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BASS. XXI. The Data Release 2 Overview

Koss, Michael J. and Trakhtenbrot, Benny and Ricci, Claudio and Bauer, Franz E. and Treister, Ezequiel and Mushotzky, Richard and Urry, C. Megan and Ananna, Tonima T. and Baloković, Mislav and den Brok, Jakob S. and Cenko, S. Bradley and Harrison, Fiona and Ichikawa, Kohei and Lamperti, Isabella and Lein, Amy and Mejía-Restrepo, Julian E. and Oh, Kyuseok and Pacucci, Fabio and Pfeifle, Ryan W. and Powell, Meredith C. and Privon, George C. and Ricci, Federica and Salvato, Mara and Schawinski, Kevin and Shimizu, Taro and Smith, Krista L. and Stern, Daniel (2022) BASS. XXI. The Data Release 2 Overview. Astrophysical Journal Supplement Series, 261 (1). Art. No. 1. ISSN 0067-0049. doi:10.3847/1538-4365/ac6c8f.

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The BAT AGN Spectroscopic Survey (BASS) is designed to provide a highly complete census of the key physical parameters of the supermassive black holes (SMBHs) that power local active galactic nuclei (AGNs) (z ≲ 0.3), including their bolometric luminosity (L_(bol)), black hole (BH) mass (M_(BH)), accretion rates (L_(bol)/L_(Edd)), line-of-sight gas obscuration (N_H), and the distinctive properties of their host galaxies (e.g., star formation rates, masses, and gas fractions). We present an overview of the second data release of BASS (DR2), an unprecedented spectroscopic AGN survey in spectral range, resolution, and sensitivity, including 1449 optical (∼3200 Å–1 μm) and 233 near-IR (1–2.5 μm) spectra for the brightest 858 ultrahard X-ray (14–195 keV) selected AGNs across the entire sky and essentially all levels of obscuration. This release provides a highly complete set of key measurements (emission-line measurements and central velocity dispersions), with 99.9% measured redshifts and 98% BH masses estimated (for unbeamed AGNs outside the Galactic plane). The BASS DR2 AGN sample represents a unique census of nearby powerful AGNs, spanning over 5 orders of magnitude in AGN bolometric luminosity (L_(bol) ∼ 10⁴⁰–10⁴⁷ erg s⁻¹), BH mass (M_(BH) ∼ 10⁵–10¹⁰ M_⊙), Eddington ratio (L_(bol)/L_(Edd) ≳ 10−5), and obscuration (N_H ∼ 10²⁰–10²⁵ cm⁻²). The public BASS DR2 sample and measurements can thus be used to answer fundamental questions about SMBH growth and its links to host galaxy evolution and feedback in the local universe, as well as open questions concerning SMBH physics. Here we provide a brief overview of the survey strategy, the key BASS DR2 measurements, data sets and catalogs, and scientific highlights from a series of DR2-based works pursued by the BASS team.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Koss, Michael J.0000-0002-7998-9581
Trakhtenbrot, Benny0000-0002-3683-7297
Ricci, Claudio0000-0001-5231-2645
Bauer, Franz E.0000-0002-8686-8737
Treister, Ezequiel0000-0001-7568-6412
Mushotzky, Richard0000-0002-7962-5446
Urry, C. Megan0000-0002-0745-9792
Ananna, Tonima T.0000-0001-8211-3807
Baloković, Mislav0000-0003-0476-6647
den Brok, Jakob S.0000-0002-8760-6157
Cenko, S. Bradley0000-0003-1673-970X
Harrison, Fiona0000-0003-2992-8024
Ichikawa, Kohei0000-0002-4377-903X
Lamperti, Isabella0000-0003-3336-5498
Lein, Amy0000-0002-7851-9756
Mejía-Restrepo, Julian E.0000-0001-8450-7463
Oh, Kyuseok0000-0002-5037-951X
Pacucci, Fabio0000-0001-9879-7780
Pfeifle, Ryan W.0000-0001-8640-8522
Powell, Meredith C.0000-0003-2284-8603
Privon, George C.0000-0003-3474-1125
Ricci, Federica0000-0001-5742-5980
Salvato, Mara0000-0001-7116-9303
Schawinski, Kevin0000-0001-5464-0888
Shimizu, Taro0000-0002-2125-4670
Smith, Krista L.0000-0001-5785-7038
Stern, Daniel0000-0003-2686-9241
Alternate Title:BAT AGN Spectroscopic Survey XXI: The Data Release 2 Overview
