Discovery of Extensive [O iii] Emission Near M31

Abstract

Abstract We report the discovery of a broad, 1.°5 long filamentary [O iii ] emission nebulosity some 1.°2 southeast of the M31 nucleus. This nebulosity is not detected in H α and has no obvious emission counterparts in X-ray, UV, optical, infrared, and radio surveys. To our knowledge, this emission feature has not been previously reported in the literature. We briefly discuss its possible origin.