TY - JOUR
T1 - BASS. XXV. DR2 Broad-line-based Black Hole Mass Estimates and Biases from Obscuration
AU - Mejía-Restrepo, Julian E.
AU - Trakhtenbrot, Benny
AU - Koss, Michael J.
AU - Oh, Kyuseok
AU - Den Brok, Jakob
AU - Stern, Daniel
AU - Powell, Meredith C.
AU - Ricci, Federica
AU - Caglar, Turgay
AU - Ricci, Claudio
AU - Bauer, Franz E.
AU - Treister, Ezequiel
AU - Harrison, Fiona A.
AU - Urry, C. M.
AU - Ananna, Tonima Tasnim
AU - Asmus, Daniel
AU - Assef, Roberto J.
AU - Bär, Rudolf E.
AU - Bessiere, Patricia S.
AU - Burtscher, Leonard
AU - Ichikawa, Kohei
AU - Kakkad, Darshan
AU - Kamraj, Nikita
AU - Mushotzky, Richard
AU - Privon, George C.
AU - Rojas, Alejandra F.
AU - Sani, Eleonora
AU - Schawinski, Kevin
AU - Veilleux, Sylvain
N1 - Publisher Copyright:
© 2022. The Author(s). Published by the American Astronomical Society.
PY - 2022/7/1
Y1 - 2022/7/1
N2 - We present measurements of broad emission lines and virial estimates of supermassive black hole masses (M BH) for a large sample of ultrahard X-ray-selected active galactic nuclei (AGNs) as part of the second data release of the BAT AGN Spectroscopic Survey (BASS/DR2). Our catalog includes M BH estimates for a total of 689 AGNs, determined from the Hα, Hβ, Mg ii λ2798, and/or C iv λ1549 broad emission lines. The core sample includes a total of 512 AGNs drawn from the 70 month Swift/BAT all-sky catalog. We also provide measurements for 177 additional AGNs that are drawn from deeper Swift/BAT survey data. We study the links between M BH estimates and line-of-sight obscuration measured from X-ray spectral analysis. We find that broad Hα emission lines in obscured AGNs ( log(NH/cm-2)>22.0 ) are on average a factor of 8.0-2.4+4.1 weaker relative to ultrahard X-ray emission and about 35-12+7 % narrower than those in unobscured sources (i.e., log(NH/cm-2)<21.5 ). This indicates that the innermost part of the broad-line region is preferentially absorbed. Consequently, current single-epoch M BH prescriptions result in severely underestimated (>1 dex) masses for Type 1.9 sources (AGNs with broad Hα but no broad Hβ) and/or sources with log(NH/cm-2)≳22.0 . We provide simple multiplicative corrections for the observed luminosity and width of the broad Hα component (L[bHα] and FWHM[bHα]) in such sources to account for this effect and to (partially) remedy M BH estimates for Type 1.9 objects. As a key ingredient of BASS/DR2, our work provides the community with the data needed to further study powerful AGNs in the low-redshift universe.
AB - We present measurements of broad emission lines and virial estimates of supermassive black hole masses (M BH) for a large sample of ultrahard X-ray-selected active galactic nuclei (AGNs) as part of the second data release of the BAT AGN Spectroscopic Survey (BASS/DR2). Our catalog includes M BH estimates for a total of 689 AGNs, determined from the Hα, Hβ, Mg ii λ2798, and/or C iv λ1549 broad emission lines. The core sample includes a total of 512 AGNs drawn from the 70 month Swift/BAT all-sky catalog. We also provide measurements for 177 additional AGNs that are drawn from deeper Swift/BAT survey data. We study the links between M BH estimates and line-of-sight obscuration measured from X-ray spectral analysis. We find that broad Hα emission lines in obscured AGNs ( log(NH/cm-2)>22.0 ) are on average a factor of 8.0-2.4+4.1 weaker relative to ultrahard X-ray emission and about 35-12+7 % narrower than those in unobscured sources (i.e., log(NH/cm-2)<21.5 ). This indicates that the innermost part of the broad-line region is preferentially absorbed. Consequently, current single-epoch M BH prescriptions result in severely underestimated (>1 dex) masses for Type 1.9 sources (AGNs with broad Hα but no broad Hβ) and/or sources with log(NH/cm-2)≳22.0 . We provide simple multiplicative corrections for the observed luminosity and width of the broad Hα component (L[bHα] and FWHM[bHα]) in such sources to account for this effect and to (partially) remedy M BH estimates for Type 1.9 objects. As a key ingredient of BASS/DR2, our work provides the community with the data needed to further study powerful AGNs in the low-redshift universe.
UR - http://www.scopus.com/inward/record.url?scp=85134896151&partnerID=8YFLogxK
U2 - 10.3847/1538-4365/ac6602
DO - 10.3847/1538-4365/ac6602
M3 - ???researchoutput.researchoutputtypes.contributiontojournal.article???
AN - SCOPUS:85134896151
SN - 0067-0049
VL - 261
JO - Astrophysical Journal, Supplement Series
JF - Astrophysical Journal, Supplement Series
IS - 1
M1 - 5
ER -