Speaker: Dr. Aleksandr Plavin

Host: Prof. Ignacio Taboada

Title: Looking Down the Jet: Blazars, Beaming, and Neutrinos

Abstract:

IceCube neutrino detections select some of the most extreme blazars known. I'll touch on population studies that demonstrate this pattern statistically, and will focus on two individual blazars singled out by IceCube: TXS 0506+056 and PKS 1424+240. High-resolution radio monitoring of these two blazars reveals the physics behind the population-level result. What look like slow jets are actually aimed almost straight at us, with their high flow speeds masked by viewing geometry and slower-moving bright features. This orientation has long been known to explain their electromagnetic brightness. Their association with IceCube neutrinos points to a deeper implication: the neutrino output of an active galaxy is also concentrated along its jet. The neutrino-producing protons must therefore move preferentially in the jet direction. I will discuss ongoing observational and modeling efforts to test this picture, uncover other jets with similarly extreme properties, and connect observable jet properties to proton acceleration and neutrino production.