Poking Holes: Looking for Gaps in LIGO/Virgo's Black Hole Population

Understand

Stellar evolution models predict the existence of a gap in the black hole mass spectrum from $\sim55 M_\odot - 120 M_\odot$ due to pair-instability supernovae (PISNe).

• We investigate the possible existence of such an "upper" mass gap in the second gravitational wave transient catalog (GWTC-2) by hierarchically modeling the astrophysical distribution of black hole masses.
• We extend the Truncated and Powerlaw+Peak mass distribution families to allow for an explicit gap in the mass distribution, and apply the extended models to GWTC-2.
• We find that with the Truncated model there is mild evidence favoring an upper mass gap with log Bayes Factor $\ln \mathcal{B} = 2.79$, inferring the lower and upper bounds at $56.12_{-4.38}^{+7.54} M_\odot$, and $103.74_{-6.32}^{+17.01} M_\odot$ respectively.