We report the discovery of a mid-infrared variable AGN which is hosted by an ultraluminous infrared galaxy (ULIRG) candidate in the Sloan Stripe 82 field. \textit{WISE} \textit{J030654.88+010833.6} is a red, extended galaxy, which we estimate to be at a photometric redshift of 0.28 ≤ z ≤ 0.31, based on its optical and near-infrared spectral energy distribution (SED). The factor of two variability over 8 years seen in the \textit{WISE} 3.4 and 4.6 μm wavelength channels is not clearly correlated with optical variability in archival data. Based on our estimation of the physical parameters of the host galaxy, \textit{J030654.88+010833.6} is possibly a composite AGN/starburst ULIRG in a phase where high star formation ∼ 70 M⊙ year−1 is occurring. Our estimate of the black hole mass to stellar mass ratio also appears to be consistent with that of broad-line AGN in the local universe. The long-term variability of \textit{J030654.88+010833.6} as seen in the \textit{WISE} \textit{W1} and \textit{W2} light curves is likely due to variations in the accretion rate, with the energy being reprocessed by dust in the vicinity of the AGN.
@article{arxiv.1908.04280,
title = {A Flaring AGN In a ULIRG candidate in Stripe 82},
author = {Abhishek Prakash and Ranga Ram Chary and George Helou and Andreas Faisst and Matthew J. Graham and Frank J. Masci and David L. Shupe and Bomee Lee},
journal= {arXiv preprint arXiv:1908.04280},
year = {2019}
}
Comments
Accepted for publication in the Astrophysical Journal, 11 pages