LIGO Scientific Collaboration, Virgo Collaboration, KAGRA Collaboration, Duval, H., Romero-Rodríguez, A., Sevrin, A., & Turbang, K. (2024). Observation of Gravitational Waves from the Coalescence of a $2.5\text{-}4.5~M_\odot$ Compact Object and a Neutron Star. The Astrophysical Journal Letters , 970(2), Article L34. https://doi.org/10.3847/2041-8213/ad5beb

@article{a61752efc9ed474aa21027e95bef0394,
title = "Observation of Gravitational Waves from the Coalescence of a \$2.5\textbackslash{}text\{-\}4.5\textasciitilde{}M\_\textbackslash{}odot\$ Compact Object and a Neutron Star",
abstract = " We report the observation of a coalescing compact binary with component masses \$2.5\textbackslash{}text\{-\}4.5\textasciitilde{}M\_\textbackslash{}odot\$ and \$1.2\textbackslash{}text\{-\}2.0\textasciitilde{}M\_\textbackslash{}odot\$ (all measurements quoted at the 90\% credible level). The gravitational-wave signal GW230529\_181500 was observed during the fourth observing run of the LIGO-Virgo-KAGRA detector network on 2023 May 29 by the LIGO Livingston Observatory. The primary component of the source has a mass less than \$5\textasciitilde{}M\_\textbackslash{}odot\$ at 99\% credibility. We cannot definitively determine from gravitational-wave data alone whether either component of the source is a neutron star or a black hole. However, given existing estimates of the maximum neutron star mass, we find the most probable interpretation of the source to be the coalescence of a neutron star with a black hole that has a mass between the most massive neutron stars and the least massive black holes observed in the Galaxy. We provisionally estimate a merger rate density of \$55\textasciicircum{}\{+127\}\_\{-47\}\textasciitilde{}\textbackslash{}text\{Gpc\}\textasciicircum{}\{-3\}\textbackslash{},\textbackslash{}text\{yr\}\textasciicircum{}\{-1\}\$ for compact binary coalescences with properties similar to the source of GW230529\_181500; assuming that the source is a neutron star-black hole merger, GW230529\_181500-like sources constitute about 60\% of the total merger rate inferred for neutron star-black hole coalescences. The discovery of this system implies an increase in the expected rate of neutron star-black hole mergers with electromagnetic counterparts and provides further evidence for compact objects existing within the purported lower mass gap. ",
keywords = "astro-ph.HE, gr-qc",
author = "\{LIGO Scientific Collaboration\} and \{Virgo Collaboration\} and \{KAGRA Collaboration\} and Hannah Duval and Alba Romero-Rodr{\'i}guez and Alexandre Sevrin and Kevin Turbang",
note = "45 pages (10 pages author list, 13 pages main text, 1 page acknowledgements, 13 pages appendices, 8 pages bibliography), 17 figures, 16 tables. Update to match version published in The Astrophysical Journal Letters. Data products available from https://zenodo.org/records/10845779",
year = "2024",
month = jul,
day = "26",
doi = "10.3847/2041-8213/ad5beb",
language = "English",
volume = "970",
journal = " The Astrophysical Journal Letters ",
issn = "2041-8205",
publisher = "IOP Publishing Ltd.",
number = "2",
}