scholarly journals Formation and Evolution of Black Holes in Galactic Nuclei and Star Clusters

2007 ◽  
Vol 3 (S246) ◽  
pp. 346-350
Author(s):  
R. Spurzem ◽  
P. Berczik ◽  
I. Berentzen ◽  
D. Merritt ◽  
M. Preto ◽  
...  
Keyword(s):  
Black Holes ◽  
Gravitational Waves ◽  
Star Clusters ◽  
Galactic Nuclei ◽  
Stellar Dynamics ◽  
Compact Objects ◽  
Binary Black Holes ◽  
Black Hole Binaries ◽  
Orbital Parameters ◽  
Work Done

AbstractWe study the formation, growth, and co-evolution of single and multiple supermassive black holes (SMBHs) and compact objects like neutron stars, white dwarfs, and stellar mass black holes in galactic nuclei and star clusters, focusing on the role of stellar dynamics. In this paper we focus on one exemplary topic out of a wider range of work done, the study of orbital parameters of binary black holes in galactic nuclei (binding energy, eccentricity, relativistic coalescence) as a function of initial parameters. In some cases the classical evolution of black hole binaries in dense stellar systems drives them to surprisingly high eccentricities, which is very exciting for the emission of gravitational waves and relativistic orbit shrinkage. Such results are interesting to the emerging field of gravitational wave astronomy, in relation to a number of ground and space based instruments designed to measure gravitational waves from astrophysical sources (VIRGO, Geo600, LIGO, LISA). Our models self-consistently cover the entire range from Newtonian dynamics to the relativistic coalescence of SMBH binaries.

scholarly journals Black hole and neutron star mergers in galactic nuclei: the role of triples

2019 ◽  
Vol 488 (2) ◽  
pp. 2825-2835 ◽  
Author(s):  
Giacomo Fragione ◽  
Nathan W C Leigh ◽  
Rosalba Perna
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Neutron Star ◽  
Massive Stars ◽  
Star Clusters ◽  
Galactic Nuclei ◽  
Compact Objects ◽  
Large Numbers ◽  
Binary Case

ABSTRACT Nuclear star clusters that surround supermassive black holes (SMBHs) in galactic nuclei are thought to contain large numbers of black holes (BHs) and neutron stars (NSs), a fraction of which form binaries and could merge by Kozai–Lidov oscillations (KL). Triple compact objects are likely to be present, given what is known about the multiplicity of massive stars, whose life ends either as an NS or a BH. In this paper, we present a new possible scenario for merging BHs and NSs in galactic nuclei. We study the evolution of a triple black hole (BH) or neutron star (NS) system orbiting an SMBH in a galactic nucleus by means of direct high-precision N-body simulations, including post-Newtonian terms. We find that the four-body dynamical interactions can increase the KL angle window for mergers compared to the binary case and make BH and NS binaries merge on shorter time-scales. We show that the merger fraction can be up to ∼5–8 times higher for triples than for binaries. Therefore, even if the triple fraction is only ∼10–$20\rm{\,per\,cent}$ of the binary fraction, they could contribute to the merger events observed by LIGO/VIRGO in comparable numbers.

scholarly journals mocca-survey Database I: Binary black hole mergers from globular clusters with intermediate mass black holes

2020 ◽  
Vol 498 (3) ◽  
pp. 4287-4294
Author(s):  
Jongsuk Hong ◽  
Abbas Askar ◽  
Mirek Giersz ◽  
Arkadiusz Hypki ◽  
Suk-Jin Yoon
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Gravitational Waves ◽  
Globular Clusters ◽  
Stellar Mass ◽  
Intermediate Mass ◽  
Binary Black Holes ◽  
Black Hole Binaries ◽  
Binary Black Hole ◽  
Intermediate Mass Black Holes

ABSTRACT The dynamical formation of black hole binaries in globular clusters that merge due to gravitational waves occurs more frequently in higher stellar density. Meanwhile, the probability to form intermediate mass black holes (IMBHs) also increases with the density. To explore the impact of the formation and growth of IMBHs on the population of stellar mass black hole binaries from globular clusters, we analyse the existing large survey of Monte Carlo globular cluster simulation data (mocca-survey Database I). We show that the number of binary black hole mergers agrees with the prediction based on clusters’ initial properties when the IMBH mass is not massive enough or the IMBH seed forms at a later time. However, binary black hole formation and subsequent merger events are significantly reduced compared to the prediction when the present-day IMBH mass is more massive than ${\sim}10^4\, \rm M_{\odot }$ or the present-day IMBH mass exceeds about 1 per cent of cluster’s initial total mass. By examining the maximum black hole mass in the system at the moment of black hole binary escaping, we find that ∼90 per cent of the merging binary black holes escape before the formation and growth of the IMBH. Furthermore, large fraction of stellar mass black holes are merged into the IMBH or escape as single black holes from globular clusters in cases of massive IMBHs, which can lead to the significant underpopulation of binary black holes merging with gravitational waves by a factor of 2 depending on the clusters’ initial distributions.

