Failed Supernovae Explain the Compact Remnant Mass Function

TL;DR

This paper proposes that failed supernovae, which produce black holes without bright explosions, naturally explain the observed black hole mass distribution and the missing high-mass red supergiant progenitors of Type IIP supernovae.

Contribution

It demonstrates that failed supernovae account for the black hole mass function and the gap between neutron star and black hole masses without fine-tuning the supernova mechanism.

Findings

Failed supernovae produce black holes with masses of 5-8 solar masses.

Failed supernovae can explain the observed black hole mass distribution.

Approximately 20% of supernova progenitors may end as failed supernovae.

Abstract

One explanation for the absence of higher mass red supergiants (16.5 Msun < M < 25Msun) as the progenitors of Type IIP supernovae (SNe) is that they die in failed SNe creating black holes. Simulations show that such failed SNe still eject their hydrogen envelopes in a weak transient, leaving a black hole with the mass of the star's helium core (5-8Msun). Here we show that this naturally explains the typical masses of observed black holes and the gap between neutron star and black hole masses without any fine-tuning of the SN mechanism beyond having it fail in a mass range where many progenitor models have density structures that make the explosions more likely to fail. There is no difficulty including this ~20% population of failed SNe in any accounting of SN types over the progenitor mass function. And, other than patience, there is no observational barrier to either detecting these black hole formation events or limiting their rates to be well below this prediction.