Galactic Cosmic Rays from Supernova Remnants. I. A Cosmic‐Ray Composition Controlled by Volatility and Mass‐to‐Charge Ratio

Abstract. It is generally believed that the cosmic ray spectrum below the knee is of Galactic origin, although the exact sources making up the entire cosmic ray energy budget are still unknown. Including effects of magnetic amplification, Supernova Remnants (SNR) could be capable of accelerating cosmic rays up to a few PeV and they represent the only source class with a sufficient non-thermal energy budget to explain the cosmic ray spectrum up to the knee. Now, gamma-ray measurements of SNRs for the first time allow to derive the cosmic ray spectrum at the source, giving us a first idea of the concrete, possible individual contributions to the total cosmic ray spectrum. In this contribution, we use these features as input parameters for propagating cosmic rays from its origin to Earth using GALPROP in order to investigate if these supernova remnants reproduce the cosmic ray spectrum and if supernova remnants in general can be responsible for the observed energy budget.

Download Full-text

Direct Numerical Simulations of Cosmic-ray Acceleration at Dense Circumstellar Medium: Magnetic-field Amplification and Maximum Energy

The Astrophysical Journal ◽

10.3847/1538-4357/ac21ce ◽

2021 ◽

Vol 922 (1) ◽

pp. 7

Author(s):

Tsuyoshi Inoue ◽

Alexandre Marcowith ◽

Gwenael Giacinti ◽

Allard Jan van Marle ◽

Shogo Nishino

Keyword(s):

Cosmic Rays ◽

Mass Loss ◽

Supernova Remnants ◽

Mass Loss Rate ◽

Spherical Geometry ◽

Cosmic Ray ◽

Galactic Cosmic Rays ◽

Maximum Energy ◽

Blast Waves ◽

Loss Rates

Abstract Galactic cosmic rays are believed to be accelerated at supernova remnants. However, whether supernova remnants can be PeV is still very unclear. In this work we argue that PeV cosmic rays can be accelerated during the early phase of a supernova blast-wave expansion in dense red supergiant winds. We solve in spherical geometry a system combining a diffusive–convection equation that treats cosmic-ray dynamics coupled to magnetohydrodynamics to follow gas dynamics. A fast shock expanding in a dense ionized wind is able to trigger fast, non-resonant streaming instability over day timescales and energizes cosmic rays even under the effect of p–p losses. We find that such environments produce PeV blast waves, although the maximum energy depends on various parameters such as the injection rate and mass-loss rate of the winds. Multi-PeV energies can be reached if the progenitor mass-loss rates are of the order of 10−3 M ⊙ yr−1. It has been recently proposed that, prior to the explosion, hydrogen-rich massive stars can produce enhanced mass-loss rates. These enhanced rates would then favor the production of a PeV phase in early times after shock breakout.

Download Full-text

Supernova remnants and the origin of cosmic rays

Proceedings of the International Astronomical Union ◽

10.1017/s1743921313009630 ◽

2013 ◽

Vol 9 (S296) ◽

pp. 305-314

Author(s):

Jacco Vink

Keyword(s):

Synchrotron Radiation ◽

Cosmic Rays ◽

Magnetic Fields ◽

Supernova Remnants ◽

Supernova Remnant ◽

Gamma Ray ◽

Cosmic Ray ◽

Galactic Cosmic Rays ◽

Long Time ◽

Gamma Ray Emission

AbstractSupernova remnants have long been considered to be the dominant sources of Galactic cosmic rays. For a long time the prime evidence consisted of radio synchrotron radiation from supernova remnants, indicating the presence of electrons with energies of several GeV. However, in order to explain the cosmic ray energy density and spectrum in the Galaxy supernova remnant should use 10% of the explosion energy to accelerate particles, and about 99% of the accelerated particles should be protons and other atomic nuclei.Over the last decade a lot of progress has been made in providing evidence that supernova remnant can accelerate protons to very high energies. The evidence consists of, among others, X-ray synchrotron radiation from narrow regions close to supernova remnant shock fronts, indicating the presence of 10-100 TeV electrons, and providing evidence for amplified magnetic fields, gamma-ray emission from both young and mature supernova remnants. The high magnetic fields indicate that the condition for accelerating protons to >1015 eV are there, whereas the gamma-ray emission from some mature remnants indicate that protons have been accelerated.

