude in Eddington ratio LL SUBEddSUB  10SUP5SUP100 black hole mass M SUBBHSUB  10SUP5SUP10SUP10SUP M SUBSUB and AGN bolometric luminosity L SUBbolSUB  10SUP40SUP10SUP47SUP erg sSUP1SUP .
['X-ray active galactic nuclei', 'Active galactic nuclei', 'Seyfert galaxies', 'X-ray quasars', 'X-ray surveys', 'Surveys', 'Sky surveys', 'Galaxy spectroscopy', '2035', '16', '1447', '1821', '1824', '1671', '1464', '2171', 'Astrophysics - Astrophysics of Galaxies', 'Astrophysics - High Energy Astrophysical Phenomena']
BASS. XXII. The BASS DR2 AGN Catalog and Data
{'No Header': 'D/r.pc/a.pc/f.pc/t.pc /v.pc/e.pc/r.pc/s.pc/i.pc/o.pc/n.pc J/u.pc/l.pc/y.pc 27, 2022 Typeset using L A T E X default style in AASTeX631', 'BASS XXII: The BASS DR2 AGN Catalog and Data': "M/i.pc/c.pc/h.pc/a.pc/e.pc/l.pc J. K/o.pc/s.pc/s.pc, 1, 2 C/l.pc/a.pc/u.pc/d.pc/i.pc/o.pc R/i.pc/c.pc/c.pc/i.pc, 3, 4 B/e.pc/n.pc/n.pc/y.pc T/r.pc/a.pc/k.pc/h.pc/t.pc/e.pc/n.pc/b.pc/r.pc/o.pc/t.pc, 5 K/y.pc/u.pc/s.pc/e.pc/o.pc/k.pc O/h.pc, 6, 7, 8 J/a.pc/k.pc/o.pc/b.pc S. /d.pc/e.pc/n.pc B/r.pc/o.pc/k.pc, 9, 10 J/u.pc/l.pc/i.pc/a.pc/n.pc E. M/e.pc/j.pc/iacute.pc/a.pc-R/e.pc/s.pc/t.pc/r.pc/e.pc/p.pc/o.pc, 11 D/a.pc/n.pc/i.pc/e.pc/l.pc S/t.pc/e.pc/r.pc/n.pc, 12 G/e.pc/o.pc/r.pc/g.pc/e.pc C. P/r.pc/i.pc/v.pc/o.pc/n.pc, 13, 14 E/z.pc/e.pc/q.pc/u.pc/i.pc/e.pc/l.pc T/r.pc/e.pc/i.pc/s.pc/t.pc/e.pc/r.pc, 15 M/e.pc/r.pc/e.pc/d.pc/i.pc/t.pc/h.pc C. P/o.pc/w.pc/e.pc/l.pc/l.pc, 16 R/i.pc/c.pc/h.pc/a.pc/r.pc/d.pc M/u.pc/s.pc/h.pc/o.pc/t.pc/z.pc/k.pc/y.pc, 17 F/r.pc/a.pc/n.pc/z.pc E. 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B/adieresis.pc/r.pc, 9 G/e.pc/o.pc/r.pc/g.pc/e.pc B/e.pc/c.pc/k.pc/e.pc/r.pc, 23 P/a.pc/t.pc/r.pc/i.pc/c.pc/i.pc/a.pc B/e.pc/s.pc/s.pc/i.pc/e.pc/r.pc/e.pc, 15 L/e.pc/o.pc/n.pc/a.pc/r.pc/d.pc B/u.pc/r.pc/t.pc/s.pc/c.pc/h.pc/e.pc/r.pc, 24 T/u.pc/r.pc/g.pc/a.pc/y.pc C/a.pc/g.pc/l.pc/a.pc/r.pc, 25 E/n.pc/r.pc/i.pc/c.pc/o.pc C/o.pc/n.pc/g.pc/i.pc/u.pc, 26 P/h.pc/i.pc/l.pc E/v.pc/a.pc/n.pc/s.pc, 27 F/i.pc/o.pc/n.pc/a.pc H/a.pc/r.pc/r.pc/i.pc/s.pc/o.pc/n.pc, 28 M/a.pc/r.pc/i.pc/a.pc/n.pc/n.pc/e.pc H/e.pc/i.pc/d.pc/a.pc, 29 K/o.pc/h.pc/e.pc/i.pc I/c.pc/h.pc/i.pc/k.pc/a.pc/w.pc/a.pc, 30, 31, 32 N/i.pc/k.pc/i.pc/t.pc/a.pc K/a.pc/m.pc/r.pc/a.pc/j.pc, 28 I/s.pc/a.pc/b.pc/e.pc/l.pc/l.pc/a.pc L/a.pc/m.pc/p.pc/e.pc/r.pc/t.pc/i.pc, 33 F/a.pc/b.pc/i.pc/o.pc P/a.pc/c.pc/u.pc/c.pc/c.pc/i.pc, 34, 35 F/e.pc/d.pc/e.pc/r.pc/i.pc/c.pc/a.pc R/i.pc/c.pc/c.pc/i.pc, 15, 36 R/o.pc/g.pc/eacute.pc/r.pc/i.pc/o.pc R/i.pc/f.pc/f.pc/e.pc/l.pc, 37 A/l.pc/e.pc/j.pc/a.pc/n.pc/d.pc/r.pc/a.pc F. R/o.pc/j.pc/a.pc/s.pc, 38 K/e.pc/v.pc/i.pc/n.pc S/c.pc/h.pc/a.pc/w.pc/i.pc/n.pc/s.pc/k.pc/i.pc, 39 M/a.pc/t.pc/t.pc/h.pc/e.pc/w.pc T/e.pc/m.pc/p.pc/l.pc/e.pc, 40 C. M/e.pc/g.pc/a.pc/n.pc U/r.pc/r.pc/y.pc, 22 S/y.pc/l.pc/v.pc/a.pc/i.pc/n.pc V/e.pc/i.pc/l.pc/l.pc/e.pc/u.pc/x.pc, 17 /a.pc/n.pc/d.pc J/o.pc/n.pc/a.pc/t.pc/h.pc/a.pc/n.pc W/i.pc/l.pc/l.pc/i.pc/a.pc/m.pc/s.pc 17  \n1 Eureka Scientific, 2452 Delmer Street, Suite 100, Oakland, CA 94602-3017, USA  \n2 Space Science Institute, 4750 Walnut Street, Suite 205, Boulder, CO 80301, USA  \n3 Núcleo de Astronomía de la Facultad de Ingeniería, Universidad Diego Portales, Av. Ejército Libertador 441, Santiago 22, Chile  \n4 Kavli Institute for Astronomy and Astrophysics, Peking University, Beĳing 100871, People's Republic of China 5  \nSchool of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978, Israel  \n6 Korea Astronomy & Space Science institute, 776, Daedeokdae-ro, Yuseong-gu, Daejeon 34055, Republic of Korea  \n7 Department of Astronomy, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan  \n8 JSPS Fellow  \n9 Institute for Particle Physics and Astrophysics, ETH Zürich, Wolfgang-Pauli-Strasse 27, CH-8093 Zürich, Switzerland  \n10 Argelander Institute for Astronomy, Auf dem Hügel 71, D-53231, Bonn, Germany  \n11 European Southern Observatory, Casilla 19001, Santiago 19, Chile  \n12 Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, MS 169-224, Pasadena, CA 91109, USA  \n13 National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903, USA  \n14 Department of Astronomy, University of Florida, P.O. Box 112055, Gainesville, FL 