Circular orbits and accretion process near a regular phantom black hole

Abstract

The relativistic accretion onto astrophysical compact objects such as black holes and neutron stars is the natural phenomena for releasing energy, with up to 40% of the rest-mass energy of the matter accreting on the black hole able to be liberated. High luminosities due to accretion are observed in X-ray binaries, and in active galactic nuclei (AGN). In this paper, we investigate the geodesics motion and accretion process near a regular phantom black hole by taking an isothermal fluid with spherically symmetric black hole spacetime. The geodesic motion around the black hole during accretion provide the disc like structure. Here, we give some reasons to make circular orbits and accretion process for the considered black hole. Firstly, we discuss the motion of test particles with stabilities near the equatorial plane which make the circular orbits. Then we analyze perturbations via restoring forces and oscillations of particles around the central object. Finally, we discuss the critical speed of the fluid flow and maximum accretion rate. The physical validity of our results shows that the phantom parameter b plays an important role for the circular orbits and the maximum accretion rate.