Black Hole Jet Sheath as a Candidate for the Comptonizing Corona

          @misc{ pirsa_PIRSA:25030131,
            doi = {10.48660/25030131},
            url = {https://pirsa.org/25030131},
            author = {Sridhar, Navin},
            keywords = {Strong Gravity},
            language = {en},
            title = {Black Hole Jet Sheath as a Candidate for the Comptonizing Corona},
            publisher = {Perimeter Institute},
            year = {2025},
            month = {mar},
            note = {PIRSA:25030131 see, \url{https://pirsa.org}}
          }
          

Abstract

What powers the hard, non-thermal X-rays from accreting compact objects has been a longstanding mystery. In my talk, I will address the underlying question of what energizes the particles of the Comptonizing “corona” against the strong inverse Compton (IC) cooling losses with first-principle particle-in-cell simulations of magnetic reconnection subject to IC cooling in magnetically dominated electron-positron plasmas, and in mildly-magnetized electron-ion plasmas. I will also show---using results of global resistive GRMHD simulations of accreting black holes---that the black hole jet sheath is a site of efficient electromagnetic dissipation through processes such as magnetic reconnection and turbulence. The distribution of bulk motions of the radially outflowing plasma along the jet sheath also resembles a Maxwellian distribution with an effective bulk temperature of a few 100 keV, and this could be a candidate for the Comptonizing corona.