EPJ Web of Conferences
Volume 39, 2012Tidal Disruption Events and AGN Outbursts
|Number of page(s)||5|
|Section||Observations - High Energy (X, Gamma)|
|Published online||18 December 2012|
Discovery of a tidal disruption event candidate from the 2XMM catalog
1 CNRS, IRAP, 9 avenue du Colonel Roche, BP. 44346 31028 Toulouse Cedex 4, France
2 Université de Toulouse, UPS-OMP, IRAP, Toulouse, France
3 Department of Physics and Astronomy, University of Alabama, Tuscaloosa, AL 35487, USA
4 Gemini Observatory/AURA, Southern Operations Center, Casilla 603, La Serena, Chile
5 Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Lab, University Park, PA 16802, USA
6 Sydney Institute for Astronomy (SIfA), School of Physics, The University of Sydney, NSW 2006, Australia
a e-mail: email@example.com
Stars approaching a supermassive black hole (SMBH) can be tidally disrupted and subsequently accreted, providing a unique way to find and study inactive SMBHs. We report on our discovery of a new tidal disruption event candidate, 2XMMi J184725.1-631724, with unprecedented ultrasoft X-ray spectra near the flare peak. It lies toward the center of an inactive galaxy at z = 0.0353. It was detected serendipitously in two XMM-Newton observations separated by 211 days, with the flux increasing by a factor of ∼9. The source was not detected in X-rays by ROSAT in 1992, indicating a long-term variability factor of >64; neither by Swift in 2011, implying a flux decay factor of >12 since the last XMM-Newton observation. The XMM-Newton X-ray spectra are dominated by a strong cool thermal disk (>80%, tens of eV) with the luminosity appearing to follow the L ∝ T4 relation, often seen in the thermal state of the BH X-ray binaries. Both XMM-Newton observations show large variability on timescales of hours. This can be explained as due to fast variations in the mass accretion rate, maybe caused by the shocks during the tidal disruption of the star.
© Owned by the authors, published by EDP Sciences, 2012
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 2.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.