Particle acceleration at astrophysical shocks: A theory of cosmic ray origin

Blandford, R. D.; Eichler, David

doi:10.1016/0370-1573(87)90134-7

Cited by 1,979 publications

(1,822 citation statements)

References 160 publications

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“…It is believed to to be due to Fermi acceleration in collisionless shocks [1,9], although a first principles understanding of the process is not yet available. The normalization of 0.6×10 44 erg Mpc −3 yr −1 is chosen to account for the observed flux.…”

Section: Analysis Of Current Datamentioning

confidence: 99%

High-energy cosmic rays: Puzzles, models, and giga-ton neutrino telescopes

Waxman

2004

Pramana - J Phys

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Abstract. The existence of cosmic rays of energies exceeding 10 20 eV is one of the mysteries of high energy astrophysics. The spectrum and the high energy to which it extends rule out almost all suggested source models. The challenges posed by observations to models for the origin of high energy cosmic rays are reviewed, and the implications of recent new experimental results are discussed. Large area high energy cosmic ray detectors and large volume high energy neutrino detectors currently under construction may resolve the high energy cosmic ray puzzle, and shed light on the identity and physics of the most powerful accelerators in the universe.

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Section: Analysis Of Current Datamentioning

confidence: 99%

High-energy cosmic rays: Puzzles, models, and giga-ton neutrino telescopes

Waxman

2004

Pramana - J Phys

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“…The current paradigm is that the bulk of the cosmic-rays (up to the "knee" at 3 × 10 15 eV) are accelerated at the blast waves generated by supernova explosions in our galaxy (Blandford & Eichler 1987). Indeed supernova remnants (SNRs) are all nonthermal radio emitters, attesting of the presence of accelerated electrons at energies of 1 GeV or so in larger amounts than in the average interstellar medium.…”

Section: Introductionmentioning

confidence: 99%

Geometry of the non-thermal emission in SN 1006

Rothenflug¹,

Ballet²,

Dubner

et al. 2004

A&A

125

158

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Abstract. SN 1006 is the prototype of shell supernova remnants, in which non-thermal synchrotron emission dominates the X-ray spectrum. The non-thermal emission is due to the cosmic-ray electrons accelerated behind the blast wave. The X-ray synchrotron emission is due to the highest energy electrons, and is thus a tracer of the maximum energy electrons may reach behind a shock. We have put together all XMM-Newton observations to build a full map of SN 1006. The very low brightness above 2 keV in the interior indicates that the bright non-thermal limbs are polar caps rather than an equator. This implies that the ambient magnetic field runs southwest to northeast, along the Galactic plane. We used a combined VLA/Parkes radio map to anchor the spectrum at low energy, and model the spectra with synchrotron emission from a cut-off power-law electron distribution, plus a thermal component. We present radial and azimuthal profiles of the cut-off frequency. The cut-off frequency decreases steeply with radius towards the center and with position angle away from the maximum emission. The maximum energy reached by accelerated particles, as well as their number, must be higher at the bright limbs than elsewhere. This implies interesting constraints for acceleration at perpendicular shocks. Overall the XMM-Newton data is consistent with the model in which the magnetic field is amplified where acceleration is efficient.

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“…Putting these concerns to the side for the moment, we marvel instead that the cosmic-ray proton spectrum is so close to a power law, as expected in first-order testparticle Fermi acceration theory, as reviewed in [17]. One of the central results of this theory is that the distribution function of transmitted particles f ( p) ∝ p −3r/(r −1) , so that d N/dp ∝ p −A tp , where the test-particle spectral index…”

Section: The Cosmic-ray Spectrum In the Local Interstellar Mediummentioning

confidence: 91%

Impact of Fermi-LAT and AMS-02 results on cosmic-ray astrophysics

Dermer

2015

EPJ Web of Conferences

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Abstract. This article reviews a few topics relevant to Galactic cosmic-ray astrophysics, focusing on the recent AMS-02 data release and Fermi Large Area Telescope data on the diffuse Galactic γ -ray emissivity. Calculations are made of the diffuse cosmic-ray induced p + p → π 0 → 2γ spectra, normalized to the AMS-02 cosmic-ray proton spectrum at ≈ 10 − 100 GV, with and without a hardening in the cosmic-ray proton spectrum at rigidities R 300 GV. A single power-law momentum "shock" spectrum for the local interstellar medium cosmic-ray proton spectrum cannot be ruled out from the γ -ray emissivity data alone without considering the additional contribution of electron bremsstrahlung. Metallicity corrections are discussed, and a maximal range of nuclear enhancement factors from 1.52 to 1.92 is estimated. Origins of the 300 GV cosmic-ray proton and α-particle hardening are discussed.

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Particle acceleration at astrophysical shocks: A theory of cosmic ray origin

Cited by 1,979 publications

References 160 publications

High-energy cosmic rays: Puzzles, models, and giga-ton neutrino telescopes

High-energy cosmic rays: Puzzles, models, and giga-ton neutrino telescopes

Geometry of the non-thermal emission in SN 1006

Impact of Fermi-LAT and AMS-02 results on cosmic-ray astrophysics

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