The Astrophysical Journal (Jan 2024)
Subrelativistic Outflow and Hours-timescale Large-amplitude X-Ray Dips during Super-Eddington Accretion onto a Low-mass Massive Black Hole in the Tidal Disruption Event AT2022lri
- Yuhan Yao,
- Muryel Guolo,
- Francesco Tombesi,
- Ruancun Li,
- Suvi Gezari,
- Javier A. García,
- Lixin Dai,
- Ryan Chornock,
- Wenbin Lu,
- S. R. Kulkarni,
- Keith C. Gendreau,
- Dheeraj R. Pasham,
- S. Bradley Cenko,
- Erin Kara,
- Raffaella Margutti,
- Yukta Ajay,
- Thomas Wevers,
- Tom M. Kwan,
- Igor Andreoni,
- Joshua S. Bloom,
- Andrew J. Drake,
- Matthew J. Graham,
- Erica Hammerstein,
- Russ R. Laher,
- Natalie LeBaron,
- Ashish A. Mahabal,
- Brendan O’Connor,
- Josiah Purdum,
- Vikram Ravi,
- Huei Sears,
- Yashvi Sharma,
- Roger Smith,
- Jesper Sollerman,
- Jean J. Somalwar,
- Avery Wold
Affiliations
- Yuhan Yao
- ORCiD
- Miller Institute for Basic Research in Science , 468 Donner Lab, Berkeley, CA 94720, USA ; [email protected]; Department of Astronomy, University of California , Berkeley, CA 94720, USA
- Muryel Guolo
- ORCiD
- Department of Physics and Astronomy, Johns Hopkins University , 3400 N. Charles Street, Baltimore, MD 21218, USA
- Francesco Tombesi
- ORCiD
- Physics Department, Tor Vergata University of Rome , Via della Ricerca Scientifica 1, 00133 Rome, Italy; INAF—Astronomical Observatory of Rome , Via Frascati 33, 00040 Monte Porzio Catone, Italy; INFN—Rome Tor Vergata , Via della Ricerca Scientifica 1, 00133 Rome, Italy
- Ruancun Li
- ORCiD
- Kavli Institute for Astronomy & Astrophysics and Department of Astronomy, Peking University , Beijing 100871, People's Republic of China; Department of Astronomy, School of Physics, Peking University , Beijing 100871, People's Republic of China
- Suvi Gezari
- ORCiD
- Department of Physics and Astronomy, Johns Hopkins University , 3400 N. Charles Street, Baltimore, MD 21218, USA; Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA
- Javier A. García
- ORCiD
- Astrophysics Science Division, NASA Goddard Space Flight Center , Greenbelt, MD 20771, USA
- Lixin Dai
- ORCiD
- Department of Physics, University of Hong Kong , Pokfulam Road, Hong Kong
- Ryan Chornock
- ORCiD
- Department of Astronomy, University of California , Berkeley, CA 94720, USA
- Wenbin Lu
- ORCiD
- Department of Astronomy, University of California , Berkeley, CA 94720, USA; Theoretical Astrophysics Center, University of California , Berkeley, CA 94720, USA
- S. R. Kulkarni
- ORCiD
- Cahill Center for Astrophysics, California Institute of Technology , MC 249-17, 1200 E California Boulevard, Pasadena, CA 91125, USA
- Keith C. Gendreau
- ORCiD
- Astrophysics Science Division, NASA Goddard Space Flight Center , Greenbelt, MD 20771, USA
- Dheeraj R. Pasham
- ORCiD
- Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology , Cambridge, MA 02139, USA
- S. Bradley Cenko
- ORCiD
- Astrophysics Science Division, NASA Goddard Space Flight Center , Greenbelt, MD 20771, USA; Joint Space-Science Institute, University of Maryland , College Park, MD 20742, USA
- Erin Kara
- ORCiD
- Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology , Cambridge, MA 02139, USA; Department of Physics, Massachusetts Institute of Technology , Cambridge, MA 02139, USA
- Raffaella Margutti
- ORCiD
- Department of Astronomy, University of California , Berkeley, CA 94720, USA; Department of Physics, University of California , 366 Physics North MC 7300, Berkeley, CA 94720, USA
- Yukta Ajay
- ORCiD
- Department of Physics and Astronomy, Johns Hopkins University , 3400 N. Charles Street, Baltimore, MD 21218, USA
- Thomas Wevers
- ORCiD
- Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA
- Tom M. Kwan
- ORCiD
- Department of Physics, University of Hong Kong , Pokfulam Road, Hong Kong
- Igor Andreoni
- ORCiD
- Astrophysics Science Division, NASA Goddard Space Flight Center , Greenbelt, MD 20771, USA; Joint Space-Science Institute, University of Maryland , College Park, MD 20742, USA; Department of Astronomy, University of Maryland , College Park, MD 20742, USA
- Joshua S. Bloom
- ORCiD
- Department of Astronomy, University of California , Berkeley, CA 94720, USA; Lawrence Berkeley National Laboratory , 1 Cyclotron Road, MS 50B-4206, Berkeley, CA 94720, USA
