Transient X-ray Binaries in Elliptical Galaxies

摘要: Chandra observations of elliptical galaxies have revealed large numbers Low Mass X-ray Binaries (LMXBs) accreting at rates above 10^-9 solar masses per year. One scenario which generates this transfer rate from an old stellar population is nuclear driven mass onto a neutron star or black hole Roche lobe filling red giant. However, in our Galaxy, most these systems accrete sporadically as transients due to thermal instability the accretion disk. Using common criterion for disk (including irradiation), we find that mode leads transient least 75% binary's life. Repeated should reveal population. The recurrence times might exceed 1000 years (depending on orbital period onset transfer), and outbursts last 1-100 years. transfering binaries can also be formed populations via interactions dense environments, such globular clusters. These tend shorter periods are more likely stable accretors, making them apparently fraction elliptical's LMXB