MORPHOLOGIES OF ACTIVE GALACTIC NUCLEI HOST GALAXIES OBSERVED IN MID-INFRARED WAVELENGTHS

Active Galactic Nuclei (AGN) are structures found in some galaxies where the central supermassive black hole accretes material from the surrounding galaxy. Galaxy mergers are the predominant theory for what triggers black hole accretion. The hypothesis tested in this study is that AGN with distorted morphologies, indicating a recent merger, would be obscured by surrounding dust. To study this, the morphologies and colors of mid-infrared (MIR) variability-selected AGN in five extragalactic fields imaged by the Hubble Space Telescope were studied. First, it was determined which galaxies were obscured by dust by examining their optical-to-MIR color indices using photometry in the R-band and at 4.5 microns. Next, HST images of these galaxies in the Rainbow catalog were examined to determine if their morphologies indicated a recent merger. Based on these results, it was determined that the obscured galaxies were no more likely to have recently undergone a merger than unobscured galaxies.