Identification of GRLB candidates

Gamma-ray-loud binary systems (GRLB) are X-ray binaries which emit VHE gamma rays . Only 4 such systems, have been detected as persistent or regularly variable TeV emitters. The source of the high-energy activity of these GRLBs is uncertain. For understanding the nature of GRLBs a larger number of similar objects is required. Most of the variable and transient Galactic sources of GeV gamma-rays are expected to belong to the GRLB class. We produced a variability map of GC plane at 300MeV -- 300GeV using more than 3years of FERMI data, that allowed to identify 3 variable unidentified sources, that are candidates to GRLBs. We propose the 10ksec XMM observation of each of these sources to determine the nature of these sources and to check whether these sources are GRLBs.