Aspherical supernova explosions and formation of compact black hole low-mass X-ray binaries

TL;DR

This paper proposes a new evolutionary pathway for black-hole low-mass X-ray binaries involving aspherical supernova explosions that strip the secondary star's mass, leading to the formation of compact binaries with low-mass donors.

Contribution

It introduces a novel scenario where aspherical supernova explosions reduce the secondary star's mass, explaining the observed properties of BHLMXBs.

Findings

Secondary stars can be initially intermediate-mass and lose mass during aspherical SN explosions.

Magnetic braking can shrink the orbit, enabling mass transfer and formation of BHLMXBs.

The proposed model aligns with observed low effective temperatures of donor stars.

Abstract

It has been suggested that black-hole low-mass X-ray binaries (BHLMXBs) with short orbital periods may have evolved from BH binaries with an intermediate-mass secondary, but the donor star seems to always have higher effective temperatures than measured in BHLMXBs (Justham, Rappaport & Podsiadlowski 2006). Here we suggest that the secondary star is originally an intermediate-mass ($\sim 2-5 M_{\sun}$) star, which loses a large fraction of its mass due to the ejecta impact during the aspherical SN explosion that produced the BH. The resulted secondary star could be of low-mass ($\la 1 M_{\sun}$). Magnetic braking would shrink the binary orbit, drive mass transfer between the donor and the BH, producing a compact BHLMXB.