IceCube results from blazar stacking searches using seven years of through-going muon data

Located at the South Pole, the IceCube Neutrino Observatory is the world largest neutrino telescope. It instruments one cubic kilometre of Antarctic ice at a depth of about 1500 m to 2500 m including 5160 light detecting Digital Optical Modules. Since its construction the IceCube neutrino detector experienced remarkable success. Besides the detection of the highest energy neutrino s worldwide, IceCube is the first experiment to observe an astrophysical high-energy neutrino flux. Although in the meantime the collaboration detected more than 50 high energy neutrino events, the origin of these neutrinos is still not identified. Blazars, being a subclass of Active Galactic Nuclei and consequently one of the most powerful objects in the universe are supposed to be one of the most likely sources of high energy neutrinos. This scenario can be examined using stacking methods testing the correlation between IceCube neutrinos and the accumulation of hypothetical sources. We present here the results for three different blazar catalogs. The analyses are performed on 7 years of through-going muon data, taken by the IceCube Collaboration between 2008 and 2015.