Original: X-ray Spectral Analysis of a Serendipitously Observed Active Galactic Nucleus

Sammanfattning: An active galactic nucleus (AGN) is a region in the center of a galaxy with a supermassive black hole continuosly accreting material. This accretion gives rise to large amounts of radiation across the whole electromagnetic spectrum, and largely affects the regions around the AGN and the evolution of the whole galaxy. Using X-ray spectral analysis, a study is performed of a supposed AGN at position J130028.5+283010.1 (celestial coordinates) that was captured as a secondary object during observations of a galaxy cluster in front of \textit{X Comae}. Six observations by \textit{XMM-Newton} during the years 2004--2006 are used, extracted using the XMM-SAS tools and analysed using XSPEC. The analysis shows that this object most probably is an AGN, and the spectrum varies significantly between observations. Furthermore, the later observations show some difficult-to-model features, possibly hinting at the presence of emission reflected in the accretion disk around the supermassive black hole in the center of the AGN. This thesis presents a summary of the spectral properties of the AGN and its evolution over time.