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Related papers: A Semi-Analytic dynamical friction model that repr…

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In order to understand the collapse dynamics of observed low-mass starless cores, we revise the conventional stability condition of hydrostatic Bonnor-Ebert spheres to take internal motions into account. Because observed starless cores…

Astrophysics of Galaxies · Physics 2015-06-15 Young Min Seo , Seung Soo Hong , Yancy L. Shirley

We present an improved semi-analytical model to predict density profiles of self-interacting dark matter (SIDM) halos and apply it to constrain the self-scattering cross section using SPARC galaxy rotation curves. Building on the isothermal…

Astrophysics of Galaxies · Physics 2026-01-27 Zixiang Jia , Fangzhou Jiang , Shubo Li , Ran Li , Jing Wang , Ling Zhu

A collisional $N$-body simulation using NBODY5 on a single CRAY YMP processor is followed well into the post-collapse regime. This is presently one of the largest particle numbers of all such models published, but some data for an even…

Astrophysics · Physics 2015-06-24 Rainer Spurzem , Sverre J. Aarseth

We introduce a dual-core system with double symmetry, one between the cores, and one along each core, imposed by the spatial modulation of local nonlinearity in the form of two tightly localized spots, which may be approximated by a pair of…

Pattern Formation and Solitons · Physics 2018-05-15 Krzysztof B. Zegadlo , Nguyen Viet Hung , Aleksandr Ramaniuk , Marek Trippenbach , Boris A. Malomed

Core collapse, a process associated with self-interacting dark matter (SIDM) models, can increase the central density of halos by orders of magnitude with observable consequences for dwarf galaxy properties and gravitational lensing.…

Astrophysics of Galaxies · Physics 2025-10-06 Vinh Tran , Xuejian Shen , Daniel Gilman , Mark Vogelsberger , Stephanie O'Neil , Donghua Xiong , Jiayi Hu , Ziang Wu

Current theories of dynamical friction on galactic bars are based either on linear perturbation theory, which is valid only in the fast limit where the bar changes its pattern speed rapidly, or on adiabatic theory, which is applicable only…

Astrophysics of Galaxies · Physics 2023-08-04 Rimpei Chiba

We present 3D kinematic observations of stars within the central 0.5 pc of the Milky Way nuclear star cluster using adaptive optics imaging and spectroscopy from the Keck telescopes. Recent observations have shown that the cluster has a…

Astrophysics of Galaxies · Physics 2015-06-17 T. Do , G. D. Martinez , S. Yelda , A. M. Ghez , J. Bullock , M. Kaplinghat , J. R. Lu , A. G. H. Peter , K. Phifer

We present a novel analytic density profile for halos in self-interacting dark matter (SIDM) models, which accurately captures the isothermal-core configuration, i.e. where both the density and velocity dispersion profiles exhibit central…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-13 Vinh Tran , Xuejian Shen , Mark Vogelsberger , Daniel Gilman , Stephanie O'Neil , Cian Roche , Oliver Zier , Jiarun Gao

Distinguishing a core and a cusp within dark matter halos is complexified by the existence of mass-anisotropy degeneracy, where various combinations of velocity anisotropy ($\beta$) and inner density slope ($\gamma$) yield similar…

Astrophysics of Galaxies · Physics 2025-02-21 Dafa Wardana , Masashi Chiba , Kohei Hayashi

We present a numerical study, based on Monte Carlo simulations, aimed at defining new empirical parameters measurable from observations and able to trace the different phases of star cluster dynamical evolution. As expected, a central…

Astrophysics of Galaxies · Physics 2022-02-23 B. Bhat , B. Lanzoni , F. R. Ferraro , E. Vesperini

We extend the classical formulation of the dynamical friction effect on a test star by Chandrasekhar to the case of relativistic velocities and velocity distributions also accounting for post-Newtonian corrections to the gravitational…

Astrophysics of Galaxies · Physics 2023-09-27 Caterina Chiari , Pierfrancesco Di Cintio

Important physical observations in rupture dynamics such as static fault friction, short-slip, self-healing, and supershear phenomenon in cracks are studied. A continuum model of rupture dynamics is developed using the field dislocation…

Materials Science · Physics 2023-12-18 Abhishek Arora , Amit Acharya

It is well known that the simple criterion proposed originally by Polyachenko and Shukhman (1981) for the onset of the radial orbit instability, although being generally a useful tool, faces significant exceptions both on the side of mildly…

Astrophysics · Physics 2016-08-30 M. Trenti , G. Bertin

Dynamical friction implies a consistency check on any system where dark matter particles are hypothesised to explain orbital dynamics requiring more mass under Newtonian gravity than is directly detectable. Introducing the assumption of a…

Astrophysics of Galaxies · Physics 2025-11-07 X. Hernandez , Pavel Kroupa

One of the hottest questions in the cosmology of self-interacting dark matter (SIDM) is whether scatterings can induce detectable core-collapse in halos by the present day. Because gravitational tides can accelerate core-collapse, the most…

We devise a method to constrain self-interacting dark matter (SIDM) from observations of quadruply-imaged quasars, and apply it to five self-interaction potentials with a long-range dark force. We consider several SIDM models with an…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-17 Daniel Gilman , Yi-Ming Zhong , Jo Bovy

Self-interacting dark matter (SIDM) theory predicts that dark matter halos experience core-collapse, a process where the halo's inner region rapidly increases in density and decreases in size. The N-body simulations used to study this…

We study analytically the coarse and fine-grained distribution function established by the self-similar infall of collisionless matter. We find this function explicitly for isotropic and spherically symmetric systems in terms of…

Astrophysics · Physics 2009-11-10 R. N. Henriksen

We propose a methodological framework to perform forward asteroseismic modeling of stars with a convective core, based on gravity-mode oscillations. These probe the near-core region in the deep stellar interior. The modeling relies on a set…

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…

High Energy Astrophysical Phenomena · Physics 2018-09-11 Stuart L. Shapiro