Speaker
Description
IceCube neutrinos select some of the most extreme blazars known. Population studies reveal this pattern statistically, and here I will focus on two individual blazars singled out by IceCube: TXS 0506+056 and PKS 1424+240. Together, they expose the physics behind the population-level result with high-resolution radio monitoring revealing a surprising picture. What look like slow jets are actually aimed almost straight at us, with their fastest motion hidden beneath slower structure. This geometry is long-known to explain their electromagnetic brightness. Their prominence in IceCube flux points to a deeper implication: the neutrino output is also concentrated along the jet. The neutrino-producing protons must therefore move preferentially in the jet direction. I will touch on ongoing radio follow-ups of IceCube alerts and archival searches designed to test this picture and uncover other jets with similarly extreme properties.