DD.7.04 — Particle Acceleration and the origin of Very High Energy emission around black holes

Date & Time

Aug 10th at 3:00 PM until 3:15 PM




Rating ( votes)

Author(s): Elisabete de Gouveia Dal Pino1, Luis Henrique Sinki Kadowaki1, Behrouz Khiali1, Chandra Bahadur Singh1

Institution(s): 1. IAG - University of Sao Paulo

The current detectors of gamma-ray emission have too poor resolution to determine whether this emission is produced in the jet or in the core of low luminous AGNs (LLAGNs, particularly, radio galaxies) and microquasars. We have computed the power released by events of turbulent fast magnetic reconnection between the magnetic lines arising from the accretion disk and those of the black hole (BH) magnetosphere triggered by enhanced accretion, and found that this power is more than sufficient to reproduce the observed (core) radio and the gamma-ray luminosities in LLAGNs and microquasars. Moreover, this calculated power has a dependence with the BH mass of the sources that matches very well with the observed correlation between the luminosity and mass of these sources sustained for over 10 orders of magnitude in mass and power (using a sample with more than 200 sources). This match suggests a core origin for the VHE emission in these sources. Besides, based on 3D MHD simulations with test particles we demonstrated that a first-order Fermi particle acceleration within the reconnection site results in acceleration rates (proportional to $E^{-0,4}$) which are very efficient in the surrounds of the BHs. Employing this acceleration model driven by turbulent fast magnetic reconnection events in the core region, we computed the spectral energy distribution (SED) of several radio galaxies (M87, CenA, PerA, IC310 ) and microquasars (Cyg X1, Cyg X3) and found that these also match very well with the observations, therefore strengthening the conclusions above in favor of a core emission for the VHE of these sources.