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arXiv · 1202.5900

A tidal disruption-like X-ray flare from the quiescent galaxy SDSS J120136.02+300305.5

R. D. Saxton·A. M. Read·P. Esquej·S. Komossa·S. Dougherty·P. Rodriguez-Pascual·D. Barrado
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Abstract

SDSS J120136.02+300305.5 was detected in an XMM-Newton slew from June 2010 with a flux 56 times higher than an upper limit from ROSAT, corresponding to Lx~3x10^44 ergs/s. It has the optical spectrum of a quiescent galaxy (z=0.146). Overall the X-ray flux has evolved consistently with the canonical t^-5/3 model, expected for returning stellar debris from a tidal disruption event, fading by a factor ~300 over 300 days. In detail the source is very variable and became invisible to Swift between 27 and 48 days after discovery, perhaps due to self-absorption. The X-ray spectrum is soft but is not the expected tail of optically thick thermal emission. It may be fit with a Bremsstrahlung or double-power-law model and is seen to soften with time and declining flux. Optical spectra taken 12 days and 11 months after discovery indicate a deficit of material in the broad line and coronal line regions of this galaxy, while a deep radio non-detection implies that a jet was not launched during this event.

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R. D. Saxton, A. M. Read, P. Esquej, S. Komossa, S. Dougherty, P. Rodriguez-Pascual, D. Barrado. 2012-02-27. A tidal disruption-like X-ray flare from the quiescent galaxy SDSS J120136.02+300305.5. https://doi.org/10.1051/0004-6361/201118367

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