Why NS and BH mass distribition is bimodal?

TL;DR

This paper explains the bimodal distribution of neutron star and black hole masses through a magneto-rotational supernova mechanism and a soft neutron star equation of state, linking observed mass gaps to explosion physics.

Contribution

It proposes a specific physical mechanism and neutron star equation of state to account for the observed bimodal mass distribution of compact remnants.

Findings

Mass distribution can be explained by magneto-rotational supernovae.

Neutron stars have a limiting mass around 1.5-1.6 solar masses.

The mechanism links supernova physics to remnant mass distribution.

Abstract

The observed mass distribution for the compact remnants of massive stars (neutron stars and black holes) and its relationship to possible mechanisms for the ejection of the envelopes of type II and Ib/c supernovae is analyzed. The conclusion is drawn that this distribution can be obtained only by a magneto-rotational mechanism for the supernovae with sufficiently long time of the field amplification, and a soft equation of state for neutron stars with limiting masses \sim1.5-1.6M_\odot. Some consequences of this hypothesis are discussed.