The GFCAT: a catalog of ultraviolet variables observed by GALEX with sub-minute resolution

TL;DR

This paper introduces GFCAT, a catalog of 1426 ultraviolet variable sources observed by GALEX at sub-minute resolution, revealing many previously unknown variables and providing detailed flare and variability data.

Contribution

The paper presents the first systematic search for short-timescale UV variability in GALEX data and introduces an enhanced analysis software, gPhoton2, enabling new time-domain studies.

Findings

Catalog includes 1426 UV variable sources, many newly identified.

Provides detailed measurements of UV flares and variability statistics.

Enables follow-up research with publicly available gPhoton2 software.

Abstract

We have performed the first systematic search of the full GALEX data archive for astrophysical variability on timescales of seconds to minutes by rebinning data across the whole mission to 30-second time resolution. The result is the GALEX Flare Catalog (GFCAT) which describes 1426 ultraviolet variable sources, including stellar flares, eclipsing binaries, $\delta$ Scuti and RR Lyrae variables, and Active Galactic Nuclei (AGN). Many of these sources have never previously been identified as variable. We have also assembled a table of observations of ultraviolet flares and accompanying statistics and measurements, including energies, and of candidate eclipsing stars. This effort was enabled by a significantly-enhanced version of the gPhoton software for analyzing time-domain GALEX data; this gPhoton2 package is available to support follow-on efforts.