Dynamical Friction Modeling of Massive Black Holes in Cosmological Simulations and Effects on Merger Rate Predictions

Chen, Nianyi; Ni, Yueying; Tremmel, Michael; Di Matteo, Tiziana; Bird, Simeon; DeGraf, Colin; Feng, Yu

doi:10.48550/arxiv.2104.00021

Cited by 7 publications

(20 citation statements)

References 84 publications

(156 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Compared with BlueTides, we have changed the seeding scheme of SMBHs by drawing the BH seed mass from a power-law distribution instead of using a universal seed mass. Furthermore, we apply the dynamic friction model (tested and validated in Chen et al 2021) to allow the sinking and merger of SMBHs after a galaxy merger to be followed more accurately than with the earlier repositioning based model. We elaborate on our BH models in Section 3.…”

Section: Astrid Simulationmentioning

confidence: 99%

“…We instead use a sub-grid dynamical friction model (Chen et al 2021) to account for the unresolved frictional force exerted by the surrounding collisionless matter (stars and stellar-mass black holes) on SMBH dynamics. In this model, SMBHs gradually sink to the galaxy centre, as their relative velocity is dissipated by dynamical friction.…”

Section: Bh Dynamics and Mergersmentioning

confidence: 99%

“…Moreover, we can make a more physical prediction for BH mergers by calculating whether the (now well-defined) relative velocities of two SMBHs allow them to be gravitationally bound. The validation of our dynamical friction model in cosmological simulations was performed in Chen et al (2021). In this section, we briefly review the BH dynamics.…”

Section: Bh Dynamics and Mergersmentioning

confidence: 99%

“…We approximate 𝑓 (𝑣 𝑎 ) by the Maxwellian distribution (as, e.g. Binney & Tremaine 2008), and account for the neighbouring collisionless particles up to the range of the SPH kernel of the BH particle (see, Chen et al 2021, for more details). Eq.…”

Section: Dynamical Frictionmentioning

confidence: 99%

“…This term is motivated by the BH gaining momentum from the surrounding gas continuously, bringing the sinking of the BH with respect to the gas. It is a subdominant factor compared to the dynamical friction exerted by collisionless particles (Chen et al 2021).…”

Section: Gas Dragmentioning

confidence: 99%

See 4 more Smart Citations

The ASTRID simulation: the evolution of Supermassive Black Holes

Ni,

Di Matteo,

Bird

et al. 2021

Preprint

Self Cite

View full text Add to dashboard Cite

We present the evolution of black holes (BHs) and their relationship with their host galaxies in Astrid , a large-volume cosmological hydrodynamical simulation with box size 250 ℎ −1 Mpc containing 2 × 5500 3 particles evolved to 𝑧 = 3. Astrid statistically models BH gas accretion and AGN feedback to their environments, applies a power-law distribution for BH seed mass 𝑀 sd , uses a dynamical friction model for BH dynamics and executes a physical treatment of BH mergers. The BH population is broadly consistent with empirical constraints on the BH mass function, the bright end of the luminosity functions, and the time evolution of BH mass and accretion rate density. The BH mass and accretion exhibit a tight correlation with host stellar mass and star formation rate. We trace BHs seeded before 𝑧 > 10 down to 𝑧 = 3, finding that BHs carry virtually no imprint of the initial 𝑀 sd except those with the smallest 𝑀 sd , where less than 50% of them have doubled in mass. Gas accretion is the dominant channel for BH growth compared to BH mergers. With dynamical friction, Astrid predicts a significant delay for BH mergers after the first encounter of a BH pair, with a typical elapse time of about 200 Myrs. There are in total 4.5 × 10 5 BH mergers in Astrid at 𝑧 > 3, ∼ 10 3 of which have X-ray detectable EM counterparts: a bright kpc scale dual AGN with 𝐿 X > 10 43 erg s −1 . BHs with 𝑀 BH ∼ 10 7−8 𝑀 experience the most frequent mergers. Galaxies that host BH mergers are unbiased tracers of the overall 𝑀 BH − 𝑀 * relation. Massive (> 10 11 𝑀 ) galaxies have a high occupation number ( 10) of BHs, and hence host the majority of BH mergers.

