Mechanical feedback effects on primordial black hole accretion

Context. Dark matter may consist, at least partially, of primordial black holes formed during the radiation-dominated era. The radiation produced by accretion onto primordial black holes leaves characteristic signatures on the properties of the medium at high redshift, before and after hydrogen recombination. Therefore, reliable modeling of accretion onto these objects is required to obtain robust constraints on their abundance. Aims. We investigate the effect of mechanical feedback, that is, the impact of outflows (winds and– or –jets) on the medium, on primordial black hole accretion, and thereby on the associated radiation. Methods. Using analytical and numerical calculations, we studied for the first time the possibility that outflows can reduce the accretion rate of primordial black holes with masses similar to those detected by the LIGO-Virgo collaboration. Results. Despite the complexity of the accretion rate evolution, mechanical feedback is useful in to significantly reducing the primordial black hole accretion rate, at least by one order of magnitude, when outflows are aligned with the motion of the compact object. If the outflow is perpendicular to the direction of motion, the effect is less important, but it is still non-negligible. Conclusions. Outflows from primordial black holes, even rather weak ones, can significantly decrease the accretion rate, effectively weakening abundance constraints on these objects. Our results motivate further numerical simulations with a more realistic setup, which would yield more precise quantitative predictions.

Download Full-text

X-ray properties of reverberation-mapped AGNs with super-Eddington accreting massive black holes

Proceedings of the International Astronomical Union ◽

10.1017/s1743921320002756 ◽

2019 ◽

Vol 15 (S356) ◽

pp. 143-143

Author(s):

Jaya Maithil ◽

Michael S. Brotherton ◽

Bin Luo ◽

Ohad Shemmer ◽

Sarah C. Gallagher ◽

...

Keyword(s):

Black Holes ◽

Black Hole ◽

Accretion Rate ◽

Time Lags ◽

Black Hole Mass ◽

Host Galaxies ◽

Massive Black Holes ◽

X Ray ◽

Photon Index ◽

The Impact

AbstractActive Galactic Nuclei (AGN) exhibit multi-wavelength properties that are representative of the underlying physical processes taking place in the vicinity of the accreting supermassive black hole. The black hole mass and the accretion rate are fundamental for understanding the growth of black holes, their evolution, and the impact on the host galaxies. Recent results on reverberation-mapped AGNs show that the highest accretion rate objects have systematic shorter time-lags. These super-Eddington accreting massive black holes (SEAMBHs) show BLR size 3-8 times smaller than predicted by the Radius-Luminosity (R-L) relationship. Hence, the single-epoch virial black hole mass estimates of highly accreting AGNs have an overestimation of a factor of 3-8 times. SEAMBHs likely have a slim accretion disk rather than a thin disk that is diagnostic in X-ray. I will present the extreme X-ray properties of a sample of dozen of SEAMBHs. They indeed have a steep hard X-ray photon index, Γ, and demonstrate a steeper power-law slope, ασx.

Download Full-text

The Merger Rate of Black Holes in a Primordial Black Hole Cluster

Physics ◽

10.3390/physics3020026 ◽

2021 ◽

Vol 3 (2) ◽

pp. 372-378

Author(s):

Viktor D. Stasenko ◽

Alexander A. Kirillov

Keyword(s):

Black Holes ◽

Black Hole ◽

Mass Spectrum ◽

Star Clusters ◽

Primordial Black Hole ◽

Primordial Black Holes ◽

Central Black Hole ◽

Solar Mass ◽

Merger Rate

In this paper, the merger rate of black holes in a cluster of primordial black holes (PBHs) is investigated. The clusters have characteristics close to those of typical globular star clusters. A cluster that has a wide mass spectrum ranging from 10−2 to 10M⊙ (Solar mass) and contains a massive central black hole of the mass M•=103M⊙ is considered. It is shown that in the process of the evolution of cluster, the merger rate changed significantly, and by now, the PBH clusters have passed the stage of active merging of the black holes inside them.

Download Full-text

On Primordial Black Holes and secondary gravitational waves generated from inflation with solo/multi-bumpy potential

Chinese Physics C ◽

10.1088/1674-1137/ac42bd ◽

2021 ◽

Author(s):

Rui feng Zheng ◽

Jia ming Shi ◽

Taotao Qiu

Keyword(s):

Black Holes ◽

Black Hole ◽

Gravitational Waves ◽

Power Spectra ◽

Small Scale ◽

Primordial Black Hole ◽

Primordial Black Holes ◽

Slow Roll ◽

Spherical Collapse ◽

Scalar Perturbations

Abstract It is well known that primordial black hole (PBH) can be generated in inflation process of the early universe, especially when the inflaton field has some non-trivial features that could break the slow-roll condition. In this paper, we investigate a toy model of inflation with bumpy potential, which has one or several bumps. We found that potential with multi-bump can give rise to power spectra with multi peaks in small-scale region, which can in turn predict the generation of primordial black holes in various mass ranges. We also consider the two possibilities of PBH formation by spherical collapse and elliptical collapse. And discusses the scalar-induced gravitational waves (SIGWs) generated by the second-order scalar perturbations.

