Presentation #106.12 in the session “AGN (Poster)”.
Active galactic nuclei (AGNs) harbor intense environments that are ripe for efficient particle acceleration; however, whether they accelerate cosmic rays and produce neutrinos remains a long-standing mystery. Recently, multimessenger observations in gamma rays and neutrinos culminated in the 2017 joint detection of a flare from blazar TXS 0506+056. Additionally, the IceCube Observatory has reported observations of neutrino excesses associated with TXS 0506+056 (occurring within a 5-month period in 2014-2015) and with the radio-quiet AGN NGC 1068. While still tentative (≲ 3 sigma), these observations have provided the strongest evidence to date of a possible connection between AGNs and neutrinos. Further confirmation of this connection will require more joint observations with gamma rays, for which the medium-energy band is the best indicator as the radiation fields required for efficient neutrino production make the source opaque to higher-energy gamma rays. The All-sky Medium Energy Gamma-ray Observatory eXplorer (AMEGO-X) is a Compton-pair telescope that will feature unprecedented sensitivity in the medium-energy gamma-ray band (100 keV — >1 GeV), excellent localization capability, and groundbreaking polarization sensitivity between 100 keV and 1 MeV. AMEGO-X observations of AGNs will be crucial to probing their multimessenger nature.