Massachusetts Institute of Technology | 2020 Sep 02
Researchers suggest a novel process to explain the collision of a large black hole and a much smaller one.
A lopsided merger of two black holes may have an oddball origin story, according to a new study by researchers at MIT and elsewhere.A lopsided merger of two black holes may have unusual origins,
based on a reanalysis of LIGO data. Credit: MIT News
The merger was first detected on April 12, 2019 as a gravitational wave that arrived at the detectors of both LIGO ... and its Italian counterpart, Virgo. Scientists labeled the signal as GW190412 and determined that it emanated from a clash between two David-and-Goliath black holes, one three times more massive than the other. The signal marked the first detection of a merger between two black holes of very different sizes.
Now the new study ... shows that this lopsided merger may have originated through a very different process compared to how most mergers, or binaries, are thought to form.
It's likely that the more massive of the two black holes was itself a product of a prior merger between two parent black holes. The Goliath that spun out of that first collision may have then ricocheted around a densely packed "nuclear cluster" before merging with the second, smaller black hole -- a raucous event that sent gravitational waves rippling across space.
GW190412 may then be a second generation, or "hierarchical" merger, standing apart from other first-generation mergers that LIGO and Virgo have so far detected. ...
Astrophysical Implications of GW190412 as a Remnant of a Previous
Black-Hole Merger ~ Davide Gerosa, Salvatore Vitale, Emanuele Berti
- Physical Review Letters 125(10):1103 (04 Sep 2020) DOI: 10.1103/PhysRevLett.125.101103
- arXiv.org > astro-ph > arXiv:2005.04243 > 08 May 2020
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