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We have calculated the cosmic ray (CR) acceleration at young remnants from Type Ia supernovae expanding into a uniform interstellar medium (ISM). Adopting quasi-parallel magnetic fields, gasdynamic equations and the diffusion convection…

Astrophysics · Physics 2008-11-26 Hyesung Kang

The supernova remnant G347.3--0.5 emits a featureless power-law in X-rays, thought to indicate shock-acceleration of electrons to high energies. We here produce a broad-band spectrum of the bright NW limb of this source by combining radio…

Astrophysics · Physics 2009-11-06 Donald C. Ellison , Patrick Slane , Bryan M. Gaensler

A novel collisionless shock jump condition is suggested by modeling the entropy production at the shock transition region. We also calculate downstream developments of the atomic ionization balance and the ion temperature relaxation in…

High Energy Astrophysical Phenomena · Physics 2022-07-27 Jiro Shimoda , Yutaka Ohira , Aya Bamba , Yukikatsu Terada , Ryo Yamazaki , Tsuyoshi Inoue , Shuta J. Tanaka

We present results of semi-analytic calculations which show clear evidence for changes in the non-equilibrium ionization behind a supernova remnant forward shock undergoing efficient diffusive shock acceleration (DSA). The efficient…

High Energy Astrophysical Phenomena · Physics 2011-02-11 Daniel J. Patnaude , Donald C. Ellison , Patrick Slane

The momentum distribution of particles accelerated at strong non-relativistic shocks may be influenced by the spatial distribution of the flow speed around the shock. This phenomenon becomes evident in the cosmic-ray modified shock, where…

High Energy Astrophysical Phenomena · Physics 2024-08-14 O. Petruk , T. Kuzyo

We have extended a simple model of nonlinear diffusive shock acceleration (Berezhko and Ellison 1999) to include the injection and acceleration of electrons and the production of photons from bremsstrahlung, synchrotron, inverse-Compton,…

Astrophysics · Physics 2009-10-31 Donald C. Ellison , Evgeny G. Berezhko , Matthew G. Baring

We explore the physics of shock evolution and particle acceleration in non-relativistic collisionless shocks using multidimensional hybrid simulations. We analyze a wide range of physical parameters relevant to the acceleration of cosmic…

High Energy Astrophysical Phenomena · Physics 2015-05-28 L. Gargaté , A. Spitkovsky

We model the broad-band emission from SNR RX J1713.7-3946 including, for the first time, a consistent calculation of thermal X-ray emission together with non-thermal emission in a nonlinear diffusive shock acceleration (DSA) model. Our…

High Energy Astrophysical Phenomena · Physics 2015-05-14 Donald C. Ellison , Daniel J. Patnaude , Patrick Slane , John Raymond

If highly efficient, cosmic ray production can have a significant effect on the X-ray emission from SNRs as well as their dynamical evolution. Using hydrodynamical simulations including diffusive shock acceleration, we produce spectra for…

While supernova remnants (SNRs) have long been considered prime candidates for the source of cosmic rays, at least to energies up to ~10^14 eV, it is only over the past several years that direct evidence of such energetic particles in SNRs…

Astrophysics · Physics 2007-05-23 Patrick Slane

We present the first far ultraviolet (FUV) spectra of the four known Balmer-dominated supernova remnants (SNRs) in the Large Magellanic Cloud, acquired with the Far Ultraviolet Spectroscopic Explorer. The remnants DEM L 71 (0505-67.9),…

Astrophysics · Physics 2014-10-13 Parviz Ghavamian , William P. Blair , Ravi Sankrit , John P. Hughes , John C. Raymond

We present evidence for cosmic ray acceleration at the forward shock in Tycho's supernova remnant (SNR) from three X-ray observables: (1) the proximity of the contact discontinuity to the forward shock, or blast wave, (2) the morphology of…

Broad emission lines of active galactic nuclei (AGNs) originate from the broad-line region (BLR), consisting of dense gas clouds in orbit around an accreting supermassive black hole. Understanding the geometry and kinematics of the region…

Astrophysics of Galaxies · Physics 2024-08-29 Sha-Sha Li , Hai-Cheng Feng , H. T. Liu , J. M. Bai , Xiang Ji , Cheng Cheng , Kai-Xing Lu , Jian-Guo Wang , Rui Li

Cosmic-ray production in young supernova remnant (SNR) shocks is expected to be efficient and strongly nonlinear. In nonlinear, diffusive shock acceleration, compression ratios will be higher and the shocked temperature lower than…

Astrophysics · Physics 2009-10-31 Donald C. Ellison

According to the most popular model for the origin of cosmic rays (CRs), supernova remnants (SNRs) are the site where CRs are accelerated. Observations across the electromagnetic spectrum support this picture through the detection of…

High Energy Astrophysical Phenomena · Physics 2021-01-27 S. Orlando , M. Miceli , S. Ustamujic , A. Tutone , E. Greco , O. Petruk , F. Bocchino , G. Peres

Molecular emission arising from the interactions of supernova remnant (SNR) shock waves and molecular clouds provide a tool for studying the dispersion and compression that might kick-start star formation as well as understanding cosmic ray…

Astrophysics of Galaxies · Physics 2024-03-04 Nguyen Fuda , Le-Ngoc Tram , William T. Reach

We have developed an inversion method for determination of the characteristics of the acceleration mechanism directly and non-parametrically from observations, in contrast to the usual forward fitting of parametric model variables to…

High Energy Astrophysical Phenomena · Physics 2015-06-17 Vahé Petrosian , Qingrong Chen

Supernova remnants (SNRs) are one of the most energetic astrophysical events and are thought to be the dominant source of Galactic cosmic rays (CRs). A recent report on observations from the Fermi satellite has shown a signature of pion…

High Energy Astrophysical Phenomena · Physics 2015-08-26 Soonyoung Roh , Shu-ichiro Inutsuka , Tsuyoshi Inoue

An overview is given of multiwavelength observations of young supernova remnants, with a focus on the observational signatures of efficient cosmic ray acceleration. Some of the effects that may be attributed to efficient cosmic ray…

Astrophysics · Physics 2009-11-13 Jacco Vink

Optical and near-UV continuum emissions in flares contribute substantially to flare energy budget. Two mechanisms play an important role for continuum emission in flares: hydrogen recombination after sudden ionization at chromospheric…

Solar and Stellar Astrophysics · Physics 2021-10-13 Reetika Joshi , Brigitte Schmieder , Petr Heinzel , James Tomin , Ramesh Chandra , Nicole Vilmer