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arXiv · 2106.00605

Detection of LIGO-Virgo binary black holes in the pair-instability mass gap

Brendan O'Brien·Marek Szczepanczyk·V. Gayathri·Imre Bartos·Gabriele Vedovato·Giovanni Prodi·Guenakh Mitselmakher·Sergey Klimenko
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Abstract

By probing the population of binary black hole (BBH) mergers detected by LIGO-Virgo, we can infer properties about the underlying black hole formation channels. A mechanism known as pair-instability (PI) supernova is expected to prevent the formation of black holes from stellar collapse with mass greater than $\sim 40-65\,M_\odot$ and less than $\sim 120\,M_\odot$. Any BBH merger detected by LIGO-Virgo with a component black hole in this gap, known as the PI mass gap, likely originated from an alternative formation channel. Here, we firmly establish GW190521 as an outlier to the stellar-mass BBH population if the PI mass gap begins at or below $65\, M_{\odot}$. In addition, for a PI lower boundary of $40-50\, M_{\odot}$, we find it unlikely that the remaining distribution of detected BBH events, excluding GW190521, is consistent with the stellar-mass population.

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Brendan O'Brien, Marek Szczepanczyk, V. Gayathri, Imre Bartos, Gabriele Vedovato, Giovanni Prodi, Guenakh Mitselmakher, Sergey Klimenko. 2021-06-01. Detection of LIGO-Virgo binary black holes in the pair-instability mass gap. https://doi.org/10.1103/physrevd.104.082003

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