c 2012. Astronomical Society of Japan. Spatial and Temporal Variations of the Diffuse Iron 6.4 keV Line in the Galactic Center Region

We analyzed the diffuse Fe I K ˛ line generated in the diffuse interstellar molecular hydrogen by primary photons or subrelativistic protons injected by Sagittarius (Sgr) A. We showed that unlike emission from compact molecular clouds, this emission can be permanently observed in the directions of the Galactic center. We conclude that the diffuse emission of the 6.4 keV line observed at present is probably due to Fe I K ˛ vacancy production by primary photons if the X-ray luminosity of Sgr A was about LX 1039–1040 erg s1. In principle these data can also be described in the framework of the model when the 6.4 keV line emission is generated by subrelativistic protons generated by accretion onto the central black hole, but in this case extreme parameters of this model are necessary