scholarly journals Dynamical evolution of rotating globular clusters with embedded black holes

2006 ◽  
Vol 2 (S238) ◽  
pp. 363-364 ◽  
Author(s):  
José Fiestas ◽  
Rainer Spurzem
Keyword(s):  
Black Holes ◽  
Angular Momentum ◽  
Globular Clusters ◽  
Structural Parameters ◽  
Dynamical Evolution ◽  
Meridional Plane ◽  
Angular Momentum Transport ◽  
Dimensional Distribution ◽  
Velocity Diffusion ◽  
Parent Galaxy

AbstractEvolution of rotating globular clusters with embedded black holes is presented. The interplay between velocity diffusion due to relaxation and black hole star accretion is followed together with cluster rotation, using 2-dimensional, in energy and z-component of angular momentum, Fokker Planck numerical methods. Gravogyro and gravothermal instabilities drive the system to a faster evolution leading to shorter collapse times and a faster cluster dissolution in the tidal field of a parent galaxy.Angular momentum transport and star accretion support the development of central rotation in relaxation time scales. Two-dimensional distribution (in the meridional plane) of kinematical and structural parameters (density, dispersions, rotation) are reproduced, with the aim to enable the use of set of models for comparison with observational data.

scholarly journals Dynamical Evolution of Rotating Globular Clusters with Embedded Black Holes

2007 ◽  
Vol 3 (S246) ◽  
pp. 166-170
Author(s):  
J. Fiestas ◽  
O. Porth ◽  
R. Spurzem
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Globular Clusters ◽  
Dynamical Evolution ◽  
Momentum Transport ◽  
Stellar Systems ◽  
Angular Momentum Transport ◽  
Zone Of Influence ◽  
Velocity Diffusion ◽  
Parent Galaxy

AbstractEvolution of self-gravitating rotating dense stellar systems (e.g. globular clusters) with embedded black holes is investigated. The interplay between velocity diffusion due to relaxation and black hole star accretion is followed together with cluster differential rotation using 2D+1 Fokker Planck numerical methods. The models can reproduce the Bahcall-Wolf f ∝ E1/4 (∝ r−7/4) cusp inside the zone of influence of the black hole. Angular momentum transport and star accretion processes support the development of central rotation in relaxation time scales, before re-expansion and cluster dissolution due to mass loss in the tidal field of a parent galaxy. Gravogyro and gravothermal instabilities conduce the system to a faster evolution leading to shorter collapse times with respect to models without black hole.

scholarly journals Dynamical Evolution of Rotating Globular Clusters

1996 ◽  
Vol 174 ◽  
pp. 375-376
Author(s):  
P.-Y. Longaretti ◽  
C. Lagoute
Keyword(s):  
Angular Momentum ◽  
Stellar Evolution ◽  
Globular Cluster ◽  
Globular Clusters ◽  
Dynamical Evolution

We have computed simplified globular cluster evolutionary tracks which take into account the effects of internal relaxation, of the cluster rotation, of the galactic tidal field, and, in a cruder way, of stellar evolution and of gravitational shocking. The objectives are first to quantify the influence of rotation in the dynamical evolution of globular clusters; and second, to investigate the evolution of globular cluster angular momentum and flattening (Lagoute and Longaretti 1995a, Longaretti and Lagoute 1995b,c).

scholarly journals Angular momentum transport in accretion disks: a hydrodynamical perspective

2019 ◽  
Vol 82 ◽  
pp. 391-413 ◽  
Author(s):  
S. Fromang ◽  
G. Lesur
Keyword(s):  
Angular Momentum ◽  
Accretion Disk ◽  
Accretion Disks ◽  
Dynamical Evolution ◽  
Theoretical Work ◽  
Momentum Transport ◽  
Angular Momentum Transport ◽  
Recent Developments ◽  
The Many ◽  
The Universe

The radial transport of angular momentum in accretion disk is a fundamental process in the universe. It governs the dynamical evolution of accretion disks and has implications for various issues ranging from the formation of planets to the growth of supermassive black holes. While the importance of magnetic fields for this problem has long been demonstrated, the existence of a source of transport solely hydrodynamical in nature has proven more difficult to establish and to quantify. In recent years, a combination of results coming from experiments, theoretical work and numerical simulations has dramatically improved our understanding of hydrodynamically mediated angular momentum transport in accretion disk. Here, based on these recent developments, we review the hydrodynamical processes that might contribute to transporting angular momentum radially in accretion disks and highlight the many questions that are still to be answered.

