A gas model for multicomponent star clusters: method and comparison with Fokker–Planck theory

Bettwieser, E.; Inagaki, Shogo

doi:10.1093/mnras/213.3.473

Cited by 15 publications

(23 citation statements)

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“…However, there are serious disagreements between those of Bettwieser et at (Bettwieser & Sugimoto 1984, Bettwieser & Fritze 1984 and the present author.…”

Section: Gaseous Modelscontrasting

confidence: 55%

Dynamical Evolution of Globular Clusters After Core Collapse

Heggie¹

1985

Symp. - Int. Astron. Union

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This review describes work on the evolution of a stellar system during the phase which starts at the end of core collapse. It begins with an account of the models of He*non, Goodman, and Inagaki and Lynden-Bell, as well as evaporative models,and modific ations to these models which are needed in the core.Next, these models are related to more detailed numerical calculations of gaseous models, Fokker-Planck models, N-body calculations, etc., and some problems for further work in these directions are outlined.The review concludes with a discussion of the relation between theoretical models and observations of the surface density profiles and statistics of actual globular clusters.

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“…However, there are serious disagreements between those of Bettwieser et at (Bettwieser & Sugimoto 1984, Bettwieser & Fritze 1984 and the present author.…”

Section: Gaseous Modelscontrasting

confidence: 55%

Dynamical Evolution of Globular Clusters After Core Collapse

Heggie¹

1985

Symp. - Int. Astron. Union

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“…Bettwieser & Inagaki (1985) give a good insight of the hydrodynamical spirit of the model but note that their closure equation requires modification for agreement with Fokker–Planck models (Spurzem & Takahashi 1995). A complete and anisotropic formulation based on moments of the Boltzmann equation can be found in Louis & Spurzem (1991).…”

Section: Methodsmentioning

confidence: 99%

“…The only free parameter in the equations of the gaseous model is the value of the conductivity (sometimes denoted λ). It is then adjusted to be consistent with N ‐body calculations and to recover the core collapse time in the case of a system of N identical masses (Bettwieser & Inagaki 1985; ; see also Spurzem 1992). Several tests have been conducted to compare gas cluster models with Fokker–Planck integrations and direct N ‐body calculations (Giersz & Heggie 1994; Giersz & Spurzem 1994; Spurzem & Takahashi 1995).…”

Section: Methodsmentioning

confidence: 99%

On the mass of dense star clusters in starburst galaxies from spectrophotometry

Fleck

Boily

Lançon

et al. 2006

Monthly Notices of the Royal Astronomical Society

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The mass of unresolved young star clusters derived from spectrophotometric data may well be off by a factor of 2 or more once the migration of massive stars driven by mass segregation is accounted for. We quantify this effect for a large set of cluster parameters, including variations in the stellar initial mass function (IMF), the intrinsic cluster mass, and mean mass density. Gas‐dynamical models coupled with the Cambridge stellar evolution tracks allow us to derive a scheme to recover the real cluster mass given measured half‐light radius, one‐dimensional velocity dispersion and age. We monitor the evolution with time of the ratio of real to apparent mass through the parameter η. When we compute η for rich star clusters, we find non‐monotonic evolution in time when the IMF stretches beyond a critical cut‐off mass of 25.5 M⊙. We also monitor the rise of colour gradients between the inner and outer volume of clusters: we find trends in time of the stellar IMF power indices overlapping well with those derived for the Large Magellanic Cloud cluster NGC 1818 at an age of 30 Myr. We argue that the core region of massive Antennae clusters should have suffered from much segregation despite their low ages. We apply these results to a cluster mass function, and find that the peak of the mass distribution would appear to observers shifted to lower masses by as much as 0.2 dex. The star formation rate derived for the cluster population is then underestimated by from 20 to 50 per cent.

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“…In each entropy equation there will be, in addition to the selfinteraction heat conduction term, pairwise thermal coupling terms to all the other components. These terms are each proportional to the difference in the local temperatures of the components and conduct heat from hotter to colder members (see, e.g., [4]). The effect of these coupling terms is to drive the system to equipartition, which in turn leads to mass segregation.…”

Section: Newtonian Treatmentmentioning

confidence: 99%

“…The fluid conduction approximation has been adopted successfully to study the dynamical evolution of a spherical star cluster, (see, e.g., [1][2][3][4][5][6][7][8]) as well as a selfinteracting dark matter (SIDM) halo (see, e.g. [7][8][9]).…”

Section: Introductionmentioning

confidence: 99%

Star clusters, self-interacting dark matter halos, and black hole cusps: The fluid conduction model and its extension to general relativity

Shapiro

2018

Phys. Rev. D

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We adopt the fluid conduction approximation to study the evolution of spherical star clusters and self-interacting dark matter (SIDM) halos. We also explore the formation and dynamical impact of density cusps that arise in both systems due to the presence of a massive, central black hole. The large N-body, self-gravitating systems we treat are "weakly-collisional": the mean free time between star or SIDM particle collisions is much longer than their characteristic crossing (dynamical) time scale, but shorter than the system lifetime. The fluid conduction model reliably tracks the "gravothermal catastrophe" in star clusters and SIDM halos without black holes. For a star cluster with a massive, central black hole, this approximation reproduces the familiar Bahcall-Wolf quasistatic density cusp for the stars bound to the black hole and shows how the cusp halts the "gravothermal catastrophe" and causes the cluster to re-expand. An SIDM halo with an initial black hole central density spike that matches onto to an exterior NFW profile relaxes to a corehalo structure with a central density cusp determined by the velocity dependence of the SIDM interaction cross section. The success and relative simplicity of the fluid conduction approach in evolving such "weakly-collisional", quasiequilibrium Newtonian systems motivates its extension to relativistic systems. We present a general relativistic extension here. PACS numbers: 95.35.+d, 98.62.Js, 98.

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A gas model for multicomponent star clusters: method and comparison with Fokker–Planck theory

Cited by 15 publications

References 0 publications

Dynamical Evolution of Globular Clusters After Core Collapse

Dynamical Evolution of Globular Clusters After Core Collapse

On the mass of dense star clusters in starburst galaxies from spectrophotometry

Star clusters, self-interacting dark matter halos, and black hole cusps: The fluid conduction model and its extension to general relativity

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