Journal-club Postdoc |
| « Tidal stripping of binary stars by massive black holes » |
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Alessandro Lupi |
| Supermassive black holes (SMBHs) are ubiquitous in the centre of massive galaxies. Most of the time they are in a quiescent state, but sometimes they can accrete matter from the surrounding and power active galactic nuclei (AGNs). Within a galactic nucleus, stellar interactions can scatter some stars on low angular momentum orbits. A tidal disruption event (TDE) could thus occur, powering a SMBH flare. For solar mass stars, these events only occur with (non-spinning) black holes (BHs) less massive than 10^8 Msun, hence they are good tracers of the quiescent BH population in a mass range complementary to that probed by surveys of bright AGNs and quasars. Because of the large fraction of stars in binary systems, also binaries can experience such a fate in pairs, immediately after being tidally separated. The consumption of both stars is expected to produce a double-peaked flare. Through hydrodynamical simulations of double TDEs, we investigate the emerging accretion luminosity and a possible subsequent evolution of the system. |
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mardi 23 février 2016 - 11:00 Salle des séminaires Évry Schatzman, Institut d'Astrophysique |
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