Radiatively driven, time dependent bipolar outflows

TL;DR

This paper investigates how time-dependent radiation from accretion discs around black holes influences bipolar jet outflows, revealing that disc oscillations can generate shocks and transient features in jets.

Contribution

It introduces a semi-analytical model combined with a TVD code to study time-dependent radiatively driven jets with variable disc radiation and oscillations.

Findings

Disc oscillations induce internal shocks near the jet base.

Time-dependent radiation causes non-stationary shocks in jets.

Jet solutions vary with disc parameters and geometry.

Abstract

We study the radiatively driven fluid jets around a non-rotating black hole. The radiation arising from the inner compact corona and outer sub-Keplerian part of the disc accelerates the jets. We obtain the steady state, semi-analytical, radiatively driven outflow solutions. The thermodynamics of the outflow is described by a variable adiabatic index equation of state. We develop a TVD routine to investigate the time dependent behaviour of the radiatively driven bipolar outflow. We inject with flow variables from the steady state outflow solutions in the TVD code and allow the code to settle into steady state and match the numerical results with the steady state solution. The radiation arising out of the accretion disc can provide a wide range of jet solutions, depending upon parameters like the intensity of disc, location of the inner corona etc. We induce the time dependence of the radiation field by inducing oscillation of the inner corona of the accretion disc. The radiation field then makes the bipolar outflow time dependent. We show that a non-steady radiation field arising out of disc oscillations can generate the internal shocks closer to the jet base. Depending on the disc geometry, there might be transient shocks in the jet and there might be multiple non-stationary shocks in the jet, which are of much interest in jet physics.