Investigating the EGRET-radio galaxies link with INTEGRAL: The case of 3EG J1621+8203 and NGC 6251

Abstract

The analysis of an INTEGRAL AO2 observation of the error contours of the EGRET source 3EG J1621 + 8203 is presented. The only source found inside the error contours for energies between 20 and 30 keV at 5σ detection significance is the FR I radio galaxy NGC 6251. This supports the identification of NGC 6251 with 3EG J1621 + 8203. The observed flux is higher and softer than observed in the past, but consistent with a variable blazar-like spectral energy distribution. © ESO 2005.