Satyapal, ShobitaEllison, Sara L.McAlpine, WilliamHickox, Ryan C.Patton, David R.Trevor Mendel, J.2025-06-022025-06-020035-8711http://www.scopus.com/inward/record.url?scp=84900541670&partnerID=8YFLogxKhttps://hdl.handle.net/1885/733756366Interactions between galaxies are predicted to cause gas inflows that can potentially trigger nuclear activity. Since the inflowing material can obscure the central regions of interacting galaxies, a potential limitation of previous optical studies is that obscured active galactic nuclei (AGNs) can be missed at various stages along the merger sequence. We present the first large mid-infrared study of AGNs in mergers and galaxy pairs, in order to quantify the incidence of obscured AGNs triggered by interactions. The sample consists of galaxy pairs and post-mergers drawn from the Sloan Digital Sky Survey that are matched to detections by the Wide-Field Infrared Sky Explorer. We find that the fraction of AGNs in the pairs, relative to a mass-, redshift-and environment-matched control sample, increases as a function of decreasing projected separation. This enhancement is most dramatic in the post-merger sample, where we find a factor of 10-20 excess in the AGN fraction compared with the control. Although this trend is in qualitative agreement with results based on optical AGN selection, the mid-infrared-selected AGN excess increases much more dramatically in the post-mergers than is seen for an optical AGN. Our results suggest that energetically dominant optically obscured AGNs become more prevalent in the most advanced mergers, consistent with theoretical predictions.8enGalaxies: activeGalaxies: evolutionGalaxies: interactionsGalaxies: Seyfert201410.1093/mnras/stu65084900541670