scholarly journals Stellar-mass Black Holes in Globular Clusters: Dynamical consequences and observational signatures

2019 ◽  
Vol 14 (S351) ◽  
pp. 395-399 ◽  
Author(s):  
Abbas Askar ◽  
Mirek Giersz ◽  
Manuel Arca Sedda ◽  
Ammar Askar ◽  
Mario Pasquato ◽  
...  
Keyword(s):  
Black Holes ◽  
Globular Clusters ◽  
Dynamical Evolution ◽  
Stellar Mass ◽  
Large Set ◽  
Term Survival ◽  
Central Surface ◽  
Sizeable Number ◽  
Hubble Time

AbstractSizeable number of stellar-mass black holes (BHs) in globular clusters (GCs) can strongly influence the dynamical evolution and observational properties of their host cluster. Using results from a large set of numerical simulations, we identify the key ingredients needed to sustain a sizeable population of BHs in GCs up to a Hubble time. We find that while BH natal kick prescriptions are essential in determining the initial retention fraction of BHs in GCs, the long-term survival of BHs is determined by the size, initial central density and half-mass relaxation time of the GC. Simulated GC models that contain many BHs are characterized by relatively low central surface brightness, large half-light and core radii values. We also discuss novel ways to compare simulated results with available observational data to identify GCs that are most likely to contain many BHs.

scholarly journals Nuclear angular momentum of early-type galaxies hosting nuclear star clusters

2019 ◽  
Vol 629 ◽  
pp. A44 ◽  
Author(s):  
Mariya Lyubenova ◽  
Athanassia Tsatsi
Keyword(s):  
Black Holes ◽  
Angular Momentum ◽  
Adaptive Optics ◽  
Globular Clusters ◽  
Milky Way ◽  
Star Clusters ◽  
Galactic Nuclei ◽  
Host Galaxy ◽  
Early Type ◽  
Stellar Kinematics

Context. Nucleation is a common phenomenon in all types of galaxies and at least 70% of them host nuclear star clusters (NSCs) in their centres. Many of the NSCs co-habit with supermassive black holes and follow similar scaling relations with host galaxy properties. Unlike black holes, NSCs, preserve the signature of their evolutionary path imprinted onto their kinematics and stellar populations. Thus their study provides us with important information about the formation of galactic nuclei. Aims. In this paper we explored the angular momentum of the nuclei of six intermediate mass (9.7 >  log(Mdyn/M⊙) > 10.6) early-type galaxies that host NSCs and are located in the Fornax cluster. Our goal was to derive a link between the nuclear angular momentum and the proposed formation scenarios of NSCs. Methods. We used adaptive optics assisted IFU observations with VLT/SINFONI to derive the spatially resolved stellar kinematics of the galaxy nuclei. We measured their specific stellar angular momenta λRe, and compared these with Milky Way globular clusters (GCs) and N-body simulations of NSC formation. Results. We found that all studied nuclei exhibit varied stellar kinematics. Their λRe and ellipticities are similar to Milky Way GCs. Five out of six galaxy nuclei are consistent with the λRe − ϵe of simulated NSCs embedded in a contaminating nuclear bulge that have formed via the in-spiralling and merging of GCs. Conclusion. It has previously been suggested that the NSCs in higher mass galaxies, such as those studied in this paper, form via dissipational sinking of gas onto the galactic nuclei with hints that some might also involve the merger of GCs. In this work we show that we cannot exclude the pure GC merging scenario as a viable path for the formation of NSCs.

scholarly journals THE DYNAMICAL EVOLUTION OF STELLAR BLACK HOLES IN GLOBULAR CLUSTERS

