The Astrophysical Journal (Jan 2024)
Exploring Changing-look Active Galactic Nuclei with the Sloan Digital Sky Survey V: First Year Results
- Grisha Zeltyn,
- Benny Trakhtenbrot,
- Michael Eracleous,
- Qian Yang,
- Paul Green,
- Scott F. Anderson,
- Stephanie LaMassa,
- Jessie Runnoe,
- Roberto J. Assef,
- Franz E. Bauer,
- W. N. Brandt,
- Megan C. Davis,
- Sara E. Frederick,
- Logan B. Fries,
- Matthew J. Graham,
- Norman A. Grogin,
- Muryel Guolo,
- Lorena Hernández-García,
- Anton M. Koekemoer,
- Mirko Krumpe,
- Xin Liu,
- Mary Loli Martínez-Aldama,
- Claudio Ricci,
- Donald P. Schneider,
- Yue Shen,
- Marzena Śniegowska,
- Matthew J. Temple,
- Jonathan R. Trump,
- Yongquan Xue,
- Joel R. Brownstein,
- Tom Dwelly,
- Sean Morrison,
- Dmitry Bizyaev,
- Kaike Pan,
- Juna A. Kollmeier
Affiliations
- Grisha Zeltyn
- ORCiD
- School of Physics and Astronomy, Tel Aviv University , Tel Aviv 69978, Israel ; [email protected], [email protected]
- Benny Trakhtenbrot
- ORCiD
- School of Physics and Astronomy, Tel Aviv University , Tel Aviv 69978, Israel ; [email protected], [email protected]
- Michael Eracleous
- ORCiD
- Department of Astronomy & Astrophysics, The Pennsylvania State University , University Park, PA 16802, USA; Institute for Gravitation and the Cosmos, The Pennsylvania State University , University Park, PA 16802, USA
- Qian Yang
- ORCiD
- Center for Astrophysics, Harvard & Smithsonian , 60 Garden Street, Cambridge, MA 02138, USA
- Paul Green
- ORCiD
- Center for Astrophysics, Harvard & Smithsonian , 60 Garden Street, Cambridge, MA 02138, USA
- Scott F. Anderson
- ORCiD
- Astronomy Department, University of Washington , Box 351580, Seattle, WA 98195, USA
- Stephanie LaMassa
- ORCiD
- Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA
- Jessie Runnoe
- ORCiD
- Department of Physics and Astronomy, Vanderbilt University , VU Station 1807, Nashville, TN 37235, USA
- Roberto J. Assef
- ORCiD
- Instituto de Estudios Astrofísicos, Facultad de Ingeniería y Ciencias, Universidad Diego Portales , Av. Ejército Libertador 441, Santiago, Chile
- Franz E. Bauer
- ORCiD
- Instituto de Astrofísica, Pontificia Universidad Católica de Chile , Casilla 306, Santiago 22, Chile; Millennium Institute of Astrophysics (MAS) , Nuncio Monse ñor Sótero Sanz 100, Providencia, Santiago, Chile; Space Science Institute , 4750 Walnut Street, Suite 205, Boulder, CO 80301, USA
- W. N. Brandt
- ORCiD
- Department of Astronomy & Astrophysics, The Pennsylvania State University , University Park, PA 16802, USA; Institute for Gravitation and the Cosmos, The Pennsylvania State University , University Park, PA 16802, USA; Department of Physics, 104 Davey Laboratory, The Pennsylvania State University , University Park, PA 16802, USA
- Megan C. Davis
- ORCiD
- Department of Physics, 196A Auditorium Road, Unit 3046, University of Connecticut , Storrs, CT 06269, USA
- Sara E. Frederick
- ORCiD
- Department of Physics and Astronomy, Vanderbilt University , VU Station 1807, Nashville, TN 37235, USA
- Logan B. Fries
- ORCiD
- Department of Physics, 196A Auditorium Road, Unit 3046, University of Connecticut , Storrs, CT 06269, USA
- Matthew J. Graham
- ORCiD
- California Institute of Technology , 1200 E. California Boulevard, Pasadena, CA 91125, USA
- Norman A. Grogin
- ORCiD
- Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA
- Muryel Guolo
- ORCiD
- Department of Physics and Astronomy, Johns Hopkins University , 3400 North Charles Street, Baltimore, MD 21218, USA
- Lorena Hernández-García
- ORCiD
- Millennium Institute of Astrophysics (MAS) , Nuncio Monse ñor Sótero Sanz 100, Providencia, Santiago, Chile
- Anton M. Koekemoer
- ORCiD
- Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA
- Mirko Krumpe
- Leibniz-Institut für Astrophysik Potsdam (AIP) , An der Sternwarte 16, 14482 Potsdam, Germany
- Xin Liu
- ORCiD
- Department of Astronomy, University of Illinois at Urbana-Champaign , Urbana, IL 61801, USA; National Center for Supercomputing Applications, University of Illinois at Urbana-Champaign , Urbana, IL 61801, USA; Center for Artificial Intelligence Innovation, University of Illinois at Urbana-Champaign , 1205 West Clark Street, Urbana, IL 61801, USA
- Mary Loli Martínez-Aldama
- ORCiD