Download Full-text

Cosmological black holes are not described by the Thakurta metric: LIGO-Virgo bounds on PBHs remain unchanged

The European Physical Journal C ◽

10.1140/epjc/s10052-021-09803-4 ◽

2021 ◽

Vol 81 (11) ◽

Author(s):

Gert Hütsi ◽

Tomi Koivisto ◽

Martti Raidal ◽

Ville Vaskonen ◽

Hardi Veermäe

Keyword(s):

Black Holes ◽

Black Hole ◽

Dark Matter ◽

Compact Object ◽

Compact Objects ◽

Primordial Black Hole ◽

Mass Growth ◽

Black Hole Binaries ◽

Physical Conditions ◽

Accretion Physics

AbstractWe show that the physical conditions which induce the Thakurta metric, recently studied by Bœhm et al. in the context of time-dependent black hole masses, correspond to a single accreting compact object in the entire Universe filled with isotropic non-interacting dust. In such a case, accretion physics is not local but tied to the properties of the whole Universe. We show that radiation, primordial black holes or particle dark matter cannot produce the specific energy flux required for supporting the mass growth of the compact objects described by the Thakurta metric. In particular, this solution does not apply to black hole binaries. We conclude that compact dark matter candidates and their mass growth cannot be described by the Thakurta metric, and thus existing constraints on the primordial black hole abundance from the LIGO-Virgo and the CMB measurements remain valid.

Download Full-text

Probing black hole accretion tracks, scaling relations, and radiative efficiencies from stacked X-ray active galactic nuclei

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stz3522 ◽

2019 ◽

Vol 493 (1) ◽

pp. 1500-1511 ◽

Cited By ~ 9

Author(s):

Francesco Shankar ◽

David H Weinberg ◽

Christopher Marsden ◽

Philip J Grylls ◽

Mariangela Bernardi ◽

...

Keyword(s):

Black Holes ◽

Black Hole ◽

Selection Bias ◽

Stellar Mass ◽

Supermassive Black Holes ◽

Independent Evidence ◽

X Ray ◽

Black Hole Accretion ◽

Black Hole Masses ◽

Hole Accretion

ABSTRACT The masses of supermassive black holes at the centres of local galaxies appear to be tightly correlated with the mass and velocity dispersions of their galactic hosts. However, the local Mbh–Mstar relation inferred from dynamically measured inactive black holes is up to an order-of-magnitude higher than some estimates from active black holes, and recent work suggests that this discrepancy arises from selection bias on the sample of dynamical black hole mass measurements. In this work, we combine X-ray measurements of the mean black hole accretion luminosity as a function of stellar mass and redshift with empirical models of galaxy stellar mass growth, integrating over time to predict the evolving Mbh–Mstar relation. The implied relation is nearly independent of redshift, indicating that stellar and black hole masses grow, on average, at similar rates. Matching the de-biased local Mbh–Mstar relation requires a mean radiative efficiency ε ≳ 0.15, in line with theoretical expectations for accretion on to spinning black holes. However, matching the ‘raw’ observed relation for inactive black holes requires ε ∼ 0.02, far below theoretical expectations. This result provides independent evidence for selection bias in dynamically estimated black hole masses, a conclusion that is robust to uncertainties in bolometric corrections, obscured active black hole fractions, and kinetic accretion efficiency. For our fiducial assumptions, they favour moderate-to-rapid spins of typical supermassive black holes, to achieve ε ∼ 0.12–0.20. Our approach has similarities to the classic Soltan analysis, but by using galaxy-based data instead of integrated quantities we are able to focus on regimes where observational uncertainties are minimized.

