Infrared Fabry‐Perot Imaging of M82 [Fe ii ] Emission. II. Tracing Extragalactic Supernova Remnants

Abstract

We report high spatial and spectral resolution [Fe II] 1.644 μm Fabry-Perot imaging observations of M82. We present extinction-corrected [Fe II] images and discuss the nature of compact [Fe II] emission regions revealed by these new data. We conclude that these [Fe II] sources trace a population of supernova remnants in M82 that are substantially older than those revealed previously on 6 cm radiographs. In addition, we find that M82 contains a distributed [Fe II] emission component that is extended along the southern minor axis and that accounts for 90% of the galaxy's [Fe II] luminosity. We interpret this extended emission as tracing disk material entrained in a super wind that has broken out of the galactic disk to the south. We find that the [Fe II]/Brγ line ratio throughout M82 correlates with the age of the starburst as reflected by the color of the photospheric emission from the galaxy's stars. This correlation suggests that the [Fe II] emission regions in M82 are colocated with a post-main-sequence stellar population. The engineering details of our Fabry-Perot imaging methodology are also discussed.