Explodability fluctuations of massive stellar cores enable asymmetric compact object mergers such as GW190814

Understand

The first three observing runs with Advanced LIGO and Virgo have resulted in the detection of binary black hole mergers (BBH) with highly unequal mass components, which are difficult to reconcile with standard formation paradigms.

• The most representative of these is GW190814, a highly asymmetric merger between a 23 M$_{\odot}$ black hole and a 2.6 M$_{\odot}$ compact object.
• Here, we explore recent results suggesting that a sizeable fraction of stars with pre-collapse carbon-oxygen core masses above 10 M$_{\odot}$, and extending up to at least 30 M$_{\odot}$, may produce objects inside the so-called lower mass gap that bridges the division between massive pulsars and BHs in Galactic X-ray binaries.
• We demonstrate that such an explosion landscape would naturally cause a fraction of massive binaries to produce GW190814-like systems instead of symmetric-mass BBHs.