Stellar tidal disruption candidates found by cross-correlating the ROSAT Bright Source Catalogue and XMM-Newton observations

Abstract

We performed a systematic search for stellar tidal disruption events (TDE) by looking for X-ray sources that were detected during the ROSAT All Sky Survey and faded by more than an order of magnitude over the next two decades according to XMM-Newton serendipitous observations. Besides a number of highly variable persistent X-ray sources (like active galactic nuclei and cataclysmic variables), we found three sources that are broadly consistent with the TDE scenario: 1RXS J114727.1+494302, 1RXS J130547.2+641252, and 1RXS J235424.5-102053. A TDE association is also acceptable for the fourth source, 1RXS J112312.7+012858, but an AGN origin cannot be ruled out either. This statistics implies a TDE rate of ∼3 × 10^-5 yr^-1 per galaxy in the Universe within z ∼ 0.18, which is broadly consistent with the estimates of the TDE rate in the more local Universe obtained previously.