Newly discovered dwarf galaxies in the MATLAS low-density fields

We present the photometric properties of 2210 newly identified dwarf galaxy candidates in the Mass Assembly of early Type gaLAxies with their fine Structures (MATLAS) fields. The MATLAS deep imaging survey mapped ∼142 deg² of the sky around nearby isolated early type galaxies using MegaCam on the Canada-France-Hawaii Telescope, reaching surface brightnesses of ∼28.5-29 in the g band. The dwarf candidates were identified through a direct visual inspection of the images and by visually cleaning a sample selected using a partially automated approach, and were morphologically classified at the time of identification. Approximately 75 per cent of our candidates are dEs, indicating that a large number of early type dwarfs also populate low-density environments, and 23.2 per cent are nucleated. Distances were determined for 13.5 per cent of our sample using pre-existing z_spec measurements and H I detections. We confirm the dwarf nature for 99 per cent of this sub-sample based on a magnitude cut M_g = -18. Additionally, most of these (∼90 per cent) have relative velocities suggesting that they form a satellite population around nearby massive galaxies rather than an isolated field sample. Assuming that the candidates over the whole survey are satellites of the nearby galaxies, we demonstrate that the MATLAS dwarfs follow the same scaling relations as dwarfs in the Local Group as well as the Virgo and Fornax clusters. We also find that the nucleated fraction increases with M_g, and evidence of a morphology-density relation for dwarfs around isolated massive galaxies.