Emma Kun
Ruhr University Bochum, Germany
Cosmic neutrinos from radio-loud and radio quiet AGN
The production mechanism of astrophysical high-energy neutrinos is not yet understood. The first astrophysical high-energy neutrino source candidate identified by IceCube at a significance level of >3sigma was a blazar, TXS 0506+056, an accreting supermassive black hole that drives a relativistic jet directed towards Earth. Recently, IceCube also discovered strong evidence that Seyfert galaxies also emit neutrinos, which appears unrelated to jet activity. In our previous works we found that gamma-ray suppression, resulting in a dip in the gamma-ray light curve of the neutrino point sources during neutrino emission, is a necessary consequence of the neutrino production process itself. Here, we show that the neutrino--hard X-ray flux ratio of blazar TXS 0506+056 is consistent with neutrino production in a gamma-obscured region near the central supermassive black hole, with the X-ray flux corresponding to reprocessed gamma-ray emission with comparable flux to that of neutrinos. Similar neutrino--hard X-ray flux ratios were found for three of IceCube's Seyfert galaxies, raising the possibility of a common neutrino production mechanism.