A catalog to unite them all: REGALADE, a revised galaxy compilation for the advanced detector era

TL;DR

REGALADE is a comprehensive, high-quality all-sky galaxy catalog extending to 2000 Mpc, designed to enhance transient and multi-messenger astrophysics by providing reliable distances, stellar masses, and galaxy extents.

Contribution

It combines multiple surveys and advanced classification to produce one of the most complete and reliable galaxy catalogs for the nearby Universe, with improved data quality and coverage.

Findings

Includes nearly 80 million galaxies within 2000 Mpc.

Achieves over 90% completeness for galaxies contributing 50% of r-band luminosity out to 360 Mpc.

Recovers 60% more known supernova hosts and doubles low-luminosity transient hosts.

Abstract

Many applications in transient science, gravitational wave follow-up, and galaxy population studies require all-sky galaxy catalogs with reliable distances, extents, and stellar masses. However, existing catalogs often lack completeness beyond $\sim 100$ Mpc, suffer from stellar contamination, or do not provide homogeneous stellar mass estimates and size information. Our goal is to build a high-purity, high-completeness, all-sky galaxy catalog out to 2,000 Mpc, specifically designed to support time-domain and multi-messenger astrophysics. We combined major galaxy catalogs and deep imaging surveys -- including the Legacy Surveys, Pan-STARRS, DELVE, and SDSS -- and added spectroscopic, photometric, and redshift-independent distances. We cleaned the sample using the Gaia catalog to remove stars and visually inspected all ambiguous cases below 100 Mpc through a classification platform that gathered 27,000 expert votes. Stellar masses were estimated using optical and mid-infrared profile-fit photometry, and we improved the accuracy of photometric distances by combining multiple independent estimates. The resulting catalog, REGALADE, includes nearly 80 million galaxies with distances under 2,000 Mpc. It provides stellar masses for 88% of the sample and ellipse fits for 80%. REGALADE is more than 90% complete for galaxies contributing 50% of the total $r$-band luminosity out to 360 Mpc. In science tests, it recovers 60% more known supernova hosts, doubles the number of low-luminosity transient hosts, and identifies more reliable hosts for ultraluminous and hyper-luminous X-ray sources. REGALADE is one of the most complete and reliable all-sky galaxy catalog to date for the nearby Universe, built for real-world applications in transient and multi-messenger astrophysics. The full dataset, visual classifications, and code will be released to support broad community use.