32611, USA  \n15 Instituto de Astrofísica, Facultad de Física, Pontificia Universidad Católica de Chile, Casilla 306, Santiago 22, Chile  \n16 Kavli Institute of Particle Astrophysics and Cosmology, Stanford University, 452 Lomita Mall, Stanford, CA 94305, USA  \n17 Department of Astronomy, University of Maryland, College Park, MD 20742, USA  \n18 Instituto de Astrofísica and Centro de Astroingeniería, Facultad de Física, Pontificia Universidad Católica de Chile, Casilla 306, Santiago 22, Chile  \n19 Millennium Institute of Astrophysics (MAS), Nuncio Monse GLYPH<24> nor Sótero Sanz 100, Providencia, Santiago, Chile  \n20 Space Science Institute, 4750 Walnut Street, Suite 205, Boulder, Colorado 80301, USA  \n21 Department of Physics and Astronomy, Dartmouth College, 6127 Wilder Laboratory, Hanover, NH 03755, USA  \nYale Center for Astronomy & Astrophysics and Department of Physics, Yale University, P.O. Box 208120, New Haven, CT 06520-8120, USA  \n23 Department of Physics & Astronomy, University of California, Riverside, CA 92521, USA  \n24 Leiden Observatory, P.O. Box 9513, 2300 RA, Leiden, the Netherlands  \n25 Leiden Observatory, PO Box 9513, 2300 RA, Leiden, the Netherlands  \n26 Departamento de Astronomía, Universidad de Chile, Camino del Observatorio 1515, Las Condes, Santiago, Chile  \n27 Department of Physics and Astronomy, University of Leicester, Leicester, LE1 7RH, UK  \n28 Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125, USA  \n29 European Southern Observatory, Karl-Schwarzschild-Str. 2, D-85748 Garching bei München, Germany  \n30 Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Sendai 980-8578, Japan  \n31 Astronomical Institute, Graduate School of Science Tohoku University, 6-3 Aramaki, Aoba-ku, Sendai 980-8578, Japan  \n32 Max-Planck-Institut für extraterrestrische Physik (MPE), Giessenbachstrasse 1, D-85748 Garching bei Müunchen, Germany  \n33 Centro de Astrobiología (CAB), CSIC-INTA, Cra. de Ajalvir Km. 4, E-28850 Torrejón de Ardoz, Madrid, Spain  \n34 Center for Astrophysics, Harvard & Smithsonian, Cambridge, MA 02138, USA  \n35 Black Hole Initiative, Harvard University, Cambridge, MA 02138, USA  \n36 Dipartimento di Fisica e Astronomia, Università di Bologna, via Gobetti 93/2, 40129 Bologna, Italy  \n37 Departamento de Astronomia, Instituto de Física, Universidade Federal do Rio Grande do Sul, CP 15051, 91501-970, Porto Alegre, RS, Brazil  \n38 Centro de Astronomía (CITEVA), Universidad de Antofagasta, Avenida Angamos 601, Antofagasta, Chile  \n39 Modulos AG, Technoparkstrasse 1, CH-8005 Zurich, Switzerland  \n40 Universidad Diego Portales, Av. Ejército Libertador 441, Santiago 8370109, Chile  \n22  \nCorresponding author: Michael Koss  \nmike.koss@eurekasci.com", 'K/o.pc/s.pc/s.pc /e.pc/t.pc /a.pc/l.pc.': "Table 13. Summary of Best Black Hole Mass Method  \nN/o.pc/t.pc/e.pc-The best BH mass measurement pro- vided in the catalog. See subsection 4.2 for details.  \nFigure 8. Left: histogram of the BH mass estimates excluding broad-line measurements in X-ray-obscured AGN ( 𝑁 H ¡ 10 22 cm GLYPH<0> 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 GLYPH<12> ) there is a larger fraction with low masses ( GLYPH<159> 10 7 𝑀 GLYPH<12> ), which may be significantly underestimated.  \n<!-- image -->  \n- · Arevised catalog based on optical and NIR spectroscopic follow-up that identifies all of 858 among unknown sources above ( j 𝑏 j ¡ 3 GLYPH<14> ) or below 𝐴 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.\n- · 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.\n- · Afull 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.\n- · Overall the completion for the survey is 99.9% in redshift outside the extreme regions in the Galactic plane ( j 𝑏 j ¡ 3 GLYPH<14> ). In BH mass, the survey is 98% complete using broad lines and velocity dispersions for unbeamed AGN outside the Galactic plane ( j 𝑏 j ¡ 10 GLYPH<14> ). The final catalog contains 47 new redshift measurements and 790 BH mass measurements.  \nTable 14. Summary of Unbeamed AGN Properties  \nN/o.pc/t.pc/e.pc-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 𝛽 and H 𝛼 . Column (2): Total for the whole sample. Column (3): total excluding the Galactic plane region j 𝑏 j GLYPH<159> 10 GLYPH<14> where high optical extinction makes measurements more difficult. Column (4): median redshift from optical lines. Columns (5-8): number of unique AGN with 𝑀 BH measurements and excluding the Galactic plane region j 𝑏 j GLYPH<159> 10 GLYPH<14> where high optical extinction makes measurements more difficult. Also listed as percentages. Columns (9-12): median 𝑀 BH, 𝐿 bol , 𝐿 GLYPH<157> 𝐿 Edd , and, log ' 𝑁 H GLYPH<157> cm GLYPH<0> 2 ' for the sample.  \nTable 15. Summary of Beamed AGN Properties  \nN/o.pc/t.pc/e.pc-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 j 𝑏 j GLYPH<159> 10 GLYPH<14> where high optical extinction makes measurements more difficult. (4) Median redshift from optical lines. (5-6) Number of unique AGN with 𝑀 BH measurements and percentages. (7-10) Median 𝑀 BH , 𝐿 bol , 𝐿 GLYPH<157> 𝐿 Edd , and, log ' 𝑁 H GLYPH<157> cm GLYPH<0> 2 ' for the sample.", '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 GLYPH<24> 450) and/or very wide wavelength coverage (3200-10000 Å, 𝑁 GLYPH<24> 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 GLYPH<157> 𝐿 Edd=10 GLYPH<0> 5 -100), black hole mass ( 𝑀 BH=10 5 GLYPH<0> 10 10 𝑀 GLYPH<12> ), and AGN bolometric luminosity ( 𝐿 bol=10 40 GLYPH<0> 10 47 erg s GLYPH<0> 1 ).', '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).  \nLarger 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 ( GLYPH<24> 17000 GLYPH<14> 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.  \nHard 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 H ¡ 10 22 GLYPH<0> 10 25 cm GLYPH<0> 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 GLYPH<159> 0 GLYPH<149> 1), powerful AGN. The spectroscopic coverage in the SDSS for BAT AGN, is, however, only GLYPH<24> 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).  \nThe 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.  \n2020). 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).  \nIn 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).  \nIn 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 -𝜎 ★ relation of type 1 unobscured AGNs (Caglar in prep.). Throughout this work, we adopt Ω M = 0 GLYPH<149> 3, Ω Λ = 0 GLYPH<149> 7, and 𝐻 0 = 70 km s GLYPH<0> 1 Mpc GLYPH<0> 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 ( j 𝑏 j GLYPH<159> 10 GLYPH<14> ), 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.  \nGiven the large (FWHM=19.5 0 ) 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 GLYPH<24> 850 sources at j 𝑏 j ¡ 5 GLYPH<14> , (91% of the sky), so the likelihood of chance alignment of one unassociated source within the BAT beam is very small, GLYPH<24> 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.  \nThroughout this work, we refer to AGN as Sy1 (with optical broad H 𝛽 ), Sy1.9 (narrow H 𝛽 and broad H 𝛼 ), and Sy 2 (with narrow H 𝛽 and narrow H 𝛼 , 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.  \nK/o.pc/s.pc/s.pc /e.pc/t.pc /a.pc/l.pc.  \nTable 1. New 70-month AGN Counterparts in BASS DR2  \nN/o.pc/t.pc/e.pc-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 𝛽 ), Sy1.9 (narrow H 𝛽 and broad H 𝛼 ), and Sy 2 (with narrow H 𝛽 and H 𝛼 ). 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 𝛽 . For narrow-line sources, the redshift is based on emission-line fitting of [O /i.pc/i.pc/i.pc] 𝜆 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).  \nWe uncovered an additional 22 AGN among the remaining unidentified sources (Table 1). These sources were the brightest 2-10 keV sources within the 5 0 Swift BAT position error circle, and optical spectroscopy confirmed their AGN nature. The total sample then increases from 838 to 858 AGN. /one.sup Further details on the X-ray modeling of these newly detected AGN will be provided in C. Ricci, et al., (2022 in preparation).  \nA summary of the 17 sources that are newly classified as Galactic is provided in Table 2. For 10/17 sources, we determine the stellar nature based on optical spectroscopy, with the remaining sources being classified in recent publications.  \nThere 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 /i.pc/i.pc triplet spectral region (8450-8700 Å) and CO-band heads (2.29-2.51 𝜇 m).  \nIn 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 𝛼 emission at 𝑧 = 0. SWIFT J1213.2-6020 (aka IGR J12134-6015) was found to be located within 0 GLYPH<149> 00 3 of 2MASS J12132397-6015169 based on Chandra (Karasev et al. 2012).  \nFigure 1. Figure showing spectra of sources identified as Galactic based on emission or absorption lines at redshift zero.  \n<!-- image -->", '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 ( j 𝑏 j ¡ 3 GLYPH<14> ) 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).  \nMany 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.  \nThere 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 obs 2 GLYPH<0> 10 keV = 10 GLYPH<0> 13 erg cm GLYPH<0> 2 s GLYPH<0> 1 in flux that could be a likely counterpart. No observations of this source have been performed with Chandra, XMM-Newton, or NuSTAR.', 'BASS XXII: DR2 C/a.pc/t.pc/a.pc/l.pc/o.pc/g.pc': "Table 11. Newly Identified Redshifts  \nN/o.pc/t.pc/e.pc-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.  \nTable 12.  \nK/o.pc/s.pc/s.pc /e.pc/t.pc /a.pc/l.pc. Redshift Independent Distances  \n- 3. Broad-line H 𝛼 from Mejía-Restrepo et al. (2022) if 𝑁 H GLYPH<159> 10 22 cm GLYPH<0> 2 and broad-line H 𝛽 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.\n- 4. Broad-line Mg /i.pc/i.pc 𝜆 2798 followed by C /i.pc/v.pc 𝜆 1549 for high-redshift sources ( 𝑧¡ 0 GLYPH<149> 8) from Mejía-Restrepo et al. (2022) for those without broad-line H 𝛽 using the relation of Mejia-Restrepo et al. (2016).\n- 5. Stellar velocity dispersion measurements for all Sy1.9 and Sy2 AGN from Koss et al. (2022b). We calculated the BH mass, 𝑀 BH, using the 𝑀 BH GLYPH<0> 𝜎 GLYPH<3> relation of equation 13 from Kormendy & Ho (2013).\n- 6. If 𝑁 H ¡ 10 22 cm GLYPH<0> 2 , and if no velocity dispersion measurement is possible, broad-line H 𝛼 followed by broad-line H 𝛽 is used from Mejía-Restrepo et al. (2022). These final measurements should be used with caution because of the tendency to underestimate 𝑀 BH due to obscuration (e.g., Mejía-Restrepo et al. 2022; Ricci et al. 2022; Brok et al. 2022)  \nAsummary 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 𝛽 with a smaller number from literature measurements, broad H 𝛼 , broad H 𝛼 in X-rayobscured AGN ( 𝑁 H ¡ 10 22 cm GLYPH<0> 2 ), and Mg /i.pc/i.pc 𝜆 2798 or C /i.pc/v.pc 𝜆 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.  \nThe 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 Γ =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 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.  \nFor Eddington ratios we assume an Eddington luminosity consistent with solar metallicity:  \n𝐿 Edd = 1 GLYPH<149> 5 GLYPH<1> 10 46 erg s GLYPH<0> 1 𝑀 𝐵𝐻 10 8 𝑀 GLYPH<12> (1)  \nWe 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 GLYPH<157> 𝐿 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.  \nWe do not list individual errors for each 𝑀 BH, 𝐿 bol, and 𝐿 GLYPH<157> 𝐿 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 GLYPH<159> 0.1 dex. Errors in 𝑀 BH are of order 0.4-0.5 dex owing to systematic uncertainties in virial and 𝜎 GLYPH<3> -based scaling relations (e.g., McLure & Dunlop 2002; Vestergaard & Peterson 2006; Ricci et al. 2022). For 𝐿 bol, the scatter between BAT 14-195 keV luminosity and 𝐿 5100 was 0.46 dex in the DR1 (Koss et al. 2017)  \nEfforts 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 ( GLYPH<159> 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 .  \nA 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 ( j 𝑏 j ¡ 10 GLYPH<14> ) 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%).  \nA 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.", '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 ( GLYPH<24> GLYPH<159> 30 kpc), show small offsets in redshift ( GLYPH<159> 500 kms GLYPH<0> 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).  \nAsummaryof bright dual AGN in the sample can be found in Table 4. 