Outflow from unmagnetized shocked radiative transonic accretion disk around a black hole

TL;DR

This study uses hydrodynamic simulations to demonstrate that unmagnetized, shocked accretion disks around non-rotating black holes can produce sustained bipolar outflows reaching significant velocities without magnetic fields.

Contribution

It shows that such outflows can originate close to the black hole and reach terminal velocities up to 0.14c, with outflow rates depending on angular momentum.

Findings

Outflows originate near the black hole and propagate outward.

Maximum outflow velocity reaches 0.14c.

Outflow rate varies with angular momentum.

Abstract

We study outflow from an unmagnetized, shocked accretion disk around a non-rotating super-massive black hole using multidimensional hydrodynamics simulation with radiative cooling. We aim to investigate whether such shocked accretion flow can launch sustained collimated bipolar outflow reaching out to thousands of gravitational radii even in the absence of magnetic field and if yes, what terminal velocity can they achieve? We present the results of a few simulations of geometrically thick accretion flow with increasing specific angular momentum on a vertically elongated cylindrical domain. We show thatbipolar outflow from a region very close to the black hole is originating and propagating vertically out to our simulation domain boundary at around $2651$ Schwarzschild radius. The outflow attains a terminal velocity with a maximum value found to be $0.14c$ and the outflow rate depends on the angular momentum value of the accreting material. We also compute the self-Comptonized bremsstrahlung spectra for all the disk-jet runs.