A z=0 Multi-wavelength Galaxy Synthesis I: A WISE and GALEX Atlas of Local Galaxies

TL;DR

This paper introduces a comprehensive atlas of ultraviolet and infrared images for approximately 15,750 local galaxies, enabling uniform analysis of star formation rates and stellar masses, and providing a valuable resource for galaxy evolution studies.

Contribution

It presents the first large, uniform multi-wavelength atlas of local galaxies with matched resolution and astrometry, along with calibrated estimators for star formation rates and stellar masses.

Findings

Atlas includes images and catalogs for ~15,750 galaxies.

Calibrated SFR and M* estimators with high precision.

Results show a main sequence of star-forming galaxies consistent with previous studies.

Abstract

We present an atlas of ultraviolet and infrared images of ~15,750 local (d < 50 Mpc) galaxies, as observed by NASA's WISE and GALEX missions. These maps have matched resolution (FWHM 7.5'' and 15''), matched astrometry, and a common procedure for background removal. We demonstrate that they agree well with resolved intensity measurements and integrated photometry from previous surveys. This atlas represents the first part of a program (the z=0 Multi-wavelength Galaxy Synthesis) to create a large, uniform database of resolved measurements of gas and dust in nearby galaxies. The images and associated catalogs are publicly available at the NASA/IPAC Infrared Science Archive. This atlas allows us estimate local and integrated star formation rates (SFRs) and stellar masses (M$_\star$) across the local galaxy population in a uniform way. In the appendix, we use the population synthesis fits of Salim et al. (2016, 2018) to calibrate integrated M$_\star$ and SFR estimators based on GALEX and WISE. Because they leverage an SDSS-base training set of >100,000 galaxies, these calibrations have high precision and allow us to rigorously compare local galaxies to Sloan Digital Sky Survey results. We provide these SFR and M$_\star$ estimates for all galaxies in our sample and show that our results yield a "main sequence" of star forming galaxies comparable to previous work. We also show the distribution of intensities from resolved galaxies in NUV-to-WISE1 vs. WISE1-to-WISE3 space, which captures much of the key physics accessed by these bands.