2013/03/01 by Stacy McGaugh, McGaugh, Stacy, Jim Schombert +1
Physics and Astronomy · #Astronomy and Astrophysical Research #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena #Stellar, planetary, and galactic studies
paper · pdf · doi:10.48550/arxiv.1303.0320
openalex publication_date 2013/03/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We present new Spitzer 3.6 micron observations of a sample of disk galaxies\nspanning over 10 magnitudes in luminosity and ranging in gas fraction from ~10%\nto over 90%. We use these data to test population synthesis prescriptions for\ncomputing stellar mass. Many commonly employed models fail to provide\nself-consistent stellar masses in the sense that the stellar mass estimated\nfrom the optical luminosity typically exceeds that estimated from the\nnear-infrared (NIR) luminosity. This problem is present in models both with and\nwithout TP-AGB stars, but is more severe in the former. Self-consistency can be\nachieved if NIR mass-to-light ratios are approximately constant with a mean\nvalue near 0.5 Msun/Lsun at 3.6 microns. We use the Baryonic Tully-Fisher\nrelation calibrated by gas rich galaxies to provide an independent estimate of\nthe color-mass to light ratio relation. This approach also suggests that the\ntypical 3.6 micron mass-to-light ratio is 0.5 (0.65 in the K band) for\nrotationally supported galaxies. These values are consistent with a Kroupa IMF.\n