Transonic accretion and the analogue gravity in multi-component elliptical galaxies hosting pseudo-Schwarzschild black holes

TL;DR

This study investigates how multi-component galactic potentials influence transonic accretion flows and analogue gravity phenomena around non-rotating black holes using the vertical equilibrium disc model.

Contribution

It demonstrates that galactic potential significantly affects critical points, shock parameters, and acoustic surface gravity across various pseudo-Schwarzschild potentials.

Findings

Galactic potential impacts critical point locations.

Shock-allowed parameter space is altered by galactic potential.

Acoustic surface gravity varies with galactic potential.

Abstract

Low-angular-momentum, axisymmetric, inviscid accretion flows onto a black hole have been studied using the vertical equilibrium disc model, considering multiple pseudo-Schwarzschild potentials and two thermodynamic equations of state. A multi-component galactic potential-representing stellar, dark matter, and hot-gas contributions-is incorporated to assess environmental effects on the accretion dynamics. In our earlier work, it is found that the effect of multi-component galactic potential on the accretion flow onto a rotating black hole under similar framework of analysis, significantly varies over different standard disc models, being most pronounced in the vertical equilibrium (VE) disc model. Thus it may be interesting to find whether such variation occur for different choices of pseudo potentials too. To begin with, in this work we consider accretion flow onto a non-rotating blackhole with VE geometry. Through the analysis of transonic behaviour and eigenvalue-based critical point classification, we demonstrate that, for all selected black hole potentials, the galactic potential profoundly influences the locations of critical points, the shock-allowed parameter space, shock-location, shock-driven flow variables, and acoustic surface gravity.