Hard fast X-ray transients as possible counterparts of unidentified MeV/TeV sources

Abstract

The two still unidentified MeV sources EGR J1122-5946 and AGL J2022+3622 are here tentatively associated with soft gamma-ray candidate counterparts detected through INTEGRAL/IBIS observations. On the basis of spatial proximity and/or similar transient behaviour, we propose the supergiant fast X-ray transient (SFXT) IGR J11215-5952 and the candidate SFXT IGR J20188+3647 as possible candidate counterparts of EGR J1122-5946 and AGL J2022+3622, respectively. Our findings possibly suggest that hard fast X-ray transients could represent a new class of galactic transient MeV/TeV emitters. Additional evidence for the existence of such new class is also provided by very recent AGILE and GLAST discoveries on the galactic plane of several unidentified transient MeV sources lasting only a few days.

Contributed talk to appear in the proceedings of the "7th INTEGRAL Workshop - An INTEGRAL View of Compact Objects", held in Copenhagen on 8-11 September 2008