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arXiv · 2006.13219

Interpreting LIGO/Virgo "Mass-Gap" events as lensed Neutron Star-Black Hole binaries

Tom Broadhurst·Jose M. Diego·George F. Smoot
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Abstract

Gravitational lensing allows the detection of binary black holes (BBH) at cosmological distances with chirp masses that appear to be enhanced by $1+z$ in the range $1 95\%$), from which we infer a factor $\simeq 5$ higher intrinsic rate of NSBH events than BBH events, reflecting a higher proportion of neutron stars formed by early star formation. We predict a distinctive locus for lensed NSBH events in the observed binary mass plane, spanning $1<z<4$ with a narrow mass ratio, $q \simeq 0.2$, that can be readily tested when the waveform data are unlocked. All such events may show disrupted NS emission and are worthy of prompt follow-up as the high lensing magnification means EM detections are not prohibitive despite the high redshifts that we predict. Such lensed NSBH events provide an exciting prospect of directly charting the history of coalescing binaries via the cosmological redshift of their waveforms, determined relative to the characteristic mass of the neutron star member.

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Tom Broadhurst, Jose M. Diego, George F. Smoot. 2020-06-24. Interpreting LIGO/Virgo "Mass-Gap" events as lensed Neutron Star-Black Hole binaries. https://arxiv.org/abs/2006.13219

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