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 obs 14 GLYPH<0> 195 keV ¡ 5 GLYPH<2> 10 GLYPH<0> 12 erg cm GLYPH<0> 2 s GLYPH<0> 1 which corresponds to the faintest detected sources in the sky by BAT rather than the median sensitivity 𝐹 obs 14 GLYPH<0> 195 keV ¡ 1 GLYPH<149> 03 GLYPH<2> 10 GLYPH<0> 11 erg cm GLYPH<0> 2 s GLYPH<0> 1 . We assume 𝐹 obs 14 GLYPH<0> 195 keV / 𝐹 in 2 GLYPH<0> 10 keV for this calculation, and Γ =1.8, which is consistent at 𝑁 H GLYPH<159> 10 23 GLYPH<149> 5 cm GLYPH<0> 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.  \nK/o.pc/s.pc/s.pc /e.pc/t.pc /a.pc/l.pc.  \nTable 5. Weakly Associated Counterparts in DR2  \nN/o.pc/t.pc/e.pc-Column descriptions are the same as in Table 1, unless otherwise noted.', '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 ( GLYPH<159> 500 kms GLYPH<0> 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.  \nHere we provide a list of multiple soft X-ray AGN that are detected within the BAT beam but are weakly associated ( GLYPH<24> 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.', '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 obs 14 GLYPH<0> 195 keV GLYPH<159> 10 GLYPH<149> 3 GLYPH<2> 10 GLYPH<0> 12 erg cm GLYPH<0> 2 s GLYPH<0> 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 GLYPH<149> 0041) and the background galaxy ESO 138-1 ( 𝑧 = 0 GLYPH<149> 0091).', '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.', '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  \nK/o.pc/s.pc/s.pc /e.pc/t.pc /a.pc/l.pc.  \nTable 7. DR2 Instrument Setups  \nN/o.pc/t.pc/e.pc-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.  \nor higher-resolution gratings with narrower wavelength coverage. Repeat observations were done if the S/N of the broad Balmer lines (H 𝛽 or H 𝛼 ) 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. /two.sup  \nA 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 GLYPH<159> 𝑏 GLYPH<159> 3 GLYPH<14> ), primarily to determine the first redshift and AGN type.  \nThe 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': 'We provide the following key parameters when possible for each individual spectrum (subsection 8):  \n- 1. BAT ID: Catalog ID in the BAT survey. /three.sup\n- 2. Telescope, diameter, instrument : Name of observatory, its diameter, and instrument used.\n- 3. File and File red : Name of associated fits spectral file. For telescopes with both a blue and red side, two spectra are listed.\n- 4. Flags : Any associated flags with calibration or spectral extraction. Star: indicates foreground stellar contamination, that a very nearby star ( GLYPH<159> 2 00 ) 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.\n- 5. Date : UT date of observation.\n- 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.\n- 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.\n- 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.\n- 9. Slit : Slit width in 00 . For telescopes with both a blue and red side, two widths are listed with the blue side first.\n- 10. Slit length : Extraction length along the slit in 00 . 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.', '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.', '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 GLYPH<149> 00 5 slit, This setup provided resolutions of GLYPH<24> 4.4 Å and GLYPH<24> 5.8 Å FWHM, over the GLYPH<24> 3150-5650 Å (blue) and GLYPH<24> 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 00 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.  \nA 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 GLYPH<0> 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', '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 GLYPH<0> 1 grating and GG455 blocking filter or 600 lines mm GLYPH<0> 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 GLYPH<0> 1 or 1200 lines mm GLYPH<0> 1 grating. Nearly all observations were done with a 1 GLYPH<149> 00 2 slit with just two sources done with a 0 GLYPH<149> 00 45 slit, because of the very low velocity dispersions. All sources were extracted optimally, with typically slit lengths of 4 GLYPH<149> 00 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 00 slit, the 300 lines mm GLYPH<0> 1 grating covering 3000-9070 Å. The sources were extracted with an optimal extraction with typical