X-ray burst sources near the galactic center and their burst peak luminosities

Abstract

X-ray bursts from the GCX bursters, GX 3 + 1, Terzan 1, Terzan 5, and MXB 1728-34, all within 0.1 rad from the galactic center, were observed with the Hakucho burst monitor system. Distinctly high concentration of burst sources to the galactic center direction and the frequent association of burst sources with globular clusters imply that the burst sources are located spatially near the galactic center. For probable source distances of about 10 kpc, the burst peak luminosities for these sources are found to exceed the Eddington limit for a neutron star of approximately 1.4 solar mass by large factors.