Rapid Black Hole Spin-down by Thick Magnetically Arrested Disks

Lowell, Beverly; Jacquemin-Ide, Jonatan; Tchekhovskoy, Alexander; Duncan, Alex

doi:10.48550/arxiv.2302.01351

Cited by 7 publications

(32 citation statements)

References 69 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In reality, the BH spins up by accreting angular momentum from the infalling gas, and spins down by utilizing its rotational energy to launch the jets. These effects are particularly important when the BH spin is far from the equilibrium spin of a ≈ 0.1 (Lowell et al 2023). In a companion paper (Jacquemin-Ide et al 2023), we show that taking into account the BH spin evolution does not change our conclusion that disfavors rapidly spinning BHs.…”

Section: Discussionmentioning

confidence: 49%

“…is defined as the EM energy flux leaving the BH, where  m is the mass accretion rate onto the BH. The jet launching efficiency solely depends on the dimensionless BH spin (Lowell et al 2023)…”

Section: Introductionmentioning

confidence: 99%

“…Equation (5) dictates that in this case a ; 0.48. Lowell et al (2023) argued that a cooled disk would have a milder equilibrium spin, a = 0.3, compared to a noncooled disk in which the equilibrium spin is a = 0.1. Thus, the jet wobbling motion might probe the cooling state of collapsar accretion disks.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Collapsar Black Holes Are Likely Born Slowly Spinning

Gottlieb,

Jacquemin-Ide,

Lowell

et al. 2023

ApJL

View full text Add to dashboard Cite

Collapsing stars constitute the main black hole (BH) formation channel, and are occasionally associated with the launch of relativistic jets that power γ-ray bursts (GRBs). Thus, collapsars offer an opportunity to infer the natal (before spin-up/down by accretion) BH spin directly from observations. We show that once the BH saturates with a large-scale magnetic flux, the jet power is dictated by the BH spin and mass accretion rate. Core-collapse simulations by Halevi et al. and GRB observations favor stellar density profiles that yield an accretion rate of m ̇ ≈ 10 − 2 M ⊙ s − 1 , weakly dependent on time. This leaves the spin as the main factor that governs the jet power. By comparing the jet power to characteristic GRB luminosities, we find that the majority of BHs associated with jets are likely born slowly spinning with a dimensionless spin of a ≃ 0.2, or a ≃ 0.5 for wobbling jets, with the main uncertainty originating in the unknown γ-ray radiative efficiency. This result could be applied to the entire core-collapse BH population, unless an anticorrelation between the stellar magnetic field and angular momentum is present. In a companion paper, Jacquemin-Ide et al., we show that regardless of the natal spin, the extraction of BH rotational energy leads to spin-down to a ≲ 0.2, consistent with gravitational-wave observations. We verify our results by performing the first 3D general-relativistic magnetohydrodynamic simulations of collapsar jets with characteristic GRB energies, powered by slowly spinning BHs. We find that jets of typical GRB power struggle to escape from the star, providing the first numerical indication that many jets fail to generate a GRB.

show abstract

Section: Discussionmentioning

confidence: 49%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Collapsar Black Holes Are Likely Born Slowly Spinning

Gottlieb,

Jacquemin-Ide,

Lowell

et al. 2023

ApJL

View full text Add to dashboard Cite

show abstract

“…However, such conservative mass transfer is not as efficient as nonconservative mass transfer in shrinking the orbit, and so this scenario may not contribute much to the merger rate. Significant accretion would also generally spin up the BH (although see, e.g., Lowell et al 2023), while the spin of the primary BH in GW190814 is tightly constrained to be near zero.…”

Section: Discussionmentioning

confidence: 99%

The Role of Natal Kicks in Forming Asymmetric Compact Binary Mergers

Fishbach

Kimball

et al. 2023

ApJ

View full text Add to dashboard Cite

In their most recent observing run, the LIGO-Virgo-KAGRA Collaboration observed gravitational waves from compact binary mergers with highly asymmetric mass ratios, including both binary black holes (BBHs) and neutron star-black holes (NSBHs). It appears that NSBHs with mass ratios q ≃ 0.2 are more common than equally asymmetric BBHs, but the reason for this remains unclear. We use the binary population synthesis code cosmic to investigate the evolutionary pathways leading to the formation and merger of asymmetric compact binaries. We find that within the context of isolated binary stellar evolution, most asymmetric mergers start off as asymmetric stellar binaries. Because of the initial asymmetry, these systems tend to first undergo a dynamically unstable mass transfer phase. However, after the first star collapses into a compact object, the mass ratio is close to unity and the second phase of mass transfer is usually stable. According to our simulations, this stable mass transfer fails to shrink the orbit enough on its own for the system to merge. Instead, the natal kick received by the second-born compact object during its collapse is key in determining how many of these systems can merge. For the most asymmetric systems with mass ratios of q ≤ 0.1, the merging systems in our models receive an average kick magnitude of 255 km s−1 during the second collapse, while the average kick for non-merging systems is 59 km s−1. Because lower mass compact objects, like neutron stars, are expected to receive larger natal kicks than higher mass BHs, this may explain why asymmetric NSBH systems merge more frequently than asymmetric BBH systems.

show abstract

“…Since the BZ mechanism powers a jet by extracting BH spin energy, if the process continues long enough, a BH could continuously spin down and equilibrate near a spin value a * ≈ 0. This has been explicitly demonstrated via general relativistic magnetohydrodynamic (GRMHD) simulations of radiatively inefficient, geometrically thick MAD models (McKinney et al 2012;Tchekhovskoy et al 2012;Narayan et al 2022;Lowell et al 2023). Several recent publications have begun to study the implications of this spin-down effect for BH populations over cosmic time.…”

Section: Introductionmentioning

confidence: 97%

Recipes for Jet Feedback and Spin Evolution of Black Holes with Strongly Magnetized Super-Eddington Accretion Disks

Ricarte,

Narayan,

Curd

2023

ApJL

View full text Add to dashboard Cite

A spinning black hole (BH) accreting from a disk of strongly magnetized plasma via a magnetically arrested disk is known to produce an efficient electromagnetic jet powered by the BH’s spin energy. We present general relativistic radiative magnetohydrodynamic simulations of magnetically arrested systems covering a range of sub- to super-Eddington accretion rates. Using the numerical results from these simulations, we develop formulae to describe the magnetization, jet efficiency, and spin evolution of an accreting BH as a function of its spin and accretion rate. A BH with near-Eddington accretion experiences a mild degree of spin-down because of angular momentum loss through the jet, leading to an equilibrium spin of 0.8 rather than 1.0 at the Eddington limit. As the accretion rate increases above Eddington, the spin-down effect becomes progressively stronger, ultimately converging on previous predictions based on nonradiative simulations. In particular, spin evolution drives highly super-Eddington systems toward a BH spin near zero. The formulae developed in this letter may be applied to galaxy- and cosmological-scale simulations that include BHs. If magnetically arrested disk accretion is common among supermassive BHs, the present results have broad implications for active galactic nucleus feedback and cosmological spin evolution.

show abstract

Rapid Black Hole Spin-down by Thick Magnetically Arrested Disks

Cited by 7 publications

References 69 publications

Collapsar Black Holes Are Likely Born Slowly Spinning

Collapsar Black Holes Are Likely Born Slowly Spinning

The Role of Natal Kicks in Forming Asymmetric Compact Binary Mergers

Recipes for Jet Feedback and Spin Evolution of Black Holes with Strongly Magnetized Super-Eddington Accretion Disks

Contact Info

Product

Resources

About