The Baryonic Tully-Fisher Relation II: Stellar Mass Models

TL;DR

This paper develops new models to estimate stellar masses from WISE W1 fluxes, analyzing uncertainties and comparing with other methods, to improve understanding of galaxy mass relations.

Contribution

Introduces new color-$_*$ models for stellar mass estimation from WISE data, exploring uncertainties and validating against existing methods.

Findings

Uncertainties in $_*$ are around 0.1 dex for blue galaxies.

Proper bulge/disk separation is crucial for high-mass galaxy mass estimates.

Near-IR photometry provides more reliable stellar mass estimates than optical or other wavelengths.

Abstract

We present new color-$\Upsilon_*$ (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 $\Upsilon_*$. We conclude that the greatest uncertainties (around 0.1 dex in $\Upsilon_*$) 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 $\Upsilon_*$ 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 $\Upsilon_*$ modeling. We find the correspondence to be excellent, arguing that rest-frame near-IR photometry is still more advantageous than other wavelengths.