Effects of the core-collapse supernova ejecta impact on a rapidly rotating massive companion star

TL;DR

This study examines how supernova ejecta impact and strip mass from rapidly rotating massive companion stars in close binaries, significantly affecting their rotational velocities and potentially stripping hydrogen envelopes, with implications for observed high-mass X-ray binaries.

Contribution

It provides the first detailed simulation of supernova ejecta effects on rapidly rotating massive companions, highlighting increased mass stripping and rotational velocity reduction.

Findings

Stripped mass doubles in rotating companions compared to non-rotating ones.

In close binaries, stripped mass can reach up to ~1 solar mass.

Rotational velocity decreases significantly when stripped mass exceeds ~1 solar mass.

Abstract

We investigate the effects of the core-collapse supernova ejecta on a rapidly rotating and massive companion star. We show that the stripped mass raises by twice when compare with a massive but non-rotating companion star. In close binaries with orbital periods of about 1 day, the stripped masses reach up to $\sim 1 M_\odot$. By simulating the evolutions of the rotational velocities of the massive companion stars based on different stripped masses, we find that the rotational velocity decreases greatly for stripped mass that is higher than about $1 M_\odot$. Of all the known high mass X-ray binaries (HMXBs), Cygnus X-3 and 1WGA J0648.024418 have the shortest orbital periods of 0.2 and 1.55 days, respectively. The optical counterpart of the former is a Wolf-Rayet star, whereas it is a hot subdwarf for the latter. Applying our model to the two HMXBs, we suggest that the hydrogen-rich envelopes of their optical counterparts may have been stripped by CCSN ejecta.