| Abstract : | Observation of flares from very close to black holes (AGN and BH-XRBs ) indicates rich and intricate magnetohydrodynamical physics in the inner accretion region. Rapid variability in observed light curves in several wavelength bands seems to correspond to a timescale shorter than the light-crossing timescale of the event horizon. This timescale straightforwardly corresponds to a few Schwarzschild radii of the length scale of the emitting region from causality relation. Plasmoids are projected to be potential candidates to explain observations of both the energetics and short variability timescale from such regions. Plasmoids are formed in the magnetic reconnection process by forming current sheets. Magnetic reconnection in finite resistivity regime is a plausible mechanism for converting magnetic energy to thermal and kinetic energy of charged particles present in the accretion flow. In current work, a thin resistive axisymmetric accretion disk in equilibrium is set up numerically around a Kerr black hole in General Relativistic Magneto Hydro Dynamics(GRMHD) framework. We perform a GRMHD simulation of two thin disks with different resistivity values, one being moderately resistive and the other being low resistive, up to a time of t = 2000 GM/c^3. In both resistivity regimes, we study the size distribution and energetics of resulting plasmoids in the inner accretion region (tens of gravitational radii ). We discuss the implications of the formation and size distribution of the plasmoids, which are gravitationally unbound due to significant acceleration in the high magnetization region. We use the distribution of the Bernoulli parameter for detecting those plasmoids. Additionally, we discuss the energetics of the plasmoids that could account for possible subsequent flaring activities in AGNs. |
