Reference MATLAS ultra diffuse galaxies (Marleau+, 2021) ================================================================================ Ultra diffuse galaxies in the MATLAS low-to-moderate density fields Marleau F.R., Habas R., Poulain M., Duc. P.A., Mueller O., Lim S., Durrell P.R., Sanchez-Janssen R., Paudel S., Ahad S.L., Chougule A., Bilek M., Fensch J. =2021A&A... ... ================================================================================ ADC_Keywords: Galaxies, optical; Galaxies, photometry; Galaxy catalogs; Magnitudes; Galaxies, nearby Keywords: galaxies: dwarf - galaxies: nuclei - galaxies: photometry - galaxies: structure Abstract: Recent advances in deep dedicated imaging surveys over the past decade have uncovered a surprisingly large number of extremely faint low surface brightness galaxies with large physical sizes called ultra diffuse galaxies (UDGs) in clusters and, more recently, in lower density environments. As part of the Mass Assembly of early-Type GaLAxies with their fine Structures (MATLAS) survey, a deep imaging large program at the Canada-France-Hawaii Telescope (CFHT), our team has identified 2210 dwarf galaxies, 59 (~3%) of which qualify as UDGs. Averaging over the survey area, we find ~0.4 UDG per square degree. They are found in a range of low to moderate density environments, although 61% of the sample fall within the virial radii of groups. Based on a detailed analysis of their photometric and structural properties, we find that the MATLAS UDGs do not show significant differences from the traditional dwarfs, except from the predefined size and surface brightness cut. Their median color is as red as the one measured in galaxy clusters, albeit with a narrower color range. The majority of the UDGs are visually classified as dwarf ellipticals with log stellar masses of 6.5-8.7. The fraction of nucleated UDGs (~34%) is roughly the same as the nucleated fraction of the traditional dwarfs. Only five (~8%) UDGs show signs of tidal disruption and only two are tidal dwarf galaxy candidates. A study of globular cluster (GC) candidates selected in the CFHT images finds no evidence of a higher GC specific frequency S_N for UDGs than for classical dwarfs, contrary to what is found in most clusters. The UDG halo-to-stellar mass ratio distribution, as estimated from the GC counts, peaks at roughly the same value as for the traditional dwarfs, but spans the smaller range of ~10-2000. We interpret these results to mean that the large majority of the field-to-group UDGs do not have a different formation scenario than traditional dwarfs. Description: This work is based on data in the g, r and i-band from the MATLAS survey (Duc et al., 2015, MNRAS, 446, 120) performed with the Canada-France-Hawaii Telescope. This catalogue presents the properties of the 59 MATLAS ultra diffuse galaxies. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table1.txt 136 59 Photometric properties of the MATLAS UDGs table2.txt 145 59 Additional properties of the MATLAS UDGs Byte-by-byte Description of file: table1.txt -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 11 A11 --- ID UDG ID 15- 22 F8.4 --- RA Right ascension 26- 32 F7.4 --- Dec Declination 35- 38 A4 --- Morph Morphology 44- 52 A9 --- Distance Assumed host ETG distance, dwarf distance 59- 72 A14 --- g Apparent mangitude in the g-band 81- 93 A13 --- g-r g-r color corrected for Galactic extinction 102-114 A13 --- g-i g-i color corrected for Galactic extinction 121-135 A15 --- Mg Absolute magnitude in the g-band computed using the UDG distance when available, otherwise the assumed host ETG distance is used -------------------------------------------------------------------------------- Byte-by-byte Description of file: table2.txt -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 11 A11 --- ID UDG ID 18- 31 A14 --- mu0 Central surface brightness in the g-band 37- 50 A14 --- mueavg Average surface brightness within one effective radius in the g-band 57- 70 A14 --- Rearcsec Effective radius in arcsec in the g-band 77- 89 A13 --- Rekpc Effective radius in kpc in the g-band computed using the UDG distance when available, otherwise the assumed host distance is used 96-106 A11 --- log(Mstar/Msol) Stellar mass computed based on the stellar mass-to-light ratios from Bell et al. (2003) and the derived g-r color 119-144 A26 --- Mhalo/Mstar Halo-to-stellar mass ratio computed based on the mass ratio from Harris et al. (2017) and the derived GC count -------------------------------------------------------------------------------- ================================================================================