Published online by Cambridge University Press: 19 July 2016
A comparison of the XMM-Newton and Chandra Galactic Center Surveys has revealed two faint X-ray transients with contrasting properties. The X-ray spectrum of XMM J174544−2913.0 shows a strong iron line with an equivalent width of ∼2 keV, whereas that of XMM J174457−2850.3 is characterized by a very hard continuum with photon index ∼1.0. The X-ray flux of both sources varied by more than two orders of magnitude over a period of months with a peak X-ray luminosity of 5 × 1034 ergs s−1. We discuss the nature of these peculiar sources.