Preprint

Sub-relativistic 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 YaoDepartment of Astronomy , University of California , Berkeley , CA 94720 , USAMuryel GuoloDepartment of Physics and Astronomy , Johns Hopkins University , 3400 N. Charles Street , Baltimore , MD 21218 , USAFrancesco TombesiRuancun LiDepartment of Astronomy , School of Physics , Peking University , Beijing 100871 , ChinaSuvi GezariDepartment of Physics and Astronomy , Johns Hopkins University , 3400 N. Charles Street , Baltimore , MD 21218 , USAJavier A. GarcíaDai, LixinDepartment of Physics , University of Hong Kong , Pokfulam Road , Hong KongR. ChornockWenbin LuTheoretical Astrophysics Center , University of California , Berkeley , CA 94720 , USAS. R. KulkarniKeith C. GendreauDheeraj R. PashamKavli Institute for Astrophysics and Space Research , Massachusetts Institute of Technology , Cambridge , MA 02139 , USAS. B. CenkoJoint Space-Science Institute , University of Maryland , College Park , MD 20742 , USAErin KaraDepartment of Physics , Massachusetts Institute of Technology , Cambridge , MA 02139 , USAR. MarguttiDepartment of Astronomy , University of California , Berkeley , CA 94720 , USAYukta AjayDepartment of Physics and Astronomy , Johns Hopkins University , 3400 N. Charles Street , Baltimore , MD 21218 , USAT. WeversSpace Telescope Science Institute , 3700 San Martin Drive , Baltimore , MD 21218 , USATom M. KwanIgor AndreoniJ. S. BloomDepartment of Astronomy , University of California , Berkeley , CA 94720 , USAA. J. DrakeCahill Center for Astrophysics , California Institute of Technology , MC 249-17 , 1200 E California Boulevard , Pasadena , CA 91125 , USAM. J. GrahamErica HammersteinDepartment of Astronomy , University of Maryland , College Park , MD 20742 , USARuss R. LaherInfrared Processing and Analysis CenterNatalie LeBaronAshish A MahabalBrendan O’ConnorMcWilliams Center for Cosmology and Astrophysics , Department of Physics , Carnegie Mellon University , Pittsburgh , PA 15213 , USAJosiah PurdumVikram RaviCahill Center for Astrophysics , California Institute of Technology , MC 249-17 , 1200 E California Boulevard , Pasadena , CA 91125 , USAHuei SearsCenter for Interdisciplinary Exploration and Research in Astrophysics (CIERA) , Northwestern University , Evanston , IL 60202 , USAY. SharmaCahill Center for Astrophysics , California Institute of Technology , MC 249-17 , 1200 E California Boulevard , Pasadena , CA 91125 , USARoger M. SmithCaltech Optical Observatories , California Institute of Technology , Pasadena , CA 91125J. SollermanAlbaNovaJean J. SomalwarCahill Center for Astrophysics , California Institute of Technology , MC 249-17 , 1200 E California Boulevard , Pasadena , CA 91125 , USAAvery WoldIPAC , California Institute of Technology , 1200 E. California Blvd , Pasadena , CA 91125 , USA

2024en

ABI

Annotatsiya

We present the tidal disruption event (TDE) AT2022lri, hosted in a nearby ($\approx\!144$ Mpc) quiescent galaxy with a low-mass massive black hole ($10^4\,M_\odot < M_{\rm BH} < 10^6\,M_\odot$). 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 d to 672 d after peak. The X-ray luminosity gradually declined from $1.5\times 10^{44}\,{\rm erg\,s^{-1}}$ to $1.5\times 10^{43}\,{\rm erg\,s^{-1}}$ 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 variability timescale of $\approx\!0.5$ hr--1 d and amplitude of $\approx\!2$--8. When fitted with simple continuum models, the X-ray spectrum is dominated by a thermal disk component with inner temperature going from $\sim\! 146$ eV to $\sim\! 86$ 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 either a scenario 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 sub-relativistic (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.

Hali tarjima qilinmagan

Identifikatorlar

DOI: 10.48550/arxiv.2405.11343

Iqtiboslar va manbalar

0 ta iqtibos0 ta foydalanilgan manba