Dynamical evolution of rotating dense stellar systems with embedded black holes

Fiestas, J.; Spurzem, Rainer

doi:10.1111/j.1365-2966.2010.16479.x

Cited by 18 publications

(24 citation statements)

References 74 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In principle, such a study can be done using an axisymmetric model which is closer to ω Centauri, as an exception in Galactic star clusters. Fiestas & Spurzem (2010) investigated the evolution of rotating dense stellar systems containing massive black holes. Exploring rotation effects could help to better understand the observed discrepancy between proper motion and radial velocity dispersion.…”

Section: Discussionmentioning

confidence: 99%

A DynamicalN-body model for the central region ofωCentauri

Jalali

Baumgardt

Kissler-Patig

et al. 2012

A&A

View full text Add to dashboard Cite

Context. Supermassive black holes (SMBHs) are fundamental keys to understand the formation and evolution of their host galaxies. However, the formation and growth of SMBHs are not yet well understood. One of the proposed formation scenarios is the growth of SMBHs from seed intermediate-mass black holes (IMBHs, 10 2 to 10 5 M ) formed in star clusters. In this context, and also with respect to the low mass end of the M • − σ relation for galaxies, globular clusters are in a mass range that make them ideal systems to look for IMBHs. Among Galactic star clusters, the massive cluster ω Centauri is a special target due to its central high velocity dispersion and also its multiple stellar populations. Aims. We study the central structure and dynamics of the star cluster ω Centauri to examine whether an IMBH is necessary to explain the observed velocity dispersion and surface brightness profiles. Methods. We perform direct N-body simulations on GPU and GRAPE special purpose computers to follow the dynamical evolution of ω Centauri. The simulations are compared to the most recent data-sets in order to explain the present-day conditions of the cluster and to constrain the initial conditions leading to the observed profiles. Results. We find that starting from isotropic spherical multi-mass King models and within our canonical assumptions, a model with a central IMBH mass of 2% of the cluster stellar mass, i.e. a 5. × 10 4 M IMBH, provides a satisfactory fit to both the observed shallow cusp in surface brightness and the continuous rise towards the center of the radial velocity dispersion profile. In our isotropic spherical models, the predicted proper motion dispersion for the best-fit model is the same as the radial velocity dispersion one. Conclusions. We conclude that with the presence of a central IMBH in our models, we reproduce consistently the rise in the radial velocity dispersion. Furthermore, we always end up with a shallow cusp in the projected surface brightness of our model clusters containing an IMBH. In addition, we find that the M/L ratio seems to be constant in the central region, and starts to rise slightly from the core radius outwards for all models independent of the presence of a black hole. Considering our initial parameter space, it is not possible to explain the observations without a central IMBH for ω Centauri. To further strengthen the presence of an IMBH as a unique explanation of the observed light and kinematics more detailed analysis such as investigating the contribution of primordial binaries and different anisotropy profiles should be studied.

show abstract

Section: Discussionmentioning

confidence: 99%

A DynamicalN-body model for the central region ofωCentauri

Jalali

Baumgardt

Kissler-Patig

et al. 2012

A&A

View full text Add to dashboard Cite

show abstract

“…All of the simulations have been done with these varying parameters, and physical conclusions are drawn from extrapolating to the real galactic conditions. Fiestas & Spurzem (2010) have shown in Fokker-Planck models that such scaling is reliable and provides physically correct results. Besides, tidal disruption events in our simulations, as well as the case in the real galactic center, do not occur frequently, which means that the increase of M BH is discrete.…”

Section: Calculate Tidal Disruption Rate Numericallymentioning

confidence: 99%

Interaction of Recoiling Supermassive Black Holes With Stars in Galactic Nuclei

Liu

Berczik

et al. 2012

ApJ

View full text Add to dashboard Cite

Supermassive black hole binaries (SMBHBs) are the products of frequent galaxy mergers. The coalescence of the SMBHBs is a distinct source of gravitational wave (GW) radiation. The detections of the strong GW radiation and their possible electromagnetic counterparts are essential. Numerical relativity suggests that the post-merger supermassive black hole (SMBH) gets a kick velocity up to 4000 km s −1 due to the anisotropic GW radiations. Here, we investigate the dynamical coevolution and interaction of the recoiling SMBHs and their galactic stellar environments with one million direct N-body simulations including the stellar tidal disruption by the recoiling SMBHs. Our results show that the accretion of disrupted stars does not significantly affect the SMBH dynamical evolution. We investigate the stellar tidal disruption rates as a function of the dynamical evolution of oscillating SMBHs in the galactic nuclei. Our simulations show that most stellar tidal disruptions are contributed by the unbound stars and occur when the oscillating SMBHs pass through the galactic center. The averaged disruption rate is ∼10 −6 M yr −1 , which is about an order of magnitude lower than that by a stationary SMBH at similar galactic nuclei. Our results also show that a bound star cluster is around the oscillating SMBH of about ∼0.7% the black hole mass. In addition, we discover a massive cloud of unbound stars following the oscillating SMBH. We also investigate the dependence of the results on the SMBH masses and density slopes of the galactic nuclei.

show abstract

“…Many such studies have been conducted over the years (see e.g. Cohn 1979;Watanabe et al 1981;Nishida et al 1984;Yepes & Domínguez-Tenreiro 1992;Takahashi 1995;Theuns 1996;Takahashi et al 1997;Joshi et al 2001;Ashurov 2004;Fiestas & Spurzem 2010). Owing to the nature of the problem, the equations are usually solved numerically with approximative methods such as Monte Carlo (statistics) and moment equations (averages).…”

Section: Introductionmentioning

confidence: 99%

Numerical self-consistent distribution function of flattened ring models

Alarcón

Calister

Ujevic

2014

A&A

View full text Add to dashboard Cite

We provide numerical, self-consistent distribution functions for several flat ring models by simultaneously solving the Fokker-Planck equation and the Poisson equation. In particular, we calculated the distribution function of flat ring systems formed by superposing Kuzmin-Toomre disc solutions and an analytic homogeneous ring solution in terms of complete elliptic integrals. We used these geometrical disc solutions, together with physical parameters, to model more realistic physical systems. Moreover, we defined a cutoff radius to handle the infinite Kuzmin-Toomre disc families numerically. The Fokker-Planck equation is solved by a direct numerical method using the finite difference method, the left conjugate direction algorithm, and a simple boundary condition that allows us to find good results for a large set of physical parameters and for values of the collision term of the same order of magnitude (or larger) when compared with the other terms in the Fokker-Planck equation. The collision term of the Fokker-Planck equation is explicitly calculated by applying the known Rosenbluth potentials for gravitational encounters. Limitations of the method are also discussed.

show abstract

Dynamical evolution of rotating dense stellar systems with embedded black holes

Cited by 18 publications

References 74 publications

A DynamicalN-body model for the central region ofωCentauri

A DynamicalN-body model for the central region ofωCentauri

Interaction of Recoiling Supermassive Black Holes With Stars in Galactic Nuclei

Numerical self-consistent distribution function of flattened ring models

Contact Info

Product

Resources

About