You are cordially invited to a colloquium by Dr Athira Bharathan.
Title: Unveiling High-Energy Emission Processes in Blazars through Variability, Neutrino Emission, and X-ray Polarization.
Abstract:
Blazars, a class of active galactic nuclei with relativistic jets aligned close to our line of sight, are among the most luminous and variable sources in the Universe. Their broad spectral energy distribution, spanning from radio to gamma rays, is shaped by complex radiative processes operating in relativistic jets. Despite decades of study, the exact mechanisms responsible for their high-energy emission, whether leptonic or hadronic in origin, remain a subject of active debate.
In this talk, I will present a multi-faceted view of blazar emission by combining three key diagnostics, spectral variability, neutrino emission, and X-ray polarization. Variability across different energy bands offers crucial insights into the dynamics of the emission region, while the detection of high-energy neutrinos provides direct evidence of hadronic interactions in blazar jets. Recently, X-ray polarization measurements from NASA’s Imaging X-ray Polarimetry Explorer (IXPE) have added a new dimension, constraining the magnetic field geometry and particle acceleration mechanisms at play.
Through selected case studies, I will discuss how these complementary observables together help decode the physical processes driving high-energy emission in blazars. This multi-messenger and polarization-based approach opens new avenues to probe jet composition, magnetic field structure, and the link between electromagnetic and neutrino emissions, shedding light on one of the most energetic phenomena in the Universe.
Join the meeting now
Meeting ID: 397 381 730 735 9
Passcode: MR77Ek2j
For more information, kindly contact Joseph Magwanya.