During a close encounter between a star and a supermassive black hole,the star can get disrupted by the black hole’s tidal forces,resulting in a tidal disruption event(TDE).The accretion of the star’s material onto ...During a close encounter between a star and a supermassive black hole,the star can get disrupted by the black hole’s tidal forces,resulting in a tidal disruption event(TDE).The accretion of the star’s material onto the black hole produces strong emission in different wavelength regimes.Here we report the discovery with the Roentgen Satellite(ROSAT)of an X-ray-selected transient source in an optically non-active galaxy.At the location R.A.:13h31m57s.66 and decl.:-32°43’19".7 a sudden rise in X-ray luminosity by a factor of 8 within 8 days has been observed.Additionally,a very soft X-ray spectrum with a blackbody temperature kT=0.1 keV and a peak luminosity of at least 1×10^(43)erg s^(-1)suggests a TDE interpretation,and the observed properties are very similar to previously identified soft X-ray(ROSAT)TDEs.An optical spectrum taken of the galaxy at the position of RXJ133157.6324319.7 six years after the X-ray outburst does not show any emission lines as would be expected from a persistent active galactic nucleus.The redshift of the galaxy is determined to be 0.051 based on absorption lines.It is therefore likely a member of the galaxy cluster A3560.The rise in X-ray luminosity happens within 8 days and thus appears to be fast for such an event.No X-ray emission was detected 170 days before and 165 days after the event,and none was detected 25 yr later with the Neil Gehrels Swift Observatory.The change in X-ray luminosity is at least a factor of 40.展开更多
基金supported by the German Bundesministerium fur Bildung,Wissenschaft,Forschung und Technologie(BMBF/DARA)the Max-Planck-Society。
文摘During a close encounter between a star and a supermassive black hole,the star can get disrupted by the black hole’s tidal forces,resulting in a tidal disruption event(TDE).The accretion of the star’s material onto the black hole produces strong emission in different wavelength regimes.Here we report the discovery with the Roentgen Satellite(ROSAT)of an X-ray-selected transient source in an optically non-active galaxy.At the location R.A.:13h31m57s.66 and decl.:-32°43’19".7 a sudden rise in X-ray luminosity by a factor of 8 within 8 days has been observed.Additionally,a very soft X-ray spectrum with a blackbody temperature kT=0.1 keV and a peak luminosity of at least 1×10^(43)erg s^(-1)suggests a TDE interpretation,and the observed properties are very similar to previously identified soft X-ray(ROSAT)TDEs.An optical spectrum taken of the galaxy at the position of RXJ133157.6324319.7 six years after the X-ray outburst does not show any emission lines as would be expected from a persistent active galactic nucleus.The redshift of the galaxy is determined to be 0.051 based on absorption lines.It is therefore likely a member of the galaxy cluster A3560.The rise in X-ray luminosity happens within 8 days and thus appears to be fast for such an event.No X-ray emission was detected 170 days before and 165 days after the event,and none was detected 25 yr later with the Neil Gehrels Swift Observatory.The change in X-ray luminosity is at least a factor of 40.
