The Extended Disc Galaxy Exploration Science Survey: description and surface brightness profile properties

Abstract

The survey description and near-infrared properties for 92 galaxies are presented for the Extended Disc Galaxy Exploration Science (EDGES) Survey, along with an investigation into the properties of the stellar haloes of these galaxies. EDGES is a Spitzer Space Telescope Warm Mission program designed to reach the surface brightness limit (∼0.5 kJy sr$^{−1}$ or 29 AB mag arcsec$^{−2}$) of the Infrared Array Camera (IRAC) 3.6 and 4.5$μ$m bands for a wide range of galaxy types found within the local volume. The surface brightness profiles exhibit a large range in disc scale length, with breaks more frequently seen than in previous studies, owing in large part to the extremely deep near-infrared imaging. A number of these surface brightness profile breaks may be due to stellar haloes, up to seven galaxies out of the full sample of 92 galaxies, and we explore these implications in relation to current cosmological models. We also report the discovery of a new tidal stream near NGC 3953.