Speaker
Description
Magnetic fields around rotating black holes can produce diverse astrophysical phenomena. We first discuss the particle acceleration by magnetic Penrose process. Penrose process is a novel way to extract the rotational energy of the black holes, but it requires a special condition, generally not expected in typical astrophysical situations. However, magnetic Penrose process can extract the energy from the electromagnetic potential in a more generic condition. We explore the particle acceleration by the magnetic Penrose process where neutrons are produced within the hot accretion flow and then transported to the acceleration zone close to the black hole and decayed into protons which are subsequently accelerated to very high energy, especially for Sgr A*. We find a non-negligible fraction of PeV protons and TeV gamma rays observed near Earth have contribution from this process. Secondly, we explore the magnetic field configuration for the Blandford-Znajek process around Kerr black holes, incorporating the effect of force-free plasma. General relativistic Grad-Shafranov equations are solved for the combined field of split monopole and uniform vertical field with a jet-like configuration. We numerically found regular solutions suitable for the observed astrophysical jet, and the estimated electromagnetic power is consistent with that of the observed jet.
| Research Area | Relativistic Astrophysics |
|---|