090163

Triple AGN are signposts of ongoing galaxy mergers and are the observational progenitors of the loudest low-frequency gravitational wave (GW) events in the Universe. Thus studying the population of triple galaxy merger systems for evidence of SMBH activity is imperative to understanding the expected GW event rate detectable with pulsar timing arrays as well as which environmental dependencies are linked with AGN activity. However to date only one serendipitously discovered X-ray triple AGN has been identified. We propose to observe 8 nearby (0.018 and amp amp amp lt z and amp amp amp lt 0.051) triple galaxy mergers with XMM-Newton and measure the number of AGN in each triple merger system. These observations will expand upon results from a recent X-ray analysis of 7 triple galaxy mergers that had existing archival X-ray data. [truncated! Please see actual data for full text]