Download Full-text

Tracing black hole and galaxy co-evolution in the Romulus simulations

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stz2161 ◽

2019 ◽

Vol 489 (1) ◽

pp. 802-819 ◽

Cited By ~ 7

Author(s):

Angelo Ricarte ◽

Michael Tremmel ◽

Priyamvada Natarajan ◽

Thomas Quinn

Keyword(s):

Black Hole ◽

Star Formation ◽

Star Formation Rate ◽

Accretion Rate ◽

Formation Rate ◽

Star Forming ◽

Black Hole Accretion ◽

Black Hole Growth ◽

Hole Growth ◽

Hole Accretion

ABSTRACT We study the link between supermassive black hole growth and the stellar mass assembly of their host galaxies in the state-of-the-art Romulus suite of simulations. The cosmological simulations Romulus25 and RomulusC employ innovative recipes for the seeding, accretion, and dynamics of black holes in the field and cluster environments, respectively. We find that the black hole accretion rate traces the star formation rate among star-forming galaxies. This result holds for stellar masses between 108 and 1012 solar masses, with a very weak dependence on host halo mass or redshift. The inferred relation between accretion rate and star formation rate does not appear to depend on environment, as no difference is seen in the cluster/proto-cluster volume compared to the field. A model including the star formation rate, the black hole-to-stellar mass ratio, and the cold gas fraction can explain about 70 per cent of all variations in the black hole accretion rate among star-forming galaxies. Finally, bearing in mind the limited volume and resolution of these cosmological simulations, we find no evidence for a connection between black hole growth and galaxy mergers, on any time-scale and at any redshift. Black holes and their galaxies assemble in tandem in these simulations, regardless of the larger scale intergalactic environment, suggesting that black hole growth simply follows star formation on galactic scales.

Download Full-text

EVOLUTION OF PRIMORDIAL BLACK HOLE MASS SPECTRUM IN BRANS–DICKE THEORY

International Journal of Modern Physics D ◽

10.1142/s0218271813500223 ◽

2013 ◽

Vol 22 (05) ◽

pp. 1350022 ◽

Cited By ~ 3

Author(s):

D. DWIVEDEE ◽

B. NAYAK ◽

L. P. SINGH

Keyword(s):

Black Holes ◽

Black Hole ◽

Mass Spectrum ◽

Energy Density ◽

Analytic Solutions ◽

Primordial Black Hole ◽

Primordial Black Holes ◽

Black Hole Mass ◽

Linear And Nonlinear ◽

The Universe

We investigate the evolution of primordial black hole mass spectrum by including both accretion of radiation and Hawking evaporation within Brans–Dicke (BD) cosmology in radiation-, matter- and vacuum-dominated eras. We also consider the effect of evaporation of primordial black holes on the expansion dynamics of the universe. The analytic solutions describing the energy density of the black holes in equilibrium with radiation are presented. We demonstrate that these solutions act as attractors for the system ensuring stability for both linear and nonlinear situations. We show, however, that inclusion of accretion of radiation delays the onset of this equilibrium in all radiation-, matter- and vacuum-dominated eras.

Download Full-text

ACCRETION MECHANISMS ONTO PRIMORDIAL BLACK HOLES

International Journal of Modern Physics D ◽

10.1142/s0218271810017433 ◽

2010 ◽

Vol 19 (08n10) ◽

pp. 1249-1252

Author(s):

D. C. GUARIENTO ◽

J. E. HORVATH

Keyword(s):

Black Holes ◽

Black Hole ◽

Dark Energy ◽

Perfect Fluid ◽

Test Fluid ◽

Primordial Black Hole ◽

Primordial Black Holes ◽

Accretion Model ◽

Hawking Evaporation

We study the evolution of a primordial black hole (PBH) taking into account the presence of dark energy modeled by a general perfect fluid. In the specific case of a stationary non-self-gravitating test fluid, the competition between radiation accretion, Hawking evaporation and the accretion of such a fluid has been studied in detail. The evaporation of PBHs is quite modified at late times by these effects. We address further generalizations of this scenario to consider other types of fluids, and point out early developments of a nonstationary accretion model.

Download Full-text

X-ray reflection spectroscopy with Kaluza–Klein black holes

The European Physical Journal C ◽

10.1140/epjc/s10052-020-8198-x ◽

2020 ◽

Vol 80 (7) ◽

Cited By ~ 3

Author(s):

Jiachen Zhu ◽

Askar B. Abdikamalov ◽

Dimitry Ayzenberg ◽

Mustapha Azreg-Aïnou ◽

Cosimo Bambi ◽

...

Keyword(s):

Black Holes ◽

Black Hole ◽

Alternative Theory ◽

Disk System ◽

X Ray ◽

Black Hole Accretion ◽

Klein Theory ◽

Black Hole Accretion Disk ◽

Hole Accretion ◽

Kaluza Klein

Abstract Kaluza–Klein theory is a popular alternative theory of gravity, with both non-rotating and rotating black hole solutions known. This allows for the possibility that the theory could be observationally tested. We present a model which calculates the reflection spectrum of a black hole accretion disk system, where the black hole is described by a rotating solution of the Kaluza–Klein theory. We also use this model to analyze X-ray data from the stella-mass black hole in GRS 1915+105 and provide constraints on the free parameters of the Kaluza–Klein black holes.

Download Full-text