Most Black Holes Are Born Very Slowly Rotating

By J. Fuller, Linhao Ma. Astrophysical Journal, 2019

233 citations recorded by the source corpus.

The age of gravitational-wave astronomy has begun, and black hole (BH) mergers detected by the Laser Interferometer Gravitational-Wave Observatory (LIGO) are providing novel constraints on massive star evolution. A major uncertainty in stellar theory is the angular momentum (AM) transport within the star that determines its core rotation rate and the resulting BH’s spin. Internal rotation rates of low-mass stars measured from asteroseismology prove that AM transport is efficient, suggesting that massive stellar cores may rotate slower than prior expectations. We investigate AM transport via the magnetic Tayler instability, which can largely explain the rotation rates of low-mass stars and white dwarfs. Implementing an updated AM transport prescription into models of high-mass stars, we compute the spins of their BH remnants. We predict that BHs born from single stars rotate very slowly, with a ∼ 10−2, regardless of initial rotation rate, possibly explaining the low χeff of most BH binaries detected by LIGO thus far. A limited set of binary models suggests slow rotation for many binary scenarios as well, although homogeneous evolution and tidal spin-up of post-common-envelope helium stars can create moderate or high BH spins. We make predictions for the values of χeff in future LIGO events, and we discuss implications for engine-powered transients.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/a3d72e70e909fae04b418181f805ac855d163410

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

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).”
The origin of spin in binary black holes (2019, methodology): “This leads to very slowly spinning BHs (a1 ' 0) as was shown by Qin et al. (2018; see also Fuller & Ma 2019).”
COSMIC Variance in Binary Population Synthesis (2019, result): “This is in contrast to newer work (e.g., Fuller & Ma 2019) suggesting that the Taylor-Spruit magnetic dynamo may allow for extremely efficient angular momentum transport through the envelopes of massive stars, producing BHs with dimensionless Kerr spin parameters a/M ∼ 0.01.”
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].”
One Channel to Rule Them All? Constraining the Origins of Binary Black Holes Using Multiple Formation Pathways (2020, background): “Variations in the natal spin magnitudes act as a proxy for the efficiency of angular momentum transport in massive stars; if angular momentum is efficiently transported from the core to the envelope, the birth spins of BHs are predicted to be low (e.g., Fuller & Ma 2019).”
Evolutionary roads leading to low effective spins, high black hole masses, and O1/O2 rates for LIGO/Virgo binary black holes (2017, methodology): “Super-efficient angular momentum transport is based on the Tayler-Spruit dynamo, which is subsequently modified to include stronger magnetic field generation that allows for more efficient angular momentum transport (Fuller et al. 2019; Ma & Fuller 2019; Fuller & Ma 2019).”