The Stellar Masses of Disk Galaxies and the Calibration of Color-Mass to Light Ratio Relations

Understand

We present new Spitzer 3.6 micron observations of a sample of disk galaxies spanning over 10 magnitudes in luminosity and ranging in gas fraction from ~10% to over 90%.

• We use these data to test population synthesis prescriptions for computing stellar mass.
• Many commonly employed models fail to provide self-consistent stellar masses in the sense that the stellar mass estimated from the optical luminosity typically exceeds that estimated from the near-infrared (NIR) luminosity.
• This problem is present in models both with and without TP-AGB stars, but is more severe in the former.