Circularisation in stellar tidal disruption event by supermassive black holes

• 作 者: JINYISHANGGUAN;
• 出 处: 国际天文学联合会第312次专题会议
• 发表日期: 2014年期

　　Tidal disruption events(TDEs)of stars by supermassive black holes(SMBHs)can be used to probe the dormant SMBHs in distant galaxies.The long-term light curves of TDEs satisfy the well-known t-5/3 power law very well.However,recent discoveries of TDEs with early epoch light curves show different properties,which might due to the circularisation process of the stellar debris and the very early epoch of accretion.Our work calculates the general relativistic orbits crossing of the debris to investigate the debris kinetic energy dissipation into thermal energy.Since the tidal radii of normal star are several to tens Schwarzschild radius,the orbits of debris cross each other due to general relativistic precession.The crossing of debris stream generates strong shocks that dissipate the kinetic energy of the debris into thermal energy and circularise the stream.The power of energy dissipation could reach 1042 erg/s.If only a portion of the energy radiates in soft X-ray,it could becomes visible precursors of TDEs.