XMMSL1 J074008.2-853927: A tidal disruption event with thermal and non-thermal components
Author
dc.contributor.author
Saxton, R. D.
Author
dc.contributor.author
Read, A. M.
Author
dc.contributor.author
Komossa, S.
Author
dc.contributor.author
Lira Teillery, Paulina
Author
dc.contributor.author
Alexander, K. D.
Author
dc.contributor.author
Wieringa, M. H.
Admission date
dc.date.accessioned
2019-05-29T13:10:12Z
Available date
dc.date.available
2019-05-29T13:10:12Z
Publication date
dc.date.issued
2017
Cita de ítem
dc.identifier.citation
Astronomy and Astrophysics, 598, A29 (2017)
Identifier
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14320746
Identifier
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00046361
Identifier
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10.1051/0004-6361/201629015
Identifier
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https://repositorio.uchile.cl/handle/2250/168777
Abstract
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Aims. We study X-ray bright tidal disruption events (TDE), close to the peak of their emission, with the intention of understanding the evolution of their light curves and spectra. Methods. CandidateTDEareidentifiedbysearchingforsoftX-rayflaresfromnon-activegalaxiesinrecentXMM-Newtonslewdata. Results. In April 2014, X-ray emission was detected from the galaxy XMMSL1 J074008.2-853927 (a.k.a. 2MASX 074007858539307), a factor 20 times higher than an upper limit from 20 years earlier. Both the X-ray and UV flux subsequently fell, by factorsof70and12respectively.Thebolometricluminositypeakedat Lbol ∼2×1044 ergss−1 withaspectrumthatmaybemodelled with thermal emission in the UV band, a power-law with Γ ∼ 2 dominating in the X-ray band above 2 keV and a soft X-ray excess with an effective temperature of ∼86 eV. Rapid variability locates the X-ray emission to within <73 Rg of the nuclear black hole. Radio emission of flux density∼1 mJy, peaking at 1.5 GHz was detected 21 months after discovery. Optical spectra indicate that the galaxy, at a distance of 73 Mpc (z = 0.0173), underwent a starburst 2 Gyr ago and is now quiescent. We consider a tidal disruption event to be the most likely cause of the flare. If this proves to be correct then this is a very clean example of a disruption exhibiting both thermal and non-thermal radiation.