lengths along the slit of 6 GLYPH<149> 00 6. The sources were typically unobscured AGN, due to the relatively low resolution (FWHM GLYPH<24> 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 GLYPH<0> 1 ) grism and the red (400 lines mm GLYPH<0> 1 grating, with the D560 dichroic. The majority of observations were done with a 1 00 slit with a handful done with a 1 GLYPH<149> 00 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 00 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 ( CarPy , v. 1.4.2). The wavelength coverage was GLYPH<24> 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 GLYPH<149> 08) for velocity dispersion measurements.', '3.2.7. SDSS and Archival Data': 'Wealso 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 00 fiber at GLYPH<24> 3800-9200 Å coverage or 2 00 fiber from BOSS or eBOSS with GLYPH<24> 3600-10200 Å coverage, respectively.  \nWe 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).  \nFinally, 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 00 -radius aperture at the WISE position, except for NGC 6240N and NGC6240S, for which we use an 1 00 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 Γ bands at GLYPH<24> 7590 GLYPH<159> 𝜆 GLYPH<157> Å GLYPH<159> 7720, GLYPH<24> 6860 GLYPH<159> 𝜆 GLYPH<157> Å GLYPH<159> 6950, and GLYPH<24> 6280 GLYPH<159> 𝜆 GLYPH<157> GLYPH<159> 6340, respectively) as well as water vapor bands ( GLYPH<24> 8100 GLYPH<159> 𝜆 GLYPH<157> Å GLYPH<159> 8300, GLYPH<24> 8930 GLYPH<159> 𝜆 GLYPH<157> Å GLYPH<159> 9800). The performance has been described already in detail in Kausch et al. (2015) and Smette et al. (2015) for ESO instruments.  \nIn 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 GLYPH<24> 6800 GLYPH<159> 𝜆 GLYPH<157> Å GLYPH<159> 6900, O2 at GLYPH<24> 7460 GLYPH<159> 𝜆 GLYPH<157> Å GLYPH<159> 7560, telluric regions at GLYPH<24> 9100 GLYPH<159> 𝜆 GLYPH<157> Å GLYPH<159> 9200, and telluric regions at GLYPH<24> 9400 GLYPH<159> 𝜆 GLYPH<157> Å GLYPH<159> 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).  \nTelluric 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', '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.  \nFor 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.  \nIn 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.  \nThe 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.  \nAn 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 GLYPH<24> 10000). For spectra obtained at higher resolutions ( 𝑅 ¡ 3000) based on sky lines, we use the PHOENIX theoretical spectral library (Husser et al. 2013) as a template which has much higher resolutions ( 𝑅 GLYPH<24> 500 GLYPH<150> 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.  \nWe 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 ( GLYPH<24> 20%) than those of sky lines. For instance, for the largest sample observed using the 1.5 00 slit with Palomar/Doublespec, the average of stars observed on different nights is 4 GLYPH<149> 7 GLYPH<6> 0 GLYPH<149> 3 Å in the CaT, compared to the average of the telluric absorption with molecfit which is 4 GLYPH<149> 9 GLYPH<6> 0 GLYPH<149> 6 Å. The average from fitting sky lines for these observations is 5.8 GLYPH<6> 0.3 Å. In this case, we use use the molecfit average, though it is statistically similar  \nFigure 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 𝛼 as well as the prominent narrow emission lines at He /i.pc/i.pc 𝜆 8237 and [S /i.pc/i.pc] 𝜆 9531 emission lines. molecfit recovers these emission lines as shown with the TAC spectra, which are particularly important for accurately measuring H 𝛼 , He /i.pc/i.pc 𝜆 8237, and [S /i.pc/i.pc] 𝜆 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 /i.pc/i.pc triplet spectral region (8450-8700 Å) which is redshifted into telluric features at 𝑧¡ 0 GLYPH<149> 04 with no significant increase in residuals.  \n<!-- image -->  \nto 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 GLYPH<149> 1 GLYPH<6> 0 GLYPH<149> 2 Å vs. 4 GLYPH<149> 8 GLYPH<6> 0 GLYPH<149> 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%, j 𝑏 j ¡ 3 GLYPH<14> ). Here we describe the main survey measurements (e.g. 