2016A&A...586A...9H -
Astronomy and Astrophysics, volume 586A, 9-9 (2016/2-1)
Unbeamed tidal disruption events at hard X-rays.
HRYNIEWICZ K. and WALTER R.
Abstract (from CDS):
Owing to their thermal emission, tidal disruption events (TDEs) were regularly detected in the soft X-rays and sometimes in the optical. Only a few TDEs have been detected at hard X-rays: two are high redshift beamed events, one of which occurred at the core of a nearby galaxy, and the most recent one is of a different nature, involving a compact object in the Milky Way. The aims of this work are to obtain a first sample of hard X-ray-selected unbeamed TDEs, to determine their frequency and to probe whether TDEs usually or exceptionally emit at hard X-ray energies. We performed extensive searches for hard X-ray flares at positions in over 53000 galaxies, up to a distance of 100Mpc in the Swift/BAT archive. Light curves were extracted and parametrized. The quiescent hard X-ray emission was used to exclude persistently active galactic nuclei. Significant flares from non-active galaxies were derived and checked for possible contamination. We found a sample of nine TDE candidates, which translates into a rate of 2x10^-5/galaxy/yr above the BAT detection limit. This rate is consistent with those observed by XMM-Newton at soft X-rays and in the optical from SDSS observations, and is as expected from simulations. We conclude that hard X-ray emission should be ubiquitous in un-beamed TDEs and that electrons should be accelerated in their accretion flow.
Abstract Copyright:
∼
Journal keyword(s):
accretion, accretion disks - black hole physics - galaxies: nuclei
CDS comments:
Paragraph 4.1 Zw 022.21 not identified.
Simbad objects:
70
Full paper
View the references in ADS
To bookmark this query, right click on this link: simbad:2016A&A...586A...9H and select 'bookmark this link' or equivalent in the popup menu