Relativistic jets in active galactic nuclei: studying nature’s most powerful particle accelerators in the multi-messenger era

Dr. Manel Errando, Washington University in St. Louis

Relativistic jets in active galactic nuclei (AGN) are fueled by accretion onto supermassive black holes. Decades of observations, from radio frequencies to gamma rays, have recently been extended beyond the electromagnetic spectrum to charged cosmic rays and neutrinos.  The emerging multi-messenger picture reveals that jets are capable of accelerating particles well beyond the TeV scale, making them the most powerful cosmic accelerators in the Universe.

I will discuss recent observations of relativistic jets in AGN with VERITAS, a ground-based TeV gamma-ray observatory, that include the detection of the furthest known source of TeV gamma rays and the observation of a flaring AGN in coincidence with a neutrino event detected by IceCube, a neutrino observatory located in the South Pole. I will discuss the impact of these results in our understanding of the particle acceleration and radiation mechanisms in relativistic jets and how they constrain the properties of the intergalactic medium.