Photometric stellar masses for galaxies in DESI Legacy Imaging Surveys
Year: 2025
Type: article
Abstract: In many areas of extragalactic astrophysics, we need to convert the luminosity of a galaxy into its stellar mass. In this work, we aim to find a simple and effective formula to estimate the stellar mass from the images of galaxies delivered by the currently popular DESI Legacy Imaging Surveys. This survey provides an unsurpassed combination of deep imaging and extensive sky coverage in up to four photometric bands. We calibrated the desired formula using a sample of local galaxies observed in the Spitzer Survey of Stellar Structure in Galaxies (S 4 G), which was specifically dedicated to measuring stellar masses. For the absolute magnitudes, M g and M r , of a galaxy in the g and r bands of the Legacy Surveys, we can estimate the stellar masses as 0.673 M g − 1.108 M r + 0.996 with a scatter of 25%. Employing more complex functions does not improve the estimate appreciably, even after including the galaxy ellipticity, Sérsic index, or the magnitudes in different Legacy surveys bands. Generally, measurements in the r band were the most helpful, while adding z -band measurements did not improve the mass estimate much. We provide a Python-based script, photomass_ls.py , to automatically download images of any galaxy from the Legacy surveys database, create image masks, generate GALFIT input files with well-assessed initial values, perform GALFIT photometry, and calculate stellar mass estimates. Additionally, we tuned another version of the formula to the magnitudes provided by the Siena Galaxy Atlas 2020 (SGA-2020) with a scatter of 29%. For both our default and SGA-2020 formula, we offer two alternatives derived from different calibrations of S 4 G masses based on different methods and assumptions.
Source: Astronomy and Astrophysics
Authors: Ivana Ebrová, Michal Bílek, Jiří Eliášek
Institutions: FZU - Institute of Physics of the Czech Academy of Sciences, Centre National de la Recherche Scientifique, Collège de France, Université Paris Sciences et Lettres, Observatoire de Paris, Sorbonne Université, Laboratoire d’Etudes du Rayonnement et de la Matière en Astrophysique et Atmosphères, Astronomical Observatory
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,865
Funders: National Science Foundation, U.S. Department of Energy, National Aeronautics and Space Administration, University of Pennsylvania, Ohio State University, California Institute of Technology, University of Chicago, University of Portsmouth, National Energy Research Scientific Computing Center, University College London, European Commission, University of Sussex, Deutsche Forschungsgemeinschaft, Chinese Academy of Sciences, Financiadora de Estudos e Projetos, University of Illinois at Urbana-Champaign, Office of Science, Jet Propulsion Laboratory, HORIZON EUROPE Framework Programme, Science and Technology Facilities Council, Division of Astronomical Sciences, High Energy Physics, Integrated Electronics Engineering Center, Binghamton University, Argonne National Laboratory, Fermilab, Lawrence Berkeley National Laboratory, SLAC National Accelerator Laboratory, HORIZON EUROPE Marie Sklodowska-Curie Actions
Awards: G1039895795, IMPROVING COSMOLOGICAL PRECISION BY MITIGATING DESI REDSHIFT SURVEY SYSTEMATICS, G1313983767, G1800429324, G1813527838, RUI: Stellar Mass Content of Galaxy Dark Matter Halos, G272672434, G3204085874, G387521742, G4392917094, G498139845, Galaxy mergers in the era of large surveys, G5826275554, IMPROVING COSMOLOGICAL PRECISION BY MITIGATING DESI REDSHIFT SURVEY SYSTEMATICS, G6876926712, Management and Operations of the National Optical Astronomy Observatory, G7406122311, G7861570460, G823181903, G8292014801, G969889393, G988696487, G994286665
OpenAlex ID: W4414927452