- Andrew J. Drake
- ORCiD
- Cahill Center for Astrophysics, California Institute of Technology , MC 249-17, 1200 E California Boulevard, Pasadena, CA 91125, USA
- Matthew J. Graham
- ORCiD
- Cahill Center for Astrophysics, California Institute of Technology , MC 249-17, 1200 E California Boulevard, Pasadena, CA 91125, USA
- Erica Hammerstein
- ORCiD
- Department of Astronomy, University of Maryland , College Park, MD 20742, USA
- Russ R. Laher
- ORCiD
- IPAC, California Institute of Technology , 1200 E. California Boulevard, Pasadena, CA 91125, USA
- Natalie LeBaron
- ORCiD
- Department of Astronomy, University of California , Berkeley, CA 94720, USA
- Ashish A. Mahabal
- ORCiD
- Cahill Center for Astrophysics, California Institute of Technology , MC 249-17, 1200 E California Boulevard, Pasadena, CA 91125, USA; Center for Data Driven Discovery, California Institute of Technology , Pasadena, CA 91125, USA
- Brendan O’Connor
- ORCiD
- McWilliams Center for Cosmology and Astrophysics, Department of Physics, Carnegie Mellon University , Pittsburgh, PA 15213, USA
- Josiah Purdum
- ORCiD
- Caltech Optical Observatories, California Institute of Technology , Pasadena, CA 91125, USA
- Vikram Ravi
- ORCiD
- Cahill Center for Astrophysics, California Institute of Technology , MC 249-17, 1200 E California Boulevard, Pasadena, CA 91125, USA
- Huei Sears
- ORCiD
- Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA), Northwestern University , Evanston, IL 60202, USA; Department of Physics and Astronomy, Northwestern University , Evanston, IL 60208, USA
- Yashvi Sharma
- ORCiD
- Cahill Center for Astrophysics, California Institute of Technology , MC 249-17, 1200 E California Boulevard, Pasadena, CA 91125, USA
- Roger Smith
- ORCiD
- Caltech Optical Observatories, California Institute of Technology , Pasadena, CA 91125, USA
- Jesper Sollerman
- ORCiD
- The Oskar Klein Centre, Department of Astronomy, Stockholm University , AlbaNova, SE-10691, Stockholm, Sweden
- Jean J. Somalwar
- ORCiD
- Cahill Center for Astrophysics, California Institute of Technology , MC 249-17, 1200 E California Boulevard, Pasadena, CA 91125, USA
- Avery Wold
- ORCiD
- IPAC, California Institute of Technology , 1200 E. California Boulevard, Pasadena, CA 91125, USA
- DOI
- https://doi.org/10.3847/1538-4357/ad7d93
- Journal volume & issue
-
Vol. 976,
no. 1
p. 34
Abstract
We present the tidal disruption event (TDE) AT2022lri, hosted in a nearby (≈144 Mpc) quiescent galaxy with a low-mass massive black hole (10 ^4 M _⊙ < M _BH < 10 ^6 M _⊙ ). AT2022lri belongs to the TDE-H+He subtype. More than 1 Ms of X-ray data were collected with NICER, Swift, and XMM-Newton from 187 to 672 days after peak. The X-ray luminosity gradually declined from 1.5 × 10 ^44 erg s ^−1 to 1.5 × 10 ^43 erg s ^−1 and remains much above the UV and optical luminosity, consistent with a super-Eddington accretion flow viewed face-on. Sporadic strong X-ray dips atop a long-term decline are observed, with a variability timescale of ≈0.5 hr–1 days and amplitude of ≈2–8. When fitted with simple continuum models, the X-ray spectrum is dominated by a thermal disk component with inner temperature going from ∼146 to ∼86 eV. However, there are residual features that peak around 1 keV, which, in some cases, cannot be reproduced by a single broad emission line. We analyzed a subset of time-resolved spectra with two physically motivated models describing a scenario either where ionized absorbers contribute extra absorption and emission lines or where disk reflection plays an important role. Both models provide good and statistically comparable fits, show that the X-ray dips are correlated with drops in the inner disk temperature, and require the existence of subrelativistic (0.1–0.3 c ) ionized outflows. We propose that the disk temperature fluctuation stems from episodic drops of the mass accretion rate triggered by magnetic instabilities or/and wobbling of the inner accretion disk along the black hole’s spin axis.
Keywords
- Tidal disruption
- X-ray transient sources
- Supermassive black holes
- Time domain astronomy
- High energy astrophysics
- Accretion
