Searches for gravitational waves from compact binary mergers, which to date have reported ∼100 observations, have previously ignored binaries whose components are consistent with the mass of neutron stars (1–2 M⊙) and have high dimensionless spin >0.05. While previous searches targeted sources that are representative of observed neutron star binaries in the Galaxy, it is already known that neutron stars can regularly be spun up to a dimensionless spin of ∼0.4, and in principle reach up to ∼0.7 before breakup would occur. Furthermore, there may be primordial black hole binaries or exotic formation mechanisms to produce light black holes. In these cases, it is possible for the binary constituent to be spun up beyond that achievable by a neutron star. A single detection of this type of source would reveal a novel formation channel for compact binaries. To determine whether there is evidence for any such sources, we use pycbc to conduct a targeted search of LIGO and Virgo data for light compact objects with high spin. Our analysis detects previously known observations GW170817 and GW200115; however, we report no additional mergers. The most significant candidate, not previously known, is consistent with the noise distribution, and so we constrain the merger rate of spinning light binaries.
Gravitational-wave detections are enabling measurements of the rate of coalescences of binaries composed of two compact objects—neutron stars and/or black holes. The coalescence rate of binaries containing neutron stars is further constrained by electromagnetic observations, including Galactic radio binary pulsars and short gamma-ray bursts. Meanwhile, increasingly sophisticated models of compact objects merging through a variety of evolutionary channels produce a range of theoretically predicted rates. Rapid improvements in instrument sensitivity, along with plans for new and improved surveys, make this an opportune time to summarise the existing observational and theoretical knowledge of compact-binary coalescence rates.
more » « less- NSF-PAR ID:
- 10362872
- Publisher / Repository:
- Springer Science + Business Media
- Date Published:
- Journal Name:
- Living Reviews in Relativity
- Volume:
- 25
- Issue:
- 1
- ISSN:
- 2367-3613
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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