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Related papers: Collisionless shock in a partially ionized medium.…

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We present the results from Fabry-Perot imaging spectroscopy of the Balmer-dominated supernova remnant DEM L71 (0505-67.9) in the LMC. Spectra extracted from the entire circumference of the blast wave reveal the broad and narrow component…

Astrophysics · Physics 2009-11-07 Parviz Ghavamian , Cara E. Rakowski , John P. Hughes , T. B. Williams

In situ observations of energetic particles at the Earth's bow-shock that are attainable by the satellite missions have long created the opinion that electrons are most efficiently accelerated in a quasi-perpendicular shock geometry.…

High Energy Astrophysical Phenomena · Physics 2020-10-07 Adrian Hanusch , Tatyana Liseykina , Mikhail Malkov

When the neutral interstellar medium is exposed to EUV and soft X ray radiation, the argon atoms in it are far more susceptible to being ionized than the hydrogen atoms. We make use of this fact to determine the level of ionization in the…

Astrophysics of Galaxies · Physics 2013-01-29 Edward B. Jenkins

Most of the plasma microphysics which shapes the acceleration process of particles at collisionless shock waves takes place in the cosmic-ray precursor, through the interaction of accelerated particles with the unshocked plasma. Detecting…

High Energy Astrophysical Phenomena · Physics 2017-05-03 Ruben Zakine , Martin Lemoine

The topic of this review is the current state of our knowledge about the degree of initial equilibration between electrons, protons and ions at supernova remnant (SNR) shocks. Specifically, the question has been raised as to whether there…

Astrophysics · Physics 2009-11-10 Cara E. Rakowski

We consider internal shocks as the main dissipation mechanism responsible for the emission in blazars and show that it can satisfactorily account for the properties of all blazars. In particular, we extend previous work (Spada et al. 2001)…

Astrophysics · Physics 2009-11-10 Dafne Guetta , Gabriele Ghisellini , Davide Lazzati , Annalisa Celotti

The selfconsistent steady state solution for a strong shock, significantly modified by accelerated particles is obtained on the level of a kinetic description, assuming Bohm-type diffusion. The original problem that is commonly formulated…

Astrophysics · Physics 2009-10-30 M. A. Malkov

A full particle simulation study is carried out for studying microinstabilities generated at the shock front of perpendicular collisionless shocks. The structure and dynamics of shock waves are determined by Alfven Mach number and plasma…

Plasma Physics · Physics 2015-06-04 Takayuki Umeda , Yoshitaka Kidani , Shuichi Matsukiyo , Ryo Yamazaki

We report on the temporally and spatially resolved detection of the precursory stages that lead to the formation of an unmagnetized, supercritical collision-less shock in a laser-driven laboratory experiment. The measured evolution of the…

High Energy Astrophysical Phenomena · Physics 2015-06-15 H Ahmed , ME Dieckmann , L Romagnani , D Doria , G Sarri , M Cherchez , E Ianni , I Kourakis , AL Giesecke , M Notley , R Prasad , K Quinn , O Willi , M Borghesi

The ratios of hydrogen Balmer emission line intensities in cataclysmic variables are signatures of the physical processes that produce them. To quantify those signatures relative to classifications of cataclysmic variable types, we applied…

Astrophysics · Physics 2009-11-11 Gordon E. Sarty , Kinwah Wu

We investigate the ionization structure of the nebular gas in M83 using the line diagnostic diagram, [O III](5007 \degA)/H{\beta} vs. [S II](6716 \deg A+6731 \deg A)/H{\alpha} with the newly available narrowband images from the Wide Field…

With Spitzer IRS we have obtained sensitive low-resolution spectroscopy from 5 to 35 microns for six supernova remnants (SNRs) that show evidence of shocked molecular gas: Kes 69, 3C 396, Kes 17, G346.6-0.2, G348.5-0.0 and G349.7+0.2.…

Solar and Stellar Astrophysics · Physics 2011-02-11 John W. Hewitt , Jeonghee Rho , Morten Andersen , William T. Reach

We consider the one-dimensional propagation of electromagnetic waves in a weakly nonlinear and low-contrast spatially inhomogeneous medium with no energy dissipation. We focus on the case of a periodic medium, in which dispersion enters…

Pattern Formation and Solitons · Physics 2010-11-19 Gideon Simpson , Michael I. Weinstein

We explore electron pre-acceleration at high Mach-number nonrelativistic perpendicular shocks at, e.g., young supernova remnants, which are a prerequisite of further acceleration to very high energies via diffusive shock acceleration. Using…

High Energy Astrophysical Phenomena · Physics 2019-11-06 Artem Bohdan , Jacek Niemiec , Martin Pohl , Yosuke Matsumoto , Takanobu Amano , Masahiro Hoshino

With Hubble Space Telescope Wide-Field Planetary Camera 2 observations of the Cygnus Loop supernova remnant, we examine the interaction of an interstellar cloud with the blast wave on physical scales of 10^15 cm. The shock front is…

Astrophysics · Physics 2009-11-06 N. A. Levenson , James R. Graham

In this paper we investigate effects of neutral particles on shocks propagating into the partially ionized medium. We find that for 120 km/s < u_{sh} < 3000 km/s (u_{sh} is the shock velocity), about ten percent of upstream neutral…

High Energy Astrophysical Phenomena · Physics 2015-06-04 Yutaka Ohira

A thorough understanding of collisionless shocks requires knowledge of how different ion species are accelerated across the shock. We investigate a bow shock crossing using the Magnetospheric Multiscale spacecraft after a coronal mass…

Understanding the heating of electrons to quasi-thermal energies at collisionless shocks has broad implications for plasma astrophysics. It directly impacts the interpretation of X-ray spectra from shocks, is important for understanding how…

Astrophysics · Physics 2009-11-13 Cara E. Rakowski , J. Martin Laming , Parviz Ghavamian

Supernova remnants are believed to be the major contributors to Galactic cosmic rays. In this paper, we explore how the non-thermal emission from young remnants can be used to probe the production of energetic particles at the shock (both…

High Energy Astrophysical Phenomena · Physics 2015-06-19 Gilles Ferrand , Anne Decourchelle , Samar Safi-Harb

We analyze the behavior of shock waves in nonlinear theories of electrodynamics. For this, by use of generalized Hadamard step functions of increasing order, the electromagnetic potential is developed in a series expansion near the shock…

Mathematical Physics · Physics 2015-12-07 Christoph Minz , Horst-Heino von Borzeszkowski , Thoralf Chrobok , Gerold Schellstede