We use mid-infrared variability in galaxies to search for active galactic nuclei (AGN) in the local universe. We use a sample of 10,220 galaxies from the Mapping Nearby Galaxies at APO (MaNGA) survey, part of the Sloan Digital Sky Survey (SDSS-IV). For each galaxy, we examine its mid-infrared variability in the W2[4.6μm] band over thirteen years using data from the Wide Infrared Survey Explorer (WISE) All-Sky and Near Earth Objects WISE (NEOWISE) missions. We demonstrate that we can detect variability signatures as small as about 7% in the root-mean-square variation of W2 flux for the majority of cases. Using other AGN signatures of the variable galaxies, such as optical narrow lines, optical broad lines, and WISE W1−W2 colors, we show that ∼75% of the variables show these additional AGN signatures, indicating that the bulk of these cases are likely to be AGN. We also identify seven galaxies that have light-curves characteristic of tidal disruption events. We present here a publicly available catalog of the light-curve variability in W2 of these galaxies.
@article{arxiv.2407.05508,
title = {Mid-Infrared Variability in Nearby Galaxies from the MaNGA Sample},
author = {Aashay Pai and Michael R. Blanton and John Moustakas},
journal= {arXiv preprint arXiv:2407.05508},
year = {2024}
}