Shadows in the Dark: Low-surface-brightness Galaxies Discovered in the Dark Energy Survey

Tanoglidis, D.; Drlica-Wagner, A.; Wei, K.; Li, T. S.; Sanchez, J.; Zhang, Y.; Peter, A. H. G.; Feldmeier-Krause, A.; Prat, J.; Casey, K.; Palmese, A.; Sanchez, C.; DeRose, J.; Conselice, C.; Gagnon, L.; Abbott, T. M. C.; Aguena, M.; Allam, S.; Avila, S.; Bechtol, K.; Bertin, E.; Bhargava, S.; Brooks, D.; Burke, D. L.; Rosell, A. Carnero; Kind, M. Carrasco; Carretero, J.; Chang, C.; Costanzi, M.; da Costa, L. N.; De Vicente, J.; Desai, S.; Diehl, H. T.; Doel, P.; Eifler, T. F.; Everett, S.; Evrard, A. E.; Flaugher, B.; Frieman, J.; Garcia-Bellido, J.; Gerdes, D. W.; Gruendl, R. A.; Gschwend, J.; Gutierrez, G.; Hartley, W. G.; Hollowood, D. L.; Huterer, D.; James, D. J.; Krause, E.; Kuehn, K.; Kuropatkin, N.; Maia, M. A. G.; March, M.; Marshall, J. L.; Menanteau, F.; Miquel, R.; Ogando, R. L. C.; Paz-Chinchon, F.; Romer, A. K.; Roodman, A.; Sanchez, E.; Scarpine, V.; Serrano, S.; Sevilla-Noarbe, I.; Smith, M.; Suchyta, E.; Tarle, G.; Thomas, D.; Tucker, D. L.; Walker, A. R.; DES Collaboration
2021
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
DOI
10.3847/1538-4365/abca89
We present a catalog of 23,790 extended low-surface-brightness galaxies (LSBGs) identified in similar to 5000 deg(2) from the first three years of imaging data from the Dark Energy Survey (DES). Based on a single-component Sersic model fit, we define extended LSBGs as galaxies with g-band effective radii R-eff (g) > 2.'' 5 and mean surface brightness (mu) over bar (eff)(g) > 24.2 mag arcsec(-2). We find that the distribution of LSBGs is strongly bimodal in (g-r) versus (g-i) color space. We divide our sample into red (g-i >= 0.60) and blue (g-i<0.60) galaxies and study the properties of the two populations. Redder LSBGs are more clustered than their blue counterparts and are correlated with the distribution of nearby (z<0.10) bright galaxies. Red LSBGs constitute similar to 33% of our LSBG sample, and similar to 30% of these are located within 1 degrees of low-redshift galaxy groups and clusters (compared to similar to 8% of the blue LSBGs). For nine of the most prominent galaxy groups and clusters, we calculate the physical properties of associated LSBGs assuming a redshift derived from the host system. In these systems, we identify 41 objects that can be classified as ultradiffuse galaxies, defined as LSBGs with projected physical effective radii R-eff > 1.5 kpc and central surface brightness mu(0) g > 24.0 mag arcsec(-2). The wide-area sample of LSBGs in DES can be used to test the role of environment on models of LSBG formation and evolution.