Harvesting energy driven by Comisso-Asenjo process from Kerr-MOG black holes

Abstract

Magnetic reconnection is a process that plays a critical role inplasma astrophysics by converting magnetic energy into plasmaparticle energy. Recently, Comisso and Asenjo demonstrated thatrapid magnetic reconnection within a black hole's ergosphere canefficiently extract energy from a rotating black hole. In thispaper, by considering a Kerr black hole in the MOdified gravity(MOG) framework, we investigate the impact of the MOG parameter α on the rotational energy extraction via theComisso-Asenjo process (CAP). To model energy extraction from supermassive black holes located in the center of galaxies, we set the value of α within the range inferred from the recent observation of Sgr A* by the Event Horizon Telescope (EHT). Ourresults indicate that the Kerr-MOG black hole is a more efficienthost for CAP-based rotational energy extraction compared to theKerr black hole, since it amplifies the power of energy extractionand efficiency of the plasma energization process. We show that,from the energy extraction viewpoint, the CAP is more efficientthan the Blandford-Znajek process (BZP). The latter is anothermagnetic field-based energy extraction model which is widelybelieved to be an engine for powering the high-energyastrophysics jets emerging from the supermassive black holes atactive galactic nuclei. In particular, we show that the ratio ofthe energy extraction power of CAP to BZP in the presence of theMOG parameter is greater than that of the Kerr black hole. Ourresults promise this phenomenological message that theMOG-induced correction on the Kerr black hole background plays animportant role in favor of energy extraction via the CAP.