Evidence for emission in the MeV band from $GRO J1837+59$ and $QSO 1739+522$ Available to Purchase

Emission in the MeV band from the region containing the bright unidentified EGRET source $GRO J1837+59$ and the steep-spectrum EGRET blazar $QSO 1739+522$ was first reported by COMPTEL following an observation in November 1992. During this observation the emission was consistent with a single point source, designated $GRO J1753+57.$ However, the location of $GRO J1753+57$ was not consistent with either $GRO J1837+59$ or $QSO 1739+522$ and identifying its counterpart in other wavelengths proved difficult. Moreover, subsequent observations suggested that the source could not in fact be described as a single point source and explanations involving extended or multiple sources were invoked. We present an analysis of recent observations of this region, which confirm that the emission cannot arise from a single source, but can be modelled as a combination of emission from both $GRO J1837+59$ and $QSO 1739+522.$ The spectrum and time variability derived for these two sources are discussed and compared to observations in neighboring bands.