The spin of the second-born black hole in coalescing binary black holes

By Y. Qin, Tassos Fragos, G. Meynet, Jeff Andrews, M. Sørensen, H. F. Song. Astronomy & Astrophysics, 2018

172 citations recorded by the source corpus.

Context. Various binary black hole formation channels have been proposed since the first gravitational event GW150914 was discovered by the Advanced Laser Interferometer Gravitational-Wave Observatory (AdLIGO). The immediate progenitor of the binary black hole is a close binary system composed of a black hole and a helium star, which can be the outcome of the classical isolated binary evolution through the common envelope, or alternatively of the massive close evolution through chemically homogeneous channel. Aims. We study the spin angular momentum evolution of the helium star in order to constrain the spin of the second-born black hole. This work focuses on the common envelope formation channel, however, some of our conclusions are also relevant for the chemically homogeneous evolution channel. Methods. We perform detailed stellar structure and binary evolution calculations that take into account, mass-loss, internal differential rotation, and tidal interactions between the helium star and the black hole companion, where we also calculate the strength of the tidal interactions from first principles based on the structure of the helium stars. We systematically explore the parameter space of initial binary properties, including initial black hole and helium star masses, initial rotation of the helium star as well as metallicity. Results. We argue that the natal spin of the first-born black hole through the common envelope scenario is negligible (≲0.1), and therefore the second-born black hole’s spin dominates the measured effective spin, χeff, from gravitational wave events of double black hole mergers. We find that tides can be only important when orbital periods are shorter than 2 days. Upon core collapse, the helium star produces a black hole (the second-born black hole in the system) with a spin that can span the entire range from zero to maximally spinning. We show that the bimodal distribution of the spin of the second-born black hole obtained in recent papers is mainly due to oversimplifying assumptions. We find an anti-correlation between the merging timescale of the two black holes, Tmerger, and the effective spin χeff. Finally, we provide new prescriptions for the tidal coefficient E2 for both H-rich and the He-rich stars. Conclusions. To understand the spin of the second-born black hole, careful treatment of both tides and stellar winds is needed. We predict that, with future improvements to AdLIGO’s sensitivity, the sample of merging binary black hole systems will show an overdensity of sources with positive but small χeff originating from lower-mass black hole mergers born at low redshift.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/a571b3716af010f8a4c17c1bcaaab182167032ae

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

In Nuclear and High Energy Physics

Citations in the corpus

One Channel to Rule Them All? Constraining the Origins of Binary Black Holes Using Multiple Formation Pathways (2020, methodology): “…BH is spinning depends on the post-CE separation, and thus the CE efficiency; lower CE efficiencies will lead to tighter post-CE binaries, increasing the effect of tides and therefore increasing the natal spin of the second-born BH (Zaldarriaga et al. 2018; Qin et al. 2018; Bavera et al. 2020a).”
The origin of spin in binary black holes (2019, methodology): “When using detailed models to simulate the binary evolution and the stellar structure of the two components, Qin et al. (2018) did not reproduce this prediction of a bimodal distribution of spins.”
GW231123: A Binary Black Hole Merger with Total Mass 190–265 M⊙ (2025, unknown): “…the BHs spinning, due to tidal synchronization or accretion-induced spin up, and so bi-naries with masses and spins like those inferred from GW231123 are difficult to form (Belczynski et al. 2020; Qin et al. 2018; Fuller & Ma 2019; Bavera et al. 2020; Belczynski et al. 2020; van Son et al. 2020).”
Evolutionary roads leading to low effective spins, high black hole masses, and O1/O2 rates for LIGO/Virgo binary black holes (2017, background): “(15)) resembles the Qin et al. (2018) scheme and allows for a broad range of BH spin magnitudes if the WR star that is forming a BH is subject to strong tidal interactions.”
Binary Black Hole Population Properties Inferred from the First and Second Observing Runs of Advanced LIGO and Advanced Virgo (2018, methodology): “While we have modeled the spins independently, correlations from binary evolution and stellar collapse are possible(Belczynski et al. 2017; Gerosa et al. 2018; Qin et al. 2018; Arca Sedda & Benacquista 2019; Postnov & Kuranov 2019).”
Most Black Holes Are Born Very Slowly Rotating (2019, methodology): “In each of these models, tidal spin-up and mass transfer is included via the prescriptions of Qin et al. (2018a).”
GWTC-2.1: Deep extended catalog of compact binary coalescences observed by LIGO and Virgo during the first half of the third observing run (2021, unknown): “Even if single stars form BHs with low spins [244], BHs in binaries may still develop high spins because of mass transfer [248], tidal interactions [242,249,250], or chemically homogeneous evolution [251,252].”