The mass distribution of compact objects provides a fossil record that can be studied to uncover information on the late stages of massive star evolution , the supernova explosion mechanism , and the dense matter equation of state .
Observations of neutron star masses indicate a bimodal Gaussian distribution , while the observed black hole mass distribution decays exponentially for stellar-mass black holes .
We use these observed distributions to directly confront the predictions of stellar evolution models and the neutrino-driven supernova simulations of .
We find excellent agreement between the black hole and low-mass neutron star distributions created by these simulations and the observations .
We show that a large fraction of the stellar envelope must be ejected , either during the formation of stellar-mass black holes or prior to the implosion through tidal stripping due to a binary companion , in order to reproduce the observed black hole mass distribution .
We also determine the origins of the bimodal peaks of the neutron star mass distribution , finding that the low-mass peak ( centered at \sim 1.4 ~ { } M _ { \odot } ) originates from progenitors with M _ { ZAMS } \approx 9 - 18 ~ { } M _ { \odot } .
The simulations fail to reproduce the observed peak of high-mass neutron stars ( centered at \sim 1.8 ~ { } M _ { \odot } ) and we explore several possible explanations .
We argue that the close agreement between the observed and predicted black hole and low-mass neutron star mass distributions provides new promising evidence that these stellar evolution and explosion models are accurately capturing the relevant stellar , nuclear , and explosion physics involved in the formation of compact objects .