Year: 2020
Type: article
Abstract: A galaxy’s stellar mass-to-light ratio ( ) is a useful tool for converting luminosity to stellar mass ( ). However, the practical utility of inferred from stellar population synthesis (SPS) models is limited by mismatches between the real and assumed models for star-formation history (SFH) and dust geometry, both of which vary within galaxies. Here, we measure spatial variations in and their dependence on color, SFH, and dust across the disk of M31, using a map of derived from color–magnitude diagrams of resolved stars in the Panchromatic Hubble Andromeda Treasury survey. First, we find comparable scatter in for the optical and mid-IR, contrary to the common idea that is less variable in the IR. Second, we confirm that is correlated with color for both the optical and mid-IR and report color versus relations (CMLRs) in M31 for filters used in the Sloan Digital Sky Survey and Widefield Infrared Survey Explorer . Third, we show that the CMLR residuals correlate with recent SFH, such that quiescent regions are offset to higher than star-forming regions at a fixed color. The mid-IR CMLR, however, is not linear due to the high scatter of in star-forming regions. Finally, we find a flatter optical CMLR than any SPS-based CMLRs in the literature. We show that this is an effect of dust geometry, which is typically neglected but should be accounted for when using optical data to map .
Source: The Astrophysical Journal
Authors: O. Grace Telford, Julianne J. Dalcanton, Benjamin F. Williams, Eric F. Bell, Andrew E. Dolphin, Meredith J. Durbin, Yumi Choi
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
Funders: National Science Foundation, U.S. Department of Energy, National Aeronautics and Space Administration, Alfred P. Sloan Foundation, Princeton University, Ohio State University, California Institute of Technology, University of Washington, Johns Hopkins University, University of Pittsburgh, Case Western Reserve University, Drexel University, Universität Basel, University of Portsmouth, New Mexico State University, Space Telescope Science Institute, Chinese Academy of Sciences, Max-Planck-Gesellschaft, Max-Planck-Institut für Astronomie, Jet Propulsion Laboratory, University of California, Los Angeles, U.S. Naval Observatory, Fermilab, Los Alamos National Laboratory
Awards: G1110571158, G145748691, G1826481930, G1968183688, Graduate Research Fellowship Program (GRFP), G2299114855, G4182629103, G4325766086, G433322167, G4518818167, IGERT-CIF21: Big Data U: A Program for Integrated Multidisciplinary Education and Research for Big Data Science, G5159282255, SI2-SSE: The Next Generation of the Montage Mosaic Engine, G58316358, G5909228286, G6273510985, G6756316859, G767601387, G8210229802, G8404944017, G8934477357
OpenAlex ID: W3001177276