show abstract

Section: Astrid Simulationmentioning

confidence: 99%

Section: Bh Dynamics and Mergersmentioning

confidence: 99%

Section: Bh Dynamics and Mergersmentioning

confidence: 99%

Section: Dynamical Frictionmentioning

confidence: 99%

Section: Gas Dragmentioning

confidence: 99%

See 3 more Smart Citations

The ASTRID simulation: the evolution of Supermassive Black Holes

Ni,

Di Matteo,

Bird

et al. 2021

Preprint

Self Cite

View full text Add to dashboard Cite

show abstract

Impact of gas spin and Lyman–Werner flux on black hole seed formation in cosmological simulations: implications for direct collapse

Bhowmick

Blecha

Torrey

et al. 2021

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

Direct collapse black holes (BH) are promising candidates for producing massive z ≳ 6 quasars, but their formation requires fine-tuned conditions. In this work, we use cosmological zoom simulations to study systematically the impact of requiring: 1) low gas angular momentum (spin), and 2) a minimum incident Lyman-Werner (LW) flux in order to form BH seeds. We probe the formation of seeds (with initial masses of Mseed ∼ 104 - 106M⊙/h) in halos with a total mass >3000 × Mseed and a dense, metal poor gas mass >5 × Mseed. Within this framework, we find that the seed-forming halos have a prior history of star formation and metal enrichment, but they also contain pockets of dense, metal poor gas. When seeding is further restricted to halos with low gas spins, the number of seeds formed is suppressed by factors of ∼6 compared to the baseline model, regardless of the seed mass. Seed formation is much more strongly impacted if the dense, metal poor gas is required to have a critical LW flux (Jcrit). Even for Jcrit values as low as 50 J21, no 8 × 105 M⊙/h seeds are formed. While lower mass (1.25 × 104, 1 × 105 M⊙/h) seeds do form, they are strongly suppressed (by factors of ∼10 − 100) compared to the baseline model at gas mass resolutions of ∼104 M⊙/h (with even stronger suppression at higher resolutions). As a result, BH merger rates are also similarly suppressed. Since early BH growth is dominated by mergers in our models, none of the seeds are able to grow to the supermassive regime (≳ 106 M⊙/h) by z = 7. Our results hint that producing the bulk of the z ≳ 6 supermassive BH population may require alternate seeding scenarios that do not depend on the LW flux, early BH growth dominated by rapid or super-Eddington accretion, or a combination of these possibilities.

show abstract

Gravitational waves from the remnants of the first stars in nuclear star clusters

Liu,

Bromm

2021

Preprint

View full text Add to dashboard Cite

We study Population III (Pop III) binary remnant mergers in nuclear star clusters (NSCs) with a semi-analytical approach for early structure formation based on halo merger trees, in which star formation and stellar feedback are modelled selfconsistently. Within this framework, we keep track of the dynamics of Pop III binary (compact object) remnants in their host galaxies during cosmic structure formation, and construct the population of Pop III binary remnants that fall into NSCs by dynamical friction of field stars. The subsequent evolution within NSCs is then derived from three-body encounters and gravitational-wave (GW) emission. We find that on average 7.5% of Pop III binary remnants will fall into the centres (< 3 pc) of galaxies that can host NSCs with masses above 10 5 M . About 5 − 50% of these binaries will merge at z > 0 in NSCs, including those with very large initial separations (up to 1 pc). The merger rate density (MRD) peaks at z ∼ 5 − 7 with ∼ 0.4 − 10 yr −1 Gpc −3 , comparable to the MRDs found in the binary stellar evolution channel. Low-mass ( 10 6 M ) NSCs formed at high redshifts (z 4.5) host most ( 90%) of our mergers, which mainly consist of black holes (BHs) with masses ∼ 40 − 85 M , similar to the most massive BHs found in LIGO events. Particularly, our model can produce events like GW190521 involving BHs in the standard mass gap for pulsational pairinstability supernovae with a MRD ∼ 0.01−0.09 yr −1 Gpc −3 at z ∼ 1, consistent with that inferred by LIGO (within the 90% confidence interval). We predict a promising detection rate ∼ 170 − 2700 yr −1 for planned 3rd-generation GW detectors such as the Einstein Telescope that can reach z ∼ 10.

show abstract

Dynamical Friction Modeling of Massive Black Holes in Cosmological Simulations and Effects on Merger Rate Predictions

Cited by 7 publications

References 84 publications

The ASTRID simulation: the evolution of Supermassive Black Holes

The ASTRID simulation: the evolution of Supermassive Black Holes

Impact of gas spin and Lyman–Werner flux on black hole seed formation in cosmological simulations: implications for direct collapse

Gravitational waves from the remnants of the first stars in nuclear star clusters

Contact Info

Product

Resources

About