Overkemping, Ann-Kristin2015-04-292015-04-292015http://hdl.handle.net/2003/3407310.17877/DE290R-7507Markarian (Mrk) 421 is a blazar, an Active Galactic Nucleus (AGN) with its jets aligned to our linof- sight. It is therefore possible to detect very high energetic γ-rays, which are produced by ultrarelativitic moving particles inside the jets. In this work this high energetic γ-radiation recorded by the MAGIC-I Cherenkov telescope on the Canary Island of La Palma is analysed. The short-term and long-term variability is examined as well as the spectral shape. Additionally, a periodicity search is performed for the resulting light curve. Finally, the MAGIC-I result is compared to lthe results of instruments measuring in other energy bands to draw conclusions on the acceleration mechanisms inside Mrk 421.enGammaastronomieMAGIC-TeleskopeAktiver Galaxienkern Mrk 421Multiwellenanalyse530Messages from a Black Holea long term analysis of the Active Galactic Nucleus Markarian 421 in the light of γ-rays measured by MAGIC-Idoctoral thesisGammaastronomieMAGIC-TeleskopAktiver galaktischer Kern