Find the Gap: Black Hole Population Analysis with an Astrophysically Motivated Mass Function
Abstract
We introduce a novel black hole mass function which realistically models the physics of star formation and pair instability supernova with a minimal number of parameters. Applying this to all events in the LIGO-Virgo GWTC-2 catalog, we detect a peak at MBHMG = 74.8+4.3-8.0 MS, followed by a break in the mass function. Repeating the analysis without the black holes from the event GW190521, we find this feature at MBHMG = 55.4+3.0-6.1 MS. The latter result establishes the edge of the anticipated "black hole mass gap" at a value compatible with the expectation from standard stellar structure theory, while the former result is ~ 20MS higher, which would have far-reaching implications if confirmed. Using Bayesian techniques, we establish that our mass function fits a new catalog of black hole masses approximately as well as the pre-existing phenomenological mass functions. We also remark on the implications of these results for constraining or discovering new phenomena in nuclear and particle physics.