The response of a red supergiant to a common envelope jets supernova (CEJSN) impostor event

TL;DR

This study models how a red supergiant star reacts to energy injection and mass loss caused by jets from a neutron star during a common envelope supernova impostor event, predicting prolonged, bright transient phenomena.

Contribution

It provides a one-dimensional simulation of RSG response to jet-driven energy and mass removal based on previous 3D hydrodynamical models, exploring implications for transient events.

Findings

RSG envelope expands significantly with ~1e47-1e48 erg energy injection.

Neutron star remains inside the inflated envelope, launching prolonged jets.

Resulting transients could last months to years with luminosities over 10^8 solar luminosities.

Abstract

Using a one-dimensional stellar evolution code we simulate the response of a red supergiant (RSG) star to injection of energy and to mass removal. We take the values of the energy that we inject and the mass that we remove according to our previous three-dimensional hydrodynamical simulations of a neutron star (NS) on a highly eccentric orbit that enters the envelope of an RSG star for half a year and launches jets as it accretes mass via an accretion disk. We find that for injected energies of ~1e47-1e48 erg and removed mass of ~0.03-0.6Mo the RSG envelope expands to a large radius. Therefore, we expect the NS to continue to orbit inside this massive inflated envelope for several more months, up to about twice the initial RSG radius, to continue to accrete mass and launch jets for a prolonged period. Although these late jets are weaker than the jets that the NS launches while inside the original RSG envelope, the late jets might actually be more influential on the light curve, leading to a long, several months to few years, and bright, about >10^8Lo, transient event. The RSG returns to more or less a relaxed structure after about ten years, and so another transient event might occur in the next periastron passage of the NS. Our results add to the already rich variety of jet-driven explosions/outbursts that might account for many puzzling transient events.