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Related papers: On relaxation processes in collisionless mergers

200 papers

We investigate the bursts of electromagnetic and scalar radiation resulting from the collision, and merger of oscillons made from axion-like particles using 3+1 dimensional lattice simulations of the coupled axion-gauge field system. The…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-17 Mustafa A. Amin , Zong-Gang Mou

The excursion set theory of halo formation is modified by adopting the fractional Brownian motion, to account for possible correlation between merging steps. We worked out analytically the conditional mass function, halo merging rate and…

Astrophysics · Physics 2009-11-13 Jun Pan , Yougang Wang , Xuelei Chen , Luis Teodoro

Predicting the merger timescale ($\tau_{\rm merge}$) of merging dark matter halos, based on their orbital parameters and the structural properties of their hosts, is a fundamental problem in gravitational dynamics that has important…

Astrophysics of Galaxies · Physics 2020-10-28 Rhys J. J. Poulton , Chris Power , Aaron S. G. Robotham , Pascal J. Elahi , Claudia del P. Lagos

Magnetic reconnection requires the violation of the frozen-in condition which ties gyrating charged particles to the magnetic field inhibiting diffusion. Ongoing reconnection has been identified in near-Earth space as being responsible for…

Space Physics · Physics 2014-01-24 R. A. Treumann , W. Baumjohann

Cosmological N-body simulations were performed to study the evolution of the phase-space density Q = rho/sigma^3 of dark matter halos. No significant differences in the scale relations Q ~ sigma^(-2.1) or Q ~ M^(-0.82) are seen for "cold"…

Astrophysics · Physics 2016-08-16 Sébastien Peirani , Fabrice Durier , José Antonio De Freitas Pacheco

We demonstrate the existence of an enhanced rate of angular momentum relaxation in nearly Keplerian star clusters, such as those found in the centers of galactic nuclei containing massive black holes. The enhanced relaxation arises because…

Astrophysics · Physics 2009-10-28 Kevin P. Rauch , Scott Tremaine

We investigate the effect of particle inertia on the merger of co-rotating dusty vortex pairs at semi-dilute concentrations. In a particle-free flow, the merger is triggered once the ratio of vortex core size to vortex separation reaches a…

Fluid Dynamics · Physics 2023-12-06 Shuai Shuai , Anubhab Roy , M. Houssem Kasbaoui

Dynamical interactions between colliding spiral galaxies strongly affect the state and distribution of their interstellar gas. Observations indicate that interactions funnel gas toward the nuclei, fueling bursts of star formation and…

Astrophysics of Galaxies · Physics 2018-07-04 Kelly Blumenthal , Joshua Barnes

The effect of compressibility in hydrodynamic vortex merging has been discussed. In the past, in incompressible limit it has been observed that the merging of a collection of intense point-like vortices arranged uniformly outside a circular…

Fluid Dynamics · Physics 2020-01-01 Rupak Mukherjee , Akanksha Gupta , Rajaraman Ganesh

We present the results of three-dimensional (3D) ideal magnetohydrodynamics (MHD) simulations on the dynamics of a perpendicularly inhomogeneous plasma disturbed by propagating Alfv\'enic waves. Simpler versions of this scenario have been…

Solar and Stellar Astrophysics · Physics 2017-11-03 Norbert Magyar , Tom Van Doorsselaere , Marcel Goossens

We extend our previous analysis of holographic heavy ion collisions in non-conformal theories. We provide a detailed description of our numerical code. We study collisions at different energies in gauge theories with different degrees of…

The hydrodynamical cosmological simulation \eagle{} is used to model the Halo Occupation Distribution (HOD) of moderate X-ray luminosity active galactic nuclei (mXAGN), extending previous work using only dark matter simulations and…

Astrophysics of Galaxies · Physics 2025-06-09 Liliana Altamiran-Dévora , Hector Aceves , Angel Castro , Takamitsu Miyaji

In two-dimensional (2D) inviscid incompressible flow, low background vorticity distribution accelerates intense vortices (clumps) to merge each other and to array in the symmetric pattern which is called ``vortex crystals''; they are…

Statistical Mechanics · Physics 2009-11-10 Takeshi Yoshida , Mitsusada M. Sano

Simulations and observations of the low-latitude magnetosphere-magnetosheath boundary layer indicate that the Kelvin-Helmholtz instability (KHI) drives vortex structures that enhance plasma mixing and magnetic reconnection, influencing…

Plasma Physics · Physics 2026-05-06 Silvia Ferro , Fabio Bacchini , Giuseppe Arrò , Francesco Pucci , Pierre Henri

We uncover the dynamics of particles with Gaussian core interactions across melting in pure and disordered two-dimensional (2D) systems. Intriguing signatures of cooperative motion of particles in string-like paths are found at low…

Soft Condensed Matter · Physics 2024-11-26 Saikat Dutta , Prashanti Jami , Pinaki Chaudhuri , Chandan Dasgupta , Amit Ghosal

We present the results of high-resolution AP3M+SPH simulations of merging clusters of galaxies. We find that the compression and shocking of the core gas during a merger can lead to large increases in bolometric X-ray luminosities and…

Astrophysics · Physics 2009-11-06 Benedict W. Ritchie , Peter A. Thomas

Systems containing active components are intrinsically out of equilibrium, while binary mixtures reach their equilibrium configuration when complete phase separation is achieved. Active particles are found to stabilise non-equilibrium…

Soft Condensed Matter · Physics 2025-03-11 Javier Diaz , Ignacio Pagonabarraga

Why do galactic bars rotate with high pattern speeds, when dynamical friction should rapidly couple the bar to the massive, slowly rotating dark halo? This longstanding paradox may be resolved by considering the dynamical interactions…

Astrophysics · Physics 2009-10-31 S. Tremaine , J. P. Ostriker

We extend the random-walk model of Vitvitska et al. for predicting the spins of dark matter halos from their merger histories. Using updated merger rates, orbital parameter distributions, and N-body constraints we show that this model can…

Astrophysics of Galaxies · Physics 2020-07-08 Andrew Benson , Christoph Behrens , Yu Lu

In a granular gas, inelastic collisions produce an instability in which the constituent particles cluster heterogeneously. These clusters then interact with each other, further decreasing their kinetic energy. We report experiments of the…

Soft Condensed Matter · Physics 2015-06-17 Justin C. Burton , Peter Y. Lu , Sidney R. Nagel