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We study the impact of gas motions on the polarization of bright X-ray emission lines from the hot intercluster medium (ICM). The polarization naturally arises from resonant scattering of emission lines owing to a quadrupole component in…

High Energy Astrophysical Phenomena · Physics 2015-05-14 I. V. Zhuravleva , E. M. Churazov , S. Yu. Sazonov , R. A. Sunyaev , W. Forman , K. Dolag

In this work, we investigate synchrotron emission and the observational signatures of anisotropic non-thermal electrons during magnetic-flux eruptions in a magnetically arrested disk, using 3D GRMHD simulations. Non-thermal electrons are…

High Energy Astrophysical Phenomena · Physics 2026-05-18 Fan Zhou , Jiewei Huang , Yuehang Li , Zhenyu Zhang , Yehui Hou , Minyong Guo , Bin Chen

The anisotropy and polarization of the cosmic microwave background radiation (CMBR) induced by the scalar and tensor metric perturbations are computed in the long-wavelength limit. It is found that the large-scale polarization of CMBR…

Astrophysics · Physics 2009-10-22 Ka Lok Ng , Kin-Wang Ng

The analysis of X-ray and Sunyaev-Zel\'dovich measurements of the intracluster medium (ICM) assumes that electrons are in thermal equilibrium with ions in the plasma. However, electron-ion equilibration timescales can be comparable to the…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-20 Camille Avestruz , Daisuke Nagai , Erwin T. Lau , Kaylea Nelson

Magnetized high-energy-density plasmas can often have strong electromagnetic fluctuations whose correlation scale is smaller than the electron Larmor radius. Radiation from the electrons in such plasmas, which markedly differs from both…

Plasma Physics · Physics 2016-04-07 Brett D. Keenan , Mikhail V. Medvedev

This paper considers the problem of modeling the light polarization that emerges from an astrophysical plasma composed of atoms whose excitation state is significantly influenced by the anisotropy of the incident radiation field. In…

Solar and Stellar Astrophysics · Physics 2011-05-03 Javier Trujillo Bueno

The inhomogeneous ionization state of the universe when the first sources of ionizing radiation appeared should lead to anisotropies in the polarization of the cosmic microwave background. We use cosmological simulations of the process by…

We show that under very general conditions, cluster plasmas threaded by weak magnetic fields are subject to very fast growing plasma instabilities driven by the anisotropy of the plasma pressure (viscous stress) with respect to the local…

Astrophysics · Physics 2008-11-26 A. A. Schekochihin , S. C. Cowley , R. M. Kulsrud , G. W. Hammett , P. Sharma

Nature's most powerful high-energy sources are capable of accelerating particles to high energy and radiate it away on extremely short timescales, even shorter than the light crossing time of the system. It is yet unclear what physical…

Plasma Physics · Physics 2022-01-03 Luca Comisso , Lorenzo Sironi

In gamma-ray bursts (GRBs), the electron pitch angle ($\alpha$) is usually assumed to be isotropically distributed. However, recent numerical simulations indicate that only the high-energy electrons (with Lorentz factors…

High Energy Astrophysical Phenomena · Physics 2026-04-27 Kang-Fa Cheng , Kai-Xian Luo , Xiao-Hong Zhao , Jirong Mao , Hong-Bang Liu , Yu-Hang Mo , Jin-Rong Huang , Rong-Li Weng , Wen-Jie Xie , Gao-Jin Yu

A variety of nonthermal characteristics like kinetic, e.g., temperature, anisotropies and suprathermal populations (enhancing the high energy tails of the velocity distributions) are revealed by the in-situ observations in the solar wind…

Solar and Stellar Astrophysics · Physics 2016-12-06 S. M. Shaaban , M. Lazar , S. Poedts , A. Elhanbaly

We calculate the polarization of radiation from thick accretion disks with vertically averaged global magnetic field. The polarization arises as a result of the radiation scattering by free electrons in magnetized plasma of a disk. We…

Astrophysics · Physics 2007-05-23 Yu. N. Gnedin , N. A. Silant'ev , P. S. Shternin

In this paper we review the possible radiation mechanisms for the observed non-thermal emission in clusters of galaxies, with a primary focus on the radio and hard X-ray emission. We show that the difficulty with the non-thermal,…

Astrophysics · Physics 2009-11-13 V. Petrosian , Y. Rephaeli , A. Bykov

The thermal radiation of small conducting particles was investigated in the region where the Stephan-Boltzmann law is not valid and strongly overestimates radiation losses. The new criterion for the particle size, at which black body…

Optics · Physics 2009-11-11 Yu. V. Martynenko , L. I. Ognev

Space plasmas in various astrophysical setups can often be both very hot and dilute, making them highly susceptible to waves and fluctuations, which are generally self-generated and maintained by kinetic instabilities. In this sense, we…

Protons (ionized hydrogen) in the solar wind frequently exhibit distinct temperatures ($T_{\perp p}$ and $T_{\parallel p}$) perpendicular and parallel to the plasma's background magnetic-field. Numerous prior studies of the interplanetary…

The behaviour of a strongly-magnetized collisional electron-positron plasma which is optically thin to cyclotron radiation is considered, and the distribution functions accessible to it on the various timescales in the system are…

Plasma Physics · Physics 2021-02-17 Daniel Kennedy , Per Helander

In low-collisionality plasmas, velocity-space instabilities are a key mechanism providing an effective collisionality for the plasma. We use particle-in-cell (PIC) simulations to study the interplay between electron and ion-scale…

Plasma Physics · Physics 2016-08-12 Mario Riquelme , Eliot Quataert , Daniel Verscharen

In collision-poor plasmas from space, e.g., the solar wind and planetary magnetospheres, the kinetic anisotropy of the plasma particles is expected to be regulated by the kinetic instabilities. Driven by an excess of ion (proton)…

Space Physics · Physics 2016-05-12 S. M. Shaaban , M. Lazar , S. Poedts , A. Elhanbaly

Radiation which has a quadrupole component of anisotropy, can get polarized by Thomson scattering from charged particles. In the cosmological context, the microwave background photons develop significant quadrupole anisotropy as they free…

Astrophysics · Physics 2009-10-30 T. R. Seshadri , K. Subramanian