- Astronomy Department, Universidad de Concepción , Casilla 160-C, Concepción 4030000, Chile
- Claudio Ricci
- ORCiD
- Instituto de Estudios Astrofísicos, Facultad de Ingeniería y Ciencias, Universidad Diego Portales , Av. Ejército Libertador 441, Santiago, Chile; Kavli Institute for Astronomy and Astrophysics, Peking University , Beijing 100871, People’s Republic of China
- Donald P. Schneider
- ORCiD
- Department of Astronomy & Astrophysics, The Pennsylvania State University , University Park, PA 16802, USA; Institute for Gravitation and the Cosmos, The Pennsylvania State University , University Park, PA 16802, USA
- Yue Shen
- ORCiD
- Department of Astronomy, University of Illinois at Urbana-Champaign , Urbana, IL 61801, USA; National Center for Supercomputing Applications, University of Illinois at Urbana-Champaign , Urbana, IL 61801, USA
- Marzena Śniegowska
- ORCiD
- School of Physics and Astronomy, Tel Aviv University , Tel Aviv 69978, Israel ; [email protected], [email protected]
- Matthew J. Temple
- ORCiD
- Instituto de Estudios Astrofísicos, Facultad de Ingeniería y Ciencias, Universidad Diego Portales , Av. Ejército Libertador 441, Santiago, Chile
- Jonathan R. Trump
- ORCiD
- Department of Physics, 196A Auditorium Road, Unit 3046, University of Connecticut , Storrs, CT 06269, USA
- Yongquan Xue
- ORCiD
- CAS Key Laboratory for Research in Galaxies and Cosmology, Department of Astronomy, University of Science and Technology of China , Hefei 230026, People’s Republic of China
- Joel R. Brownstein
- ORCiD
- Department of Physics and Astronomy, University of Utah , 115 S. 1400 East, Salt Lake City, UT 84112, USA
- Tom Dwelly
- ORCiD
- Max-Planck-Institut für extraterrestrische Physik , Giessenbachstraße, D-85748 Garching, Germany
- Sean Morrison
- ORCiD
- Department of Astronomy, University of Illinois at Urbana-Champaign , Urbana, IL 61801, USA
- Dmitry Bizyaev
- ORCiD
- Apache Point Observatory and New Mexico State University , P.O. Box 59, Sunspot, NM 88349-0059, USA; Sternberg Astronomical Institute, Moscow State University , Moscow
- Kaike Pan
- ORCiD
- Apache Point Observatory and New Mexico State University , P.O. Box 59, Sunspot, NM 88349-0059, USA
- Juna A. Kollmeier
- ORCiD
- The Observatories of the Carnegie Institution for Science , 813 Santa Barbara Street, Pasadena, CA 91101, USA; Canadian Institute for Theoretical Astrophysics , 60 Saint George Street, Toronto, ON, M5S 3H8, Canada
- DOI
- https://doi.org/10.3847/1538-4357/ad2f30
- Journal volume & issue
-
Vol. 966,
no. 1
p. 85
Abstract
“Changing-look” active galactic nuclei (CL-AGNs) challenge our basic ideas about the physics of accretion flows and circumnuclear gas around supermassive black holes. Using first-year Sloan Digital Sky Survey V (SDSS-V) repeated spectroscopy of nearly 29,000 previously known active galactic nuclei (AGNs), combined with dedicated follow-up spectroscopy, and publicly available optical light curves, we have identified 116 CL-AGNs where (at least) one broad emission line has essentially (dis-)appeared, as well as 88 other extremely variable systems. Our CL-AGN sample, with 107 newly identified cases, is the largest reported to date, and includes ∼0.4% of the AGNs reobserved in first-year SDSS-V operations. Among our CL-AGNs, 67% exhibit dimming while 33% exhibit brightening. Our sample probes extreme AGN spectral variability on months to decades timescales, including some cases of recurring transitions on surprisingly short timescales (≲2 months in the rest frame). We find that CL events are preferentially found in lower-Eddington-ratio ( f _Edd ) systems: Our CL-AGNs have a f _Edd distribution that significantly differs from that of a carefully constructed, redshift- and luminosity-matched control sample (Anderson–Darling test yielding p _AD ≈ 6 × 10 ^−5 ; median f _Edd ≈ 0.025 versus 0.043). This preference for low f _Edd strengthens previous findings of higher CL-AGN incidence at lower f _Edd , found in smaller samples. Finally, we show that the broad Mg ii emission line in our CL-AGN sample tends to vary significantly less than the broad H β emission line. Our large CL-AGN sample demonstrates the advantages and challenges in using multi-epoch spectroscopy from large surveys to study extreme AGN variability and physics.
Keywords
