A New WISE Calibration of Stellar Mass

Abstract

We derive new empirical scaling relations between WISE mid-infrared galaxy photometry and well-determined stellar masses from SED modeling of a suite of optical-infrared photometry provided by the DR4 Catalogue of the GAMA-KiDS-VIKING survey of the southern G23 field. The mid-infrared source extraction and characterization are drawn from the WISE Extended Source Catalogue (WXSC) and the archival ALLWISE catalog, combining both resolved and compact galaxies in the G23 sample to a redshift of 0.15. Three scaling relations are derived: W1 3.4 micron luminosity versus stellar mass, and WISE W1-W2, W1-W3 colors versus mass-to-light ratio (sensitive to a variety of galaxy types from passive to star-forming). For each galaxy in the sample, we then derive the combined stellar mass from these scaling relations, producing Mstellar estimates with better than $\sim$25-30% accuracy for galaxies with $>$10$^{9}$ Msolar and $<$40 - 50% for lower luminosity dwarf galaxies. We also provide simple prescriptions for rest-frame corrections and estimating stellar masses using only the W1 flux and the W1-W2 color, making stellar masses more accessible to users of the WISE data. Given a redshift or distance, these new scaling relations will enable stellar mass estimates for any galaxy in the sky detected by WISE with high fidelity across a range of mass-to-light.