The role of thermal pressure in jet launching

TL;DR

This paper proposes a unified thermally-launched jet model where shock-induced dissipation of accretion energy generates internal pressure that accelerates jets, potentially explaining relativistic outflows from compact objects.

Contribution

It introduces a novel two-stage jet launching mechanism based on thermal pressure and magnetic field interactions, expanding current understanding of jet formation.

Findings

Predicts higher mass accretion rates in brown dwarfs launching jets.

Suggests thermal pressure as a key driver in jet acceleration.

Proposes a double-stage process for relativistic jet formation.

Abstract

I present and discuss a unified scheme for jet launching that is based on stochastic dissipation of the accretion disk kinetic energy, mainly via shock waves. In this scheme, termed thermally-launched jet model, the kinetic energy of the accreted mass is transferred to internal energy, e.g., heat or magnetic energy. The internal energy accelerates a small fraction of the accreted mass to high speeds and form jets. For example, thermal energy forms a pressure gradient that accelerates the gas. A second acceleration stage is possible wherein the primary outflow stretches magnetic field lines. The field lines then reconnect and accelerate small amount of mass to very high speeds. This double-stage acceleration process might form highly relativistic jets from black holes and neutron stars. The model predicts that detail analysis of accreting brown dwarfs that launch jets will show the mass accretion rate to be larger than 10^{-9}-10^{-8} Mo/year, which is higher than present claims in the literature.