Additional Information:© 2022. The Author(s). Published by the American Astronomical Society. Received 2021 September 7; revised 2022 April 29; accepted 2022 May 4; published 2022 July 15. The BAT AGN Spectroscopic Survey Data Release 2. 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 No. 1849/19 (B.T.); the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program, through grant agreement No. 950533 (B.T.); FONDECYT Regular 1190818 (E.T., F.E.B.) and 1200495 (E.T., F.E.B); ANID grants CATA-Basal AFB-170002 (E.T., F.E.B.), ACE210002 (E.T., F.E.B.), and FB210003 (C.R., E.T., F.E.B.); ANID Anillo ACT172033 and Millennium Nucleus NCN19_058 (E.T.); Millennium Science Initiative Program—ICN12_009 (F.E.B.); an ESO fellowship (M.H., J.M.); Fondecyt Iniciacion grant 11190831 (C.R.); the National Research Foundation of Korea grant NRF-2020R1C1C1005462 and the Japan Society for the Promotion of Science ID: 17321 (K.O.); Comunidad de Madrid through the Atracción de Talento Investigador grant 2018-T1/TIC-11035 (I.L.); support from the National Science Foundation under grant No. AST-1715512 (C.M.U.); YCAA Prize Postdoctoral Fellowship (M.B.); and from a Clay Fellowship administered by the Smithsonian Astrophysical Observatory and by the Black Hole Initiative at Harvard University, which is funded by grants from the John Templeton Foundation and the Gordon and Betty Moore Foundation (F.P.). This work was performed in part at the Aspen Center for Physics, which is supported by National Science Foundation grant PHY-1607611. We acknowledge the work done by the 50+ BASS scientists and Swift BAT team 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 data obtained through the European Organisation for Astronomical Research in the Southern Hemisphere (ESO); the Palomar Observatory; the Southern Astrophysical Research (SOAR); the Kitt Peak National Observatory, managed by the US National Science Foundation's NOIRLab; the 6.5 m Magellan and the 2.5 m du Pont telescopes located at Las Campanas Observatory, Chile; the W. M. Keck Observatory at Maunakea, Hawaii; and the various stages of the Sloan Digital Sky Survey (SDSS). A full list of observing facilities, program numbers, and their supporting bodies is provided in the main DR2 Catalog paper (Koss et al. 2022a; see the acknowledgments there). A significant part of the BASS observations and work took place during the COVID-19 crisis. We thank the healthcare experts in communities around the world, for their tireless efforts to keep us all as safe and healthy as possible. Facilities: Du Pont (Boller & Chivens spectrograph) - , Keck:I (LRIS) - , Magellan:Clay - , Hale (DBSP) - , 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), Numpy (van der Walt et al. 2011), Pandas (
Group:Astronomy Department, Space Radiation Laboratory
Funding AgencyGrant Number
Israel Science Foundation1849/19
European Research Council (ERC)950533
Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT)1190818
Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT)1200495
Agencia Nacional de Investigación y Desarrollo (ANID)ACE210002
Agencia Nacional de Investigación y Desarrollo (ANID)FB210003
Agencia Nacional de Investigación y Desarrollo (ANID)ACT172033
Agencia Nacional de Investigación y Desarrollo (ANID)NCN19_058
Comisión Nacional de Investigación Científica y Tecnológica (CONICYT)ICN12_009
European Southern Observatory (ESO)UNSPECIFIED
Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT)11190831
National Research Foundation of KoreaNRF-2020R1C1C1005462
Japan Society for the Promotion of Science (JSPS)17321
Comunidad de Madrid2018-T1/TIC-11035
Yale Center for Astronomy and AstrophysicsUNSPECIFIED
Smithsonian Astrophysical ObservatoryUNSPECIFIED
Harvard UniversityUNSPECIFIED
Black Hole InitiativeUNSPECIFIED
John Templeton FoundationUNSPECIFIED
Gordon and Betty Moore FoundationUNSPECIFIED
Subject Keywords:Active galactic nuclei; AGN host galaxies; X-ray active galactic nuclei; X-ray surveys; Sky surveys; Supermassive black holes
Issue or Number:1
Classification Code:Unified Astronomy Thesaurus concepts: Active galactic nuclei (16); AGN host galaxies (2017); X-ray active galactic nuclei (2035); X-ray surveys (1824); Sky surveys (1464); Supermassive black holes (1663)
Record Number:CaltechAUTHORS:20220726-997598000
Persistent URL:
Official Citation:Michael J. Koss et al 2022 ApJS 261 1
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:115857
Deposited By: George Porter
Deposited On:27 Jul 2022 21:09
Last Modified:27 Jul 2022 21:09

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