GRAVITATIONAL THERMODYNAMICS AND BLACK-HOLE MERGERS

2000 ◽  
Vol 15 (30) ◽  
pp. 4871-4875 ◽  
Author(s):  
SIMON F. PORTEGIES ZWART ◽  
STEPHEN L. W. MCMILLAN
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Neutron Star ◽  
Gravitational Waves ◽  
Star Clusters ◽  
Black Hole Binaries ◽  
Orbital Periods ◽  
Binary Evolution ◽  
Event Rates ◽  
Gravitational Thermodynamics

Black holes become the most massive objects early in the evolution of star clusters. Dynamical relaxation then causes them to sink to the cluster core, where they form binaries which become more tightly bound by superelastic encounters with other cluster members. Ultimately, these binaries are ejected from the cluster. The majority of escaping black-hole binaries have orbital periods short enough and eccentricities high enough that the emission of gravitational waves causes them to coalesce within a few billion years. The rate at which such collisions occur is on the order of 10-7 per year per cubic megaparsec. This implies event rates for gravitational-wave detectors substantially greater than current estimates of the corresponding rates from neutron-star mergers or black-hole mergers stemming from pure binary evolution.

scholarly journals Enriching the symphony of gravitational waves from binary black holes by tuning higher harmonics

2018 ◽  
Vol 98 (8) ◽  
Author(s):  
Roberto Cotesta ◽  
Alessandra Buonanno ◽  
Alejandro Bohé ◽  
Andrea Taracchini ◽  
Ian Hinder ◽  
...  
Keyword(s):  
Black Holes ◽  
Gravitational Waves ◽  
Higher Harmonics ◽  
Binary Black Holes

scholarly journals BINARY BLACK HOLES IN DENSE STAR CLUSTERS: EXPLORING THE THEORETICAL UNCERTAINTIES

2017 ◽  
Vol 834 (1) ◽  
pp. 68 ◽  
Author(s):  
Sourav Chatterjee ◽  
Carl L. Rodriguez ◽  
Frederic A. Rasio
Keyword(s):  
Black Holes ◽  
Star Clusters ◽  
Binary Black Holes

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

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.

scholarly journals Stellar dynamics of galactic nuclei with TIGER

1995 ◽  
Vol 149 ◽  
pp. 282-287 ◽  
Author(s):  
Eric Emsellem ◽  
Roland Bacon ◽  
Guy Monnet
Keyword(s):  
Black Holes ◽  
Galactic Nuclei ◽  
Stellar Dynamics ◽  
Dynamical Structure ◽  
M 31 ◽  
Dynamical Properties ◽  
Integral Field Spectrograph ◽  
Integral Field ◽  
Observational Program

AbstractWe conducted an observational program using the TIGER integral field spectrograph to study the dynamical structure of nearby galactic nuclei. We already obtained new original results on three of the best ”Black Holes Candidates”: M 32, M 31 and M 104. Their nuclei exhibit complex morphologies and unusual dynamical properties such as: asymmetries, anisotropy, triaxiality which would have been impossible to detect with a ”classical“ spectrograph.

scholarly journals The Evolutionary Evidence for Be/Black Hole Binaries

2000 ◽  
Vol 175 ◽  
pp. 689-692
Author(s):  
Natalya V. Raguzova ◽  
Vladimir M. Lipunov
Keyword(s):  
Black Holes ◽  
Binary Systems ◽  
Be Stars ◽  
Evolutionary Track ◽  
Binary Black Holes ◽  
Black Hole Binaries ◽  
Eccentric Orbits ◽  
Evolutionary Scenario ◽  
The Galaxy ◽  
Near Future

AbstractUsing a Monte Carlo simulation of the modern scenario of the evolution of binary systems (the “Scenario Machine”), we calculate the number of binary black holes with Be stars and their expected observational properties. So far, only two possible candidates for Be/BH binaries have been proposed among the observable sources, the superluminal source GRS 1915+105 in the Galaxy and RX J0117.6–7330 in the SMC. We obtained an evolutionary track that can lead to the formation of such systems. The modern evolutionary scenario predicts the existence of binary black holes on eccentric orbits around Be stars and such systems may be discovered in the near future.

scholarly journals Tests of CPT invariance in gravitational waves with LIGO-Virgo catalog GWTC-1

2020 ◽  
Vol 80 (11) ◽  
Author(s):  
Sai Wang ◽  
Zhi-Chao Zhao
Keyword(s):  
Black Holes ◽  
Dispersion Relation ◽  
Gravitational Waves ◽  
Cpt Violation ◽  
Cpt Invariance ◽  
Binary Black Holes ◽  
Better Than

AbstractA discovery of gravitational waves from binary black holes raises a possibility that measurements of them can provide strict tests of CPT invariance in gravitational waves. When CPT violation exists, if any, gravitational waves with different circular polarizations could gain a slight difference in propagating speeds. Hence, the birefringence of gravitational waves is induced and there should be a rotation of plus and cross modes. For CPT-violating dispersion relation $${\omega ^{2}=k^{2}}$$ ω 2 = k 2 $${\pm 2\zeta k^{3}}$$ ± 2 ζ k 3 , where a sign $${\pm }$$ ± denotes different circular polarizations, we find no substantial deviations from CPT invariance in gravitational waves by analyzing a compilation of ten signals of binary black holes in the LIGO-Virgo catalog GWTC-1. We obtain a strict constraint on the CPT-violating parameter, i.e., $$\zeta =0.14^{+0.22}_{-0.31}\times 10^{-15}\,\text {m}$$ ζ = 0 . 14 - 0.31 + 0.22 × 10 - 15 m , which is around two orders of magnitude better than the existing one. Therefore, this study stands for the up-to-date strictest tests of CPT invariance in gravitational waves.

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