The Baryonic Tully-Fisher Relation II: Stellar Mass Models

Abstract

We present new color-${{\rm Y}}_{\ast }$ (mass-to-light) models to convert WISE W1 fluxes into stellar masses. We outline a range of possible star formation histories and chemical evolution scenarios to explore the confidence limits of stellar population models on the value of ${{\rm Y}}_{\ast }$. We conclude that the greatest uncertainties (around 0.1 dex in ${{\rm Y}}_{\ast }$) occur for the bluest galaxies with the strongest variation in recent star formation. For high mass galaxies, the greatest uncertainty arises from the proper treatment of bulge/disk separation in which to apply different ${{\rm Y}}_{\ast }$ relations appropriate for those differing underlying stellar populations. We compare our deduced stellar masses with those deduced from {\it Spitzer} 3.6$\mu$m fluxes and stellar mass estimates in the literature using optical photometry and different ${{\rm Y}}_{\ast }$ modeling. We find the correspondence to be excellent, arguing that rest-frame near-IR photometry is still more advantageous than other wavelengths.

arXiv comment20 pages, 7 figures, 2 tables, accepted by AJ