| Abstract: We investigate the effects of thermal conduction in relativistic accretion flow around rotating black holes. In doing so, we employ both hydrodynamical and magnetohydrodynamical (MHD) approaches. In this investigation, we consider the toroidal magnetic field, incorporating synchrotron and bremsstrahlung cooling processes. We self-consistently solve the steady-state fluid equations to obtain global transonic solutions for low angular momentum accretion flows in the presence of dissipation. Furthermore, we study the role of thermal conduction on the existence of shock solution and the behaviour of key shock properties including shock location, compression ratio, and shock strength. In addition, we also study the interplay of viscosity, magnetic field, and thermal conduction on the shock properties of the flow. We observe that thermal conduction plays a significant role in governing the properties of transonic accretion solutions. We show that shock-induced global accretion solutions persist for a wide range of model parameters and identify the boundary of the parameter space in the energy-angular momentum plane that admits standing shocks for different dissipation parameters (thermal conduction, radiative cooling). Moreover, we compute the limiting value of the conduction parameter, beyond which shock ceases to exist and found that it depends on the dissipation parameters (viscosity, magnetic field and cooling) and the spin of the black hole. We conclude the study by investigating the spectral energy distribution (SED) of the accretion disc and observe that increased thermal conduction and magnetic field strength lead to more luminous emission spectra from black hole sources. |
