ELECTRON HEATING AND ACCELERATION BY MAGNETIC RECONNECTION IN HOT ACCRETION FLOWS

Both analytical and numerical works show that magnetic reconnection must occur in hot accretion flows. This process will effectively heat and accelerate electrons. In this paper, we use the numerical hybrid simulation of magnetic reconnection plus the test-electron method to investigate the electron acceleration and heating due to magnetic reconnection in hot accretion flows. We consider fiducial values of density, temperature, and magnetic parameter beta(e) (defined as the ratio of the electron pressure to the magnetic pressure) of the accretion flow as n(0) similar to 10(6) cm(-3), T-e(0) similar to 2 x 10(9) K, and beta(e) = 1. We find that electrons are heated to a higher temperature T-e = 5 x 10(9) K, and a fraction eta similar to 8% of electrons are accelerated into a broken power-law distribution, dN(gamma) proportional to gamma(-p), with p approximate to 1.5 and 4 below and above similar to 1 MeV, respectively. We also investigate the effect of varying beta and n(0). We find that when beta(e) is smaller or n(0) is larger, i.e., the magnetic field is stronger, T-e, eta, and p all become larger.