TY - JOUR

T1 - X-Ray Properties of TDEs

AU - Saxton, R.

AU - Komossa, S.

AU - Auchettl, K.

AU - Jonker, P. G.

N1 - Correction to vol.216, Issue: 1 10.1007/s11214-020-00759-7

PY - 2020/7/1

Y1 - 2020/7/1

N2 - Observational astronomy of tidal disruption events (TDEs) began with the detection of X-ray flares from quiescent galaxies during the ROSAT all-sky survey of 1990-1991. The flares complied with theoretical expectations, having high peak luminosities (Lx up to >= 4 x 10(44) erg/s), a thermal spectrum with kT similar to few x 10(5) K, and a decline on timescales of months to years, consistent with a diminishing return of stellar debris to a black hole of mass10(6-8) M-circle dot. These measurements gave solid proof that the nuclei of quiescent galaxies are habitually populated by a super-massive black hole. Beginning in 2000, XMM-Newton, Chandra andSwifthave discovered further TDEs which have been monitored closely at multiple wavelengths. A general picture has emerged of, initially near-Eddington accretion, powering outflows of highly-ionised material, giving way to a calmer sub-Eddington phase, where the flux decays monotonically, and finally a low accretion rate phase with a harder X-ray spectrum indicative of the formation of a disk corona. There are exceptions to this rule though which at the moment are not well understood. A few bright X-ray TDEs have been discovered in optical surveys but in general X-ray TDEs show little excess emission in the optical band, at least at times coincident with the X-ray flare. X-ray TDEs are powerful new probes of accretion physics down to the last stable orbit, revealing the conditions necessary for launching jets and winds. Finally we see that evidence is mounting for nuclear and non-nuclear intermediate mass black holes based on TDE flares which are relatively hot and/or fast.

AB - Observational astronomy of tidal disruption events (TDEs) began with the detection of X-ray flares from quiescent galaxies during the ROSAT all-sky survey of 1990-1991. The flares complied with theoretical expectations, having high peak luminosities (Lx up to >= 4 x 10(44) erg/s), a thermal spectrum with kT similar to few x 10(5) K, and a decline on timescales of months to years, consistent with a diminishing return of stellar debris to a black hole of mass10(6-8) M-circle dot. These measurements gave solid proof that the nuclei of quiescent galaxies are habitually populated by a super-massive black hole. Beginning in 2000, XMM-Newton, Chandra andSwifthave discovered further TDEs which have been monitored closely at multiple wavelengths. A general picture has emerged of, initially near-Eddington accretion, powering outflows of highly-ionised material, giving way to a calmer sub-Eddington phase, where the flux decays monotonically, and finally a low accretion rate phase with a harder X-ray spectrum indicative of the formation of a disk corona. There are exceptions to this rule though which at the moment are not well understood. A few bright X-ray TDEs have been discovered in optical surveys but in general X-ray TDEs show little excess emission in the optical band, at least at times coincident with the X-ray flare. X-ray TDEs are powerful new probes of accretion physics down to the last stable orbit, revealing the conditions necessary for launching jets and winds. Finally we see that evidence is mounting for nuclear and non-nuclear intermediate mass black holes based on TDE flares which are relatively hot and/or fast.

KW - X-ray

KW - TDE

KW - Black holes

KW - Accretion disks

KW - TIDAL DISRUPTION EVENT

KW - MULTIWAVELENGTH FOLLOW-UP

KW - SUPERMASSIVE BLACK-HOLES

KW - XMM-NEWTON

KW - CHANDRA OBSERVATIONS

KW - GALACTIC NUCLEI

KW - HOST GALAXIES

KW - SKY SURVEY

KW - STAR

KW - CANDIDATE

U2 - 10.1007/s11214-020-00708-4

DO - 10.1007/s11214-020-00708-4

M3 - Review

VL - 216

JO - Space Science Reviews

JF - Space Science Reviews

SN - 0038-6308

IS - 5

M1 - 85

ER -