𝑧 , AGN type, 𝑀 BH). Further derived measurements (broad-line widths, narrow-line widths, velocity dispersions) will be provided in subsequent papers.  \nFor all the AGN in our sample, we provide the following key parameters when possible for each AGN Table 9:  \n- 1. BAT ID: Catalog ID in the BAT survey. /four.sup\n- 2. R.A. 𝛼 J2000 and decl. 𝛿 J2000: Right ascension and decl. of the optical/IR counterpart of the BAT AGN, in decimal degrees, based on WISE positions.\n- 3. DR2 Type : AGN type based on optical spectroscopy. Sy1 (with broad H 𝛽 ), Sy1.9 (narrow H 𝛽 and broad H 𝛼 ), and Sy 2 (with narrow H 𝛽 and H 𝛼 ). 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.\n- 4. 𝑧 and 𝑧 type: Best DR2 redshift measurement and the line or method used for the measurement. The majority of fits are done with [O /i.pc/i.pc/i.pc] 𝜆 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 𝛽 . For narrow-line sources, the redshift is based on emission-line fitting of [O /i.pc/i.pc/i.pc] 𝜆 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 𝛼 , SIII for [S /i.pc/i.pc] 𝜆 9531, and HeI for He /i.pc/i.pc 𝜆 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 /i.pc/v.pc 𝜆 1549 and Mg /i.pc/i.pc 𝜆 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.\n- 5. Dist and z ind: Distance assumed based on redshift or redshift independent distance measurements in Mpc.\n- 6. Best MBH and MBH 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 𝜎 ★ based BH mass estimates of order 0.5 dex (Ricci et al. 2022).\n- 7. 𝐿 bol and 𝐿 GLYPH<157> 𝐿 Edd: Measurement of the AGN bolometric luminosity and Eddington ratio based on BH mass.', '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).  \nOverall 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 𝛽 or any other broad line such as H 𝛼 ).  \nWe 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 𝛽 (Sy1), sources with narrow H 𝛽 , but broad H 𝛼 (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.  \nOverall, 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 /i.pc/i.pc/i.pc] 𝜆 5007 line emission as the primary measurement. For broad line sources (e.g. Sy1 and BZQ), the [O /i.pc/i.pc/i.pc] 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 /i.pc/i.pc/i.pc] 𝜆 5007 line is redshifted out of the spectrum, the Mg /i.pc/i.pc 𝜆 2798 (0 GLYPH<149> 8 GLYPH<159> 𝑧 GLYPH<159> 2 GLYPH<149> 6) or C /i.pc/v.pc 𝜆 1549 (2 GLYPH<149> 1 GLYPH<159> 𝑧 GLYPH<159> 3 GLYPH<149> 6) line is used.  \nK/o.pc/s.pc/s.pc /e.pc/t.pc /a.pc/l.pc.  \nTable 9. General AGN Properties  \nN/o.pc/t.pc/e.pc-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.  \nFor the Sy1.9 and Sy2 AGN, or any broad-line AGN where the fitting failed, we fit the [O /i.pc/i.pc/i.pc] 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 /i.pc/i.pc/i.pc] emission line using a single Gaussian. Finally, for 10 sources that are highly reddened and often in the Galactic plane where an [O /i.pc/i.pc/i.pc] line was not detected we use the H 𝛼 or [S /i.pc/i.pc] 𝜆 6717 GLYPH<150> 6731 or He /i.pc/i.pc 𝜆 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.  \nThere are 30 beamed AGN that are strongly continuum-dominated blazars (BZB), with only weak stellar features, and hostgalaxy-dominated blazars (BZG), where no [O /i.pc/i.pc/i.pc] 𝜆 5007 emission lines are measured. For 25 of these sources, we can measure redshifts using pPXF with the Ca H+K lines or Ca /i.pc/i.pc 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).  \nWeused 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 /i.pc/i.pc/i.pc] 𝜆 5007 line.  \nFor 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 GLYPH<149> 047 (Fortin et al. 2018) based on He /i.pc/i.pc 𝜆 10830 line. The beamed and lensed AGN PKS 1830-21, was measured using H 𝛼 in the NIR at 𝑧 = 2 GLYPH<149> 507 (Lidman et al. 1999) due to it's high extinction ( 𝐴 𝑉 ) from being in the Galactic plane.  \nOverall 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.  \n<!-- image -->  \n<!-- image -->  \n<!-- image -->  \nFigure 7. Examples of 47 sources with newly identified redshifts.  \n<!-- image -->", '4.3. Distance and Luminosity': 'The AGN host galaxies span a large range of redshifts down to very nearby ( GLYPH<159> 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.  \nWe 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 GLYPH<159> 50 Mpc (or 3500 km s GLYPH<0> 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 kms GLYPH<0> 1 in our survey.', '4.4. Black Hole Mass, Bolometric Luminosity, and Eddington Ratios': 'Wealso 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.  \nSome 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:  \n- 1. Literature measurements with megamasers, reverberation mapping, or stellar and gas dynamics.\n- 2. Broad-line H 𝛽 if 𝑁 H GLYPH<159> 10 22 cm GLYPH<0> 2 from Mejía-Restrepo et al. (2022). The conversion of broad-line measurements to BH masses is given by Trakhtenbrot & Netzer (2012).', '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:', '6. ACKNOWLEDGMENT': "We thank the reviewer for the constructive comments that helped us improve the quality of this paper.  \nBASS/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.  \nWeacknowledge 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 (311223/20206), 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.  \nWealsoacknowledgethefollowingpeople 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.  \nWe 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:  \n- (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.A0062, 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.B0959(A), 0106.A-0521(A), 385.B-1035(A), 2100.B-5018(B), and 60.A-9100(J).\n- (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).\n- (3) Observations obtained at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Ministério da Ciência, Tecnologia e Inovaç GLYPH<24> 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).\n- (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.\n- (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).\n- (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.  \n(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. SDSSacknowledges 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  \nObservatory, 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.  \nThis 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.  \nAsignificant 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.", '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 Table 16 compared to the DR1. Example spectra for the various classes (e.g., BZB, BZG, BZQ) are found in Figure 9.', '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 ( 𝑧GLYPH<159> 0 GLYPH<149> 3) the agreement is excellent, with no differences larger than 1000 km s GLYPH<0> 1 . At higher redshifts (0 GLYPH<149> 3 ¡𝑧¡ 1) the median offset increases ( j 𝑧 𝐷𝑅 2 GLYPH<0> 𝑧 𝐷𝑅 1 j = 157 kms GLYPH<0> 1 ), and finally increases to 1180 km s GLYPH<0> 1 at 𝑧¡ 1 owing to the use of the intrinsically broad lines of Mg /i.pc/i.pc 𝜆 2798 and C /i.pc/v.pc 𝜆 1549 for the derivation of the redshift.  \nK/o.pc/s.pc/s.pc /e.pc/t.pc /a.pc/l.pc.  \nTable 16. Beamed AGN Changes in DR2  \nN/o.pc/t.pc/e.pc-Column descriptions are the same as in Table 1, unless otherwise noted.  \nReferences -A19: Angioni et al. (2019); B16: Bassani et al. (2016); P19: Paliya et al. (2019); T78: Tzanetakis et al. (1978).  \n<!-- image -->  \n<!-- image -->  \nFigure 9. Figure showing the spectral classification of beamed sources based on the presence of broad lines (BZQ, top), traditional continuumdominated blazars with no emission lines or host galaxy features (BZB, middle), or only host galaxy features lacking broad lines (BZG, bottom).  \n<!-- image -->', '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. /five.sup  \n/five.sup https://www.bass-survey.com/  \nFigure 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.  \n<!-- image -->  \nFacilities: 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)  \nSoftware: 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)', 'REFERENCES': "Ahumada, R., Allende Prieto, C., Almeida, A., et al. 2020, ApJS,  \n249, 3, doi: 10.3847/1538-4365/ab929e  \nAliu, E., Archambault, S., Arlen, T., et al. 2012, ApJ, 759, 102,  \ndoi: 10.1088/0004-637X/759/2/102  \nFigure 11. 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