| Name: Pankaj Kushwaha |
| Affiliation: Indian Institute of Science Education and Research (IISER) Mohali |
| Conference ID: ASI2026_497 |
| Title: X-ray Polarization and Neutrinos: Insights into Blazar's Leptonic vs Hadronic and Single vs Multizone debate |
| Abstract Type: Invited |
| Abstract Category: High Energy Phenomena, Fundamental Physics and Astronomy |
| Author(s) and Co-Author(s) with Affiliation: Pankaj Kushwaha(Indian Institute of Science Education and research (IISER) Mohali, Mohali -- 140306, India) |
| Abstract: Blazars – the active galactic nuclei with a jet directed almost towards the Earth, emit across the entire electromagnetic spectrum from radio up to GeV-TeV gamma-rays that exhibit a characteristic broad bi-modal spectral energy distribution. The radio to optical/UV and even X-rays in some, is universally accepted as the synchrotron emission. However, the origin of gamma-rays remains one of the enigmas, with leptonic (electrons) scheme attributing it to inverse Compton while Hadronic (protons) scheme attributes it to proton synchrotron or proton-photon cascades. The extensive SED investigation in the Fermi observatory era, aided by its coordinated multi-wavelength support program complemented with simultaneous variability largely implies single emission region origin favoring leptonic scheme. The claim of association of neutrinos implies presence of a subdominant hadrons contribution. The recently launched Imaging X-ray Polarimetry Explorer (IXPE), however, has revealed systematically larger X-ray polarization compared to optical (synchrotron part). In this talk, I will revisit and discuss new insights from X-ray polarization and neutrinos and their implications on the emission schemes and single vs multi-zone origin debate. |