2015 ◽  
Vol 800 (1) ◽  
pp. 9 ◽  
Author(s):  
Meagan Morscher ◽  
Bharath Pattabiraman ◽  
Carl Rodriguez ◽  
Frederic A. Rasio ◽  
Stefan Umbreit
Keyword(s):  
Black Holes ◽  
Globular Clusters ◽  
Dynamical Evolution

scholarly journals HST's hunt for intermediate-mass black holes in star clusters

2009 ◽  
Vol 5 (S266) ◽  
pp. 231-237 ◽  
Author(s):  
Julio Chanamé ◽  
Justice Bruursema ◽  
Rupali Chandar ◽  
Jay Anderson ◽  
Roeland van der Marel ◽  
...  
Keyword(s):  
Black Holes ◽  
Globular Clusters ◽  
Star Clusters ◽  
Dynamical Evolution ◽  
Dynamical Analysis ◽  
Intermediate Mass ◽  
Data Set ◽  
Upper Limits ◽  
Intermediate Mass Black Holes

AbstractEstablishing or ruling out, either through solid mass measurements or upper limits, the presence of intermediate-mass black holes (IMBHs; with masses of 102 − 105 M⊙) at the centers of star clusters would profoundly impact our understanding of problems ranging from the formation and long-term dynamical evolution of stellar systems, to the nature of the seeds and the growth mechanisms of supermassive black holes. While there are sound theoretical arguments both for and against their presence in today's clusters, observational studies have so far not yielded truly conclusive IMBH detections nor upper limits. We argue that the most promising approach to solving this issue is provided by the combination of measurements of the proper motions of stars at the centers of Galactic globular clusters and dynamical models able to take full advantage of this type of data set. We present a program based on HST observations and recently developed tools for dynamical analysis designed to do just that.

Dynamical evolution of globular clusters: Recent developments

2017 ◽  
Vol 26 (09) ◽  
pp. 1730017
Author(s):  
Marco Merafina
Keyword(s):  
Globular Cluster ◽  
Globular Clusters ◽  
Milky Way ◽  
Structural Parameters ◽  
Dynamical Evolution ◽  
Limit Value ◽  
Tidal Forces ◽  
The Galaxy ◽  
Recent Developments ◽  
Theoretical Results

We analyze structural parameters of the globular clusters belonging to the Milky Way system which were listed in the latest edition of the Harris Catalogue. We search for observational evidences of the effect of tidal forces induced by the Galaxy on the dynamical and thermodynamical evolution of a globular cluster. The behavior for the [Formula: see text] distribution exhibited by the globular cluster population seems to be in contrast with theoretical results in literature about gravothermal instability, and suggest a new limit value smaller than the previous one.

scholarly journals MOCCA Survey Database: Extra Galactic Globular Clusters. I. Method and first results

2021 ◽  
Author(s):  
A Leveque ◽  
M Giersz ◽  
M Paolillo
Keyword(s):  
Globular Clusters ◽  
Surface Brightness ◽  
Velocity Dispersion ◽  
Structural Parameters ◽  
Dynamical Evolution ◽  
Central Surface ◽  
First Results ◽  
Preliminary Study ◽  
Galactic Globular Clusters ◽  
Gaia Dr2

Abstract Over the last few decades, exhaustive surveys of extra Galactic globular clusters (EGGCs) have become feasible. Only recently, limited kinematical information of globular clusters (GCs) were available through Gaia DR2 spectroscopy and also proper motions. On the other hand, simulations of GCs can provide detailed information about the dynamical evolution of the system. We present a preliminary study of EGGCs- properties for different dynamical evolutionary stages. We apply this study to 12 Gyr-old GCs simulated as part of the MOCCA Survey Database. Mimicking observational limits, we consider only a subssample of the models in the database, showing that it is possible to represent observed Milky Way GCs. In order to distinguish between different dynamical states of EGGCs, at least three structural parameters are necessary. The best distinction is achieved by considering the central parameters, those being observational core radius, central surface brightness, ratio between central and half-mass velocity dispersion, or similarly considering the central color, the central V magnitude and the ratio between central and half-mass radius velocity dispersion, although such properties could be prohibitive with current technologies. A similar but less solid result is obtained considering the average properties at the half-light radius, perhaps accessible presently in the Local Group. Additionally, we mention that the color spread in EGGCs due to internal dynamical models, at fixed metallcity, could be just as important due to the spread in metallicity.

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