CFHT UM2019 - Presentation Details

Abstract Details

Title: Structural properties of dwarf galaxies in the MATLAS low density fields

Presenter: Melina Poulain


The MATLAS survey, aimed at studying the outer most regions and surroundings of a complete sample of nearby field early type galaxies, has produced deep multi-band optical images with limiting surface brightness down to nearly 29 mag/arcsec^2 in the g band. Such images obtained with MegaCam on the CFHT have optimal conditions (large scale of view, high sensitivity) for dwarf galaxies detection. We have made a systematic survey of the dwarf galaxy satellites located within 150 fields of one square degree each. Based on semi-automatic detection algorithms, the MATLAS dwarf catalog consists of 2210 dwarf galaxies situated in low density environments. Distances have been determined for 13.5% of our sample and confirm the dwarf nature of our candidates, as well as their association with the host galaxy. Assuming for all the dwarfs a distance corresponding to that of their host, we derive their basic properties - color, mass, Sersic index, effective radius, nucleation, morphology - and their variation with environment. We find in these low density fields a majority of dwarf ellipticals, and a significant fraction of nucleated ones, as well as ultra diffuse galaxies.