First tidal disruption events discovered by <i>SRG</i>/eROSITA: X-ray/optical properties and X-ray luminosity function at <i>z</i> < 0.6
-
- S Sazonov
- Space Research Institute, Russian Academy of Sciences, Profsoyuznaya ul. 84/32, Moscow 117997, Russia
-
- M Gilfanov
- Space Research Institute, Russian Academy of Sciences, Profsoyuznaya ul. 84/32, Moscow 117997, Russia
-
- P Medvedev
- Space Research Institute, Russian Academy of Sciences, Profsoyuznaya ul. 84/32, Moscow 117997, Russia
-
- Y Yao
- Cahill Center for Astrophysics, California Institute of Technology, MC 249-17, 1200 E California Boulevard, Pasadena, CA 91125, USA
-
- G Khorunzhev
- Space Research Institute, Russian Academy of Sciences, Profsoyuznaya ul. 84/32, Moscow 117997, Russia
-
- A Semena
- Space Research Institute, Russian Academy of Sciences, Profsoyuznaya ul. 84/32, Moscow 117997, Russia
-
- R Sunyaev
- Space Research Institute, Russian Academy of Sciences, Profsoyuznaya ul. 84/32, Moscow 117997, Russia
-
- R Burenin
- Space Research Institute, Russian Academy of Sciences, Profsoyuznaya ul. 84/32, Moscow 117997, Russia
-
- A Lyapin
- Space Research Institute, Russian Academy of Sciences, Profsoyuznaya ul. 84/32, Moscow 117997, Russia
-
- A Meshcheryakov
- Space Research Institute, Russian Academy of Sciences, Profsoyuznaya ul. 84/32, Moscow 117997, Russia
-
- G Uskov
- Space Research Institute, Russian Academy of Sciences, Profsoyuznaya ul. 84/32, Moscow 117997, Russia
-
- I Zaznobin
- Space Research Institute, Russian Academy of Sciences, Profsoyuznaya ul. 84/32, Moscow 117997, Russia
-
- K A Postnov
- Sternberg Astronomical Institute, Moscow M.V. Lomonosov State University, Universitetskij pr. 13, Moscow 119992, Russia
-
- A V Dodin
- Sternberg Astronomical Institute, Moscow M.V. Lomonosov State University, Universitetskij pr. 13, Moscow 119992, Russia
-
- A A Belinski
- Sternberg Astronomical Institute, Moscow M.V. Lomonosov State University, Universitetskij pr. 13, Moscow 119992, Russia
-
- A M Cherepashchuk
- Sternberg Astronomical Institute, Moscow M.V. Lomonosov State University, Universitetskij pr. 13, Moscow 119992, Russia
-
- M Eselevich
- Institute of Solar-Terrestrial Physics, Russian Academy of Sciences, Siberian Branch, Lermontov st 126a, Irkutsk 664033, Russia
-
- S N Dodonov
- Special Astrophysical Observatory, N. Arkhyz, Karachaevo-Cherkesia 369167, Russia
-
- A A Grokhovskaya
- Special Astrophysical Observatory, N. Arkhyz, Karachaevo-Cherkesia 369167, Russia
-
- S S Kotov
- Special Astrophysical Observatory, N. Arkhyz, Karachaevo-Cherkesia 369167, Russia
-
- I F Bikmaev
- Kazan Federal University, Kremlevskaya str 18, Kazan 420008, Russia
-
- R Ya Zhuchkov
- Kazan Federal University, Kremlevskaya str 18, Kazan 420008, Russia
-
- R I Gumerov
- Kazan Federal University, Kremlevskaya str 18, Kazan 420008, Russia
-
- S van Velzen
- Leiden Observatory, Leiden University, Postbus 9513, NL-2300 RA Leiden, the Netherlands
-
- S Kulkarni
- Cahill Center for Astrophysics, California Institute of Technology, MC 249-17, 1200 E California Boulevard, Pasadena, CA 91125, USA
説明
<jats:title>ABSTRACT</jats:title> <jats:p>We present the first sample of tidal disruption events (TDEs) discovered during the SRG all-sky survey. These 13 events were selected among X-ray transients detected in the 0° < l < 180° hemisphere by eROSITA during its second sky survey (2020 June 10 to December 14) and confirmed by optical follow-up observations. The most distant event occurred at z = 0.581. One TDE continued to brighten at least 6 months. The X-ray spectra are consistent with nearly critical accretion on to black holes of a few ×103 to $10^8\, \mathrm{ M}_\odot$, although supercritical accretion is possibly taking place. In two TDEs, a spectral hardening is observed 6 months after the discovery. Four TDEs showed an optical brightening apart from the X-ray outburst. The other nine TDEs demonstrate no optical activity. All 13 TDEs are optically faint, with Lg/LX < 0.3 (Lg and LX being the g band and 0.2–6 keV luminosity, respectively). We have constructed a TDE X-ray luminosity function, which can be fit by a power law with a slope of −0.6 ± 0.2, similar to the trend observed for optically selected TDEs. The total rate is estimated at (1.1 ± 0.5) × 10−5 TDEs per galaxy per year, an order of magnitude lower than inferred from optical studies. This suggests that X-ray bright events constitute a minority of TDEs, consistent with models predicting that X-rays can only be observed from directions close to the axis of a thick accretion disc formed from the stellar debris. Our TDE detection threshold can be lowered by a factor of ∼2, which should allow a detection of ∼700 TDEs by the end of the SRG survey.</jats:p>
収録刊行物
-
- Monthly Notices of the Royal Astronomical Society
-
Monthly Notices of the Royal Astronomical Society 508 (3), 3820-3847, 2021-10-05
Oxford University Press (OUP)