| Title | Probing the Structure and Evolution of BASS Active Galactic Nuclei through Eddington Ratios |
| Authors | Ananna, Tonima Tasnim Urry, C. Megan Ricci, Claudio Natarajan, Priyamvada Hickox, Ryan C. Trakhtenbrot, Benny Treister, Ezequiel Weigel, Anna K. Ueda, Yoshihiro Koss, Michael J. Bauer, F. E. Temple, Matthew J. Balokovic, Mislav Mushotzky, Richard Auge, Connor Sanders, David B. Kakkad, Darshan Sartori, Lia F. Marchesi, Stefano Harrison, Fiona Stern, Daniel Oh, Kyuseok Caglar, Turgay Powell, Meredith C. Podjed, Stephanie A. Mejia-Restrepo, Julian E. |
| Affiliation | Dartmouth Coll, Dept Phys & Astron, 6127 Wilder Lab, Hanover, NH 03755 USA Yale Univ, Dept Phys, POB 208120, New Haven, CT 06520 USA Yale Univ, Yale Ctr Astron & Astrophys, POB 208120, New Haven, CT 06520 USA Univ Diego Portales, Fac Ingn, Nucl Astron, Av Ejercito Libertador 441, Santiago 22, Chile Peking Univ, Kavli Inst Astron & Astrophys, Beijing 100871, Peoples R China Yale Univ, Dept Astron, 52 Hillhouse Ave, New Haven, CT 06520 USA Yale Univ, Dept Phys, POB 208121, New Haven, CT 06520 USA Harvard Univ, Black Hole Initiat, 20 Garden St, Cambridge, MA 02138 USA Tel Aviv Univ, Sch Phys & Astron, IL-69978 Tel Aviv, Israel Pontificia Univ Catolica Chile, Fac Fis, Inst Astrofis, Campus San Joaquin,Av Vicuna Mackenna 4860, Macul Santiago 7820436, Chile Modulos AG, Technopk Str 1, CH-8005 Zurich, Switzerland Kyoto Univ, Dept Astron, Sakyo Ku, Kitashirakawa Oiwake Cho, Kyoto 6068502, Japan Eureka Sci, 2452 Delmer St Suite 100, Oakland, CA 94602 USA Space Sci Inst, 4750 Walnut St,Suite 205, Boulder, CO 80301 USA Pontificia Univ Catolica Chile, Fac Fis, Ctr Astroingn, Campus San Joaquin,Av Vicuna Mackenna 4860, Macul Santiago 7820436, Chile Millennium Inst Astrophys, Nuncio Monsenor Sotero Sanz 100,104, Santiago, Chile Univ Maryland, Dept Astron, College Pk, MD 20742 USA Univ Hawaii, Inst Astron, 2680 Woodlawn Dr, Honolulu, HI 96822 USA Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA Swiss Fed Inst Technol, Inst Particle Phys & Astrophys, Wolfgang Pauli Str 27, CH-8093 Zurich, Switzerland INAF Osservatorio Astrofis & Sci Spazio Bologna, Via Piero Gobetti 93-3, I-40129 Bologna, Italy Clemson Univ, Dept Phys & Astron, Kinard Lab Phys, Clemson, SC 29634 USA CALTECH, Cahill Ctr Astron & Astrophys, Pasadena, CA 91125 USA CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 169-224, Pasadena, MS 91109 USA Korea Astron & Space Sci Inst, 776 Daedeokdae Ro, Daejeon 34055, South Korea Leiden Observ, POB 9513, NL-2300 RA Leiden, Netherlands Stanford Univ, Kavli Inst Particle Astrophys & Cosmol, 452 Lomita Mall, Stanford, CA 94305 USA European Southern Observ, Casilla 19001, Santiago 19, Chile |
| Keywords | DIGITAL SKY SURVEY X-RAY LUMINOSITY FUNCTION RADIATIVE FEEDBACK BLACK-HOLES GALAXIES QUASAR POPULATION GROWTH AGN |
| Issue Date | 1-Nov-2022 |
| Publisher | ASTROPHYSICAL JOURNAL LETTERS |
| Abstract | We constrain the intrinsic Eddington ratio (lambda(Edd)) distribution function for local active galactic nuclei (AGN) in bins of low and high obscuration [log(N-H/cm(-2)) <= 22 and 22 < log(N-H/cm(-2)) < 25], using the Swift Burst Alert Telescope 70 month/BASS DR2 survey. We interpret the fraction of obscured AGN in terms of circumnuclear geometry and temporal evolution. Specifically, at low Eddington ratios (log lambda(Edd) < -2), obscured AGN outnumber unobscured ones by a factor of similar to 4, reflecting the covering factor of the circumnuclear material (0.8, or a torus opening angle of similar to 34 degrees). At high Eddington ratios (log lambda(Edd) > - 1), the trend is reversed, with <30% of AGN having log(N-H/cm(-2)) > 22, which we suggest is mainly due to the small fraction of time spent in a highly obscured state. Considering the Eddington ratio distribution function of narrow-line and broad-line AGN from our prior work, we see a qualitatively similar picture. To disentangle temporal and geometric effects at high lambda(Edd), we explore plausible clearing scenarios such that the time-weighted covering factors agree with the observed population ratio. We find that the low fraction of obscured AGN at high lambda(Edd) is primarily due to the fact that the covering factor drops very rapidly, with more than half the time spent with <10% covering factor. We also find that nearly all obscured AGN at high-lambda(Edd )exhibit some broad lines. We suggest that this is because the height of the depleted torus falls below the height of the broad-line region, making the latter visible from all lines of sight. |
| URI | http://hdl.handle.net/20.500.11897/657980 |
| ISSN | 2041-8205 |
| DOI | 10.3847/2041-8213/ac9979 |
| Indexed | SCI(E) |
| Appears in Collections: | 科维理天文与天体物理研究所 |
