Erratum: Binary black hole mergers from globular clusters: the impact of globular cluster properties

AbstractThe globular cluster ω Centauri is one of the largest and most massive members of the Galactic system. Its classification as a globular cluster has been challenged making it a candidate for being the stripped core of an accreted dwarf galaxy; this and the fact that it has one of the largest velocity dispersions for star clusters in our galaxy makes it an interesting candidate for harboring an intermediate mass black hole. We measure the surface brightness profile from integrated light on an HST/ACS image, and find a central power-law cusp of logarithmic slope -0.08. We also analyze Gemini GMOS-IFU kinematic data for a 5”x5” field centered on the nucleus of the cluster, as well as for a field 14″ away. We detect a clear rise in the velocity dispersion from 18.6 kms−1 at 14″ to 23 kms−1 in the center. Given the very large core in ω Cen (2.58'), an increase in the dispersion in the central 10″ is difficult to attribute to stellar remnants, since it requires too many dark remnants and the implied configuration would dissolve quickly given the relaxation time in the core. However, the increase could be consistent with the existence of a central black hole. Assuming a constant M/L for the stars within the core, the dispersion profile from these data and data at larger radii implies a black hole mass of 4.0+0.75−1.0×104M⊙. We have also run flattened, orbit-based models and find a similar mass. In addition, the no black hole case for the orbit model requires an extreme amount of radial anisotropy, which is difficult to preserve given the short relaxation time of the cluster.

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The eye of Gaia on globular cluster kinematics: Internal rotation

Proceedings of the International Astronomical Union ◽

10.1017/s1743921319007099 ◽

2019 ◽

Vol 14 (S351) ◽

pp. 516-519

Author(s):

A. Sollima ◽

H. Baumgardt ◽

M. Hilker

Keyword(s):

Internal Rotation ◽

Globular Cluster ◽

Globular Clusters ◽

Stellar Systems ◽

Large Sample ◽

Data Release ◽

Extensive Collection ◽

Formation And Evolution ◽

The Impact ◽

Insight Into

AbstractI present the results of a survey of the kinematics of a large sample of Galactic globular clusters performed thanks to the synergy between the 2nd Gaia data release and the most extensive collection of radial velocities. This unprecedented dataset of 3D velocities of thousand of stars in 62 globular clusters has been used to investigate the rotation patterns of these stellar systems providing insight into the impact of two-body relaxation and tides on the formation and evolution of their rotation.

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Population synthesis of black hole binary mergers from star clusters

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stz3584 ◽

2020 ◽

Vol 492 (2) ◽

pp. 2936-2954 ◽

Cited By ~ 13

Author(s):

Fabio Antonini ◽

Mark Gieles

Keyword(s):

Black Hole ◽

Globular Clusters ◽

Initial Conditions ◽

Star Clusters ◽

Population Synthesis ◽

Wide Range ◽

Binary Mergers ◽

Cluster Properties ◽

Black Hole Binary ◽

Merger Rate

ABSTRACT Black hole (BH) binary mergers formed through dynamical interactions in dense star clusters are believed to be one of the main sources of gravitational waves (GWs) for Advanced LIGO and Virgo. Here, we present a fast numerical method for simulating the evolution of star clusters with BHs, including a model for the dynamical formation and merger of BH binaries. Our method is based on Hénon’s principle of balanced evolution, according to which the flow of energy within a cluster must be balanced by the energy production inside its core. Because the heat production in the core is powered by the BHs, one can then link the evolution of the cluster to the evolution of its BH population. This allows us to construct evolutionary tracks of the cluster properties including its BH population and its effect on the cluster and, at the same time, determine the merger rate of BH binaries as well as their eccentricity distributions. The model is publicly available and includes the effects of a BH mass spectrum, mass-loss due to stellar evolution, the ejection of BHs due to natal and dynamical kicks, and relativistic corrections during binary–single encounters. We validate our method using direct N-body simulations, and find it to be in excellent agreement with results from recent Monte Carlo models of globular clusters. This establishes our new method as a robust tool for the study of BH dynamics in star clusters and the modelling of GW sources produced in these systems. Finally, we compute the rate and eccentricity distributions of merging BH binaries for a wide range of cluster initial conditions, spanning more than two orders of magnitude in mass and radius.

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Erratum: Binary Black Hole Mergers from Globular Clusters: Implications for Advanced LIGO [Phys. Rev. Lett.115, 051101 (2015)]

Physical Review Letters ◽

10.1103/physrevlett.116.029901 ◽

2016 ◽

Vol 116 (2) ◽

Cited By ~ 15

Author(s):

Carl L. Rodriguez ◽

Meagan Morscher ◽

Bharath Pattabiraman ◽

Sourav Chatterjee ◽

Carl-Johan Haster ◽

...

Keyword(s):

Black Hole ◽

Globular Clusters ◽

Binary Black Hole

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The Impact of Pair-instability Mass Loss on the Binary Black Hole Mass Distribution

The Astrophysical Journal ◽

10.3847/1538-4357/ab3981 ◽

2019 ◽

Vol 882 (2) ◽

pp. 121 ◽

Cited By ~ 27

Author(s):

Simon Stevenson ◽

Matthew Sampson ◽

Jade Powell ◽

Alejandro Vigna-Gómez ◽

Coenraad J. Neijssel ◽

...

Keyword(s):

Black Hole ◽

Mass Loss ◽

Mass Distribution ◽

Black Hole Mass ◽

Binary Black Hole ◽

The Impact

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

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa2677 ◽

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.

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Searching for eccentricity: signatures of dynamical formation in the first gravitational-wave transient catalogue of LIGO and Virgo

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stz2996 ◽

2019 ◽

Vol 490 (4) ◽

pp. 5210-5216 ◽

Cited By ~ 19

Author(s):

Isobel M Romero-Shaw ◽

Paul D Lasky ◽

Eric Thrane

Keyword(s):

Black Holes ◽

Black Hole ◽

Bayesian Inference ◽

Gravitational Wave ◽

Globular Clusters ◽

Reference Frequency ◽

Binary Black Holes ◽

Binary Black Hole ◽

Upper Limits ◽

Formation History

ABSTRACT Binary black holes are thought to form primarily via two channels: isolated evolution and dynamical formation. The component masses, spins, and eccentricity of a binary black hole system provide clues to its formation history. We focus on eccentricity, which can be a signature of dynamical formation. Employing the spin-aligned eccentric waveform model seobnre, we perform Bayesian inference to measure the eccentricity of binary black hole merger events in the first gravitational-wave transient catalogue of LIGO and Virgo. We find that all of these events are consistent with zero eccentricity. We set upper limits on eccentricity ranging from 0.02 to 0.05 with 90 per cent confidence at a reference frequency of $10\, {\rm Hz}$. These upper limits do not significantly constrain the fraction of LIGO–Virgo events formed dynamically in globular clusters, because only $\sim 5{{\ \rm per\ cent}}$ are expected to merge with measurable eccentricity. However, with the gravitational-wave transient catalogue set to expand dramatically over the coming months, it may soon be possible to significantly constrain the fraction of mergers taking place in globular clusters using eccentricity measurements.

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