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200 papers

High-quality optical rotation curves for a sample of low-luminosity spirals evidence that the dark halos around galaxies are inconsistent with the output of proper CDM simulations. In fact, dark halos enveloping stellar disks are structures…

Astrophysics · Physics 2009-11-06 P. Salucci , A. Borriello

The indefinite increase of temperature predicted by the solar wind expansion in the direction parallel to the interplanetary magnetic field is already notorious for not being confirmed by the observations. In hot and dilute plasmas from…

Solar and Stellar Astrophysics · Physics 2016-04-20 M. Lazar , S. M. Shaaban , S. Poedts , Š. Štverák

Hall instability in electron magnetohydrodynamics is interpreted as the shear-Hall instability driven jointly by helicoidal oscillations and shear in the electron current velocity. This explanation suggests an antiparallel orientation of…

Plasma Physics · Physics 2021-07-21 Leonid Kitchatinov

Motivated by the LMC's impact on the integral of motion space of the stellar halo, we run an $N$-body merger simulation to produce a population of halo-like stars. We subsequently move to a test particle simulation, in which the LMC…

Astrophysics of Galaxies · Physics 2023-07-26 Elliot Y. Davies , Adam M. Dillamore , Vasily Belokurov , N. Wyn Evans

The presence of dust grains profoundly affects the diffusion of the magnetic field in molecular clouds. When the electrons and ions are well coupled to the magnetic field and charged grains are only indirectly coupled, emergent Hall…

Astrophysics of Galaxies · Physics 2019-02-13 B. P. Pandey , S. V. Vladimirov

The normal mode theory for warping of galaxy disks, in which disks are assumed to be tilted with respect to the equator of a massive, flattened dark halo, assumes a rigid, fixed halo. However, consideration of the back-reaction by a…

Astrophysics · Physics 2007-05-23 Konrad Kuijken

We use hydrodynamic simulations with adaptive grid refinement to study the dependence of hot gas flows in X-ray luminous giant elliptical galaxies on the efficiency of heat supply to the gas. We consider a number of potential heating…

Astrophysics · Physics 2009-10-31 A. Kritsuk , T. Plewa , E. Mueller

We calculate the evolution of molecular line profiles of HCO$^+$ and C$^{18}$O toward a dense core thatis forming inside a magnetized turbulent molecular cloud. Features of the profiles can be affected more significantly by coupled velocity…

Astrophysics of Galaxies · Physics 2009-07-22 Jeong-Eun Lee , Jongsoo Kim

Using a simple analytic formalism, we demonstrate that significant dark matter self-interactions produce halo cores that obey scaling relations nearly independent of the underlying particle physics parameters such as the annihilation cross…

Astrophysics of Galaxies · Physics 2016-03-16 Henry W. Lin , Abraham Loeb

The occurrence of chaos for test particles moving around a slowly rotating black hole with a dipolar halo is studied using Poincar\'e sections. We find a novel effect, particles with angular momentum opposite to the black hole rotation have…

General Relativity and Quantum Cosmology · Physics 2014-11-17 P. S. Letelier , W. M. Vieira

We study the system constructed by charged scalar fields linearly coupled to asymptotically flat horizonless compact reflecting stars. We obtain bounds on the charge of the scalar field, below which the scalar hairy star is expected to…

General Relativity and Quantum Cosmology · Physics 2018-11-05 Yan Peng

We explore observed dynamical trends in a wide range of dark matter dominated systems (about seven orders of magnitude in mass) to constrain hypothetical dark matter candidates and scenarios of structure formation. First, we argue that…

Astrophysics · Physics 2009-10-31 Julianne J. Dalcanton , Craig J. Hogan

Photonic systems with time-varying modulations have attracted considerable attention as they allow for the design of non-reciprocal devices without the need for an external magnetic bias. Unlike time-invariant systems, such modulations…

We test the hypothesis that the starless cores may be gravitationally bound clouds supported largely by thermal pressure by comparing observed molecular line spectra to theoretical spectra produced by a simulation that includes…

Astrophysics · Physics 2009-11-13 Eric Keto , George Field

The ion-hose (or fast-ion) instability sets limits on the allowable vacuum in a long-pulse, high current accelerator. Beam-induced ionization of the background gas leads to the formation of an ion channel which couples to the transverse…

Accelerator Physics · Physics 2007-05-23 George J. Caporaso , Jim. F. McCarrick

The behaviour of the transverse momentum fluctuations with the centrality of the collision shown by the Relativistic Heavy Ion Collider data is naturally explained by the clustering of color sources. In this framework, elementary color…

High Energy Physics - Phenomenology · Physics 2009-11-10 E. G. Ferreiro , F. del Moral , C. Pajares

A new so-called `gravitational loss-cone instability' in stellar systems has recently been investigated theoretically in the framework of linear perturbation theory and proved to be potentially important in understanding the physical…

Astrophysics of Galaxies · Physics 2020-01-08 E. V. Polyachenko , P. Berczik , A. Just , I. G. Shukhman

The selfgenerated wave fluctuations are particularly interesting in the solar wind and magnetospheric plasmas, where Coulomb collisions are rare and cannot explain the observed states of quasi-equilibrium. Linear theory predicts that the…

Solar and Stellar Astrophysics · Physics 2015-06-16 M. Lazar , S. Poedts , R. Schlickeiser , D. Ibscher

We consider the Rayleigh-Taylor instability in the early evolution of the rarefied radio bubbles (cavities) observed in many cooling flow clusters of galaxies. The top of a bubble becomes prone to the Rayleigh-Taylor instability as the…

Astrophysics · Physics 2009-11-11 Fabio Pizzolato , Noam Soker

Matter and dark matter in galaxies represent two main components linked by the gravitational interaction. Collisions of galaxies may create an offset between the centers of mass of these components. Ignoring internal dynamics of particles…

Astrophysics of Galaxies · Physics 2026-05-27 V. V. Flambaum , I. B. Samsonov