Download Full-text

Cosmic rays and stochastic magnetic reconnection in the heliotail

Nonlinear Processes in Geophysics ◽

10.5194/npg-19-351-2012 ◽

2012 ◽

Vol 19 (3) ◽

pp. 351-364 ◽

Cited By ~ 8

Author(s):

P. Desiati ◽

A. Lazarian

Keyword(s):

Magnetic Field ◽

Cosmic Rays ◽

Magnetic Reconnection ◽

Supernova Remnants ◽

Average Energy ◽

Cosmic Ray ◽

Galactic Cosmic Rays ◽

Shock Acceleration ◽

Diffusive Shock Acceleration ◽

The Galaxy

Abstract. Galactic cosmic rays are believed to be generated by diffusive shock acceleration processes in Supernova Remnants, and the arrival direction is likely determined by the distribution of their sources throughout the Galaxy, in particular by the nearest and youngest ones. Transport to Earth through the interstellar medium is expected to affect the cosmic ray properties as well. However, the observed anisotropy of TeV cosmic rays and its energy dependence cannot be explained with diffusion models of particle propagation in the Galaxy. Within a distance of a few parsec, diffusion regime is not valid and particles with energy below about 100 TeV must be influenced by the heliosphere and its elongated tail. The observation of a highly significant localized excess region of cosmic rays from the apparent direction of the downstream interstellar flow at 1–10 TeV energies might provide the first experimental evidence that the heliotail can affect the transport of energetic particles. In particular, TeV cosmic rays propagating through the heliotail interact with the 100–300 AU wide magnetic field polarity domains generated by the 11 yr cycles. Since the strength of non-linear convective processes is expected to be larger than viscous damping, the plasma in the heliotail is turbulent. Where magnetic field domains converge on each other due to solar wind gradient, stochastic magnetic reconnection likely occurs. Such processes may be efficient enough to re-accelerate a fraction of TeV particles as long as scattering processes are not strong. Therefore, the fractional excess of TeV cosmic rays from the narrow region toward the heliotail direction traces sightlines with the lowest smearing scattering effects, that can also explain the observation of a harder than average energy spectrum.

Download Full-text

The contribution of nearby supernova remnants on the cosmic ray flux at Earth

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa171 ◽

2020 ◽

Vol 493 (2) ◽

pp. 1960-1981

Author(s):

A A L-Zetoun ◽

A Achterberg

Keyword(s):

Cosmic Rays ◽

Anisotropic Diffusion ◽

Supernova Remnants ◽

Three Dimensional ◽

Cosmic Ray ◽

Galactic Cosmic Rays ◽

Source Position ◽

Galactic Magnetic Field ◽

The Earth ◽

Cosmic Ray Flux

ABSTRACT We consider anisotropic diffusion of Galactic cosmic rays in the Galactic magnetic field, using the Jansson–Farrar model for the field. In this paper, we investigate the influence of source position on the cosmic ray flux at the Earth in two ways: (1) by considering the contribution from cosmic ray sources located in different intervals in Galactocentric radius, and (2) by considering the contribution from a number of specific and individual close-by supernova remnants. Our calculation is performed by using a fully three-dimensional stochastic method. This method is based on the numerical solution of a set of stochastic differential equations, equivalent to Itô formulation, that describes the propagation of the Galactic cosmic rays.

Download Full-text

Steep Cosmic-Ray Spectra with Revised Diffusive Shock Acceleration

The Astrophysical Journal ◽

10.3847/1538-4357/ac22fe ◽

2021 ◽

Vol 922 (1) ◽

pp. 1

Author(s):

Rebecca Diesing ◽

Damiano Caprioli

Keyword(s):

Cosmic Rays ◽

Supernova Remnants ◽

Cosmic Ray ◽

Galactic Cosmic Rays ◽

Shock Acceleration ◽

Analytic Model ◽

Diffusive Shock Acceleration ◽

Energy Distributions ◽

Magnetic Structures ◽

Wide Range

Abstract Galactic cosmic rays (CRs) are accelerated at the forward shocks of supernova remnants (SNRs) via diffusive shock acceleration (DSA), an efficient acceleration mechanism that predicts power-law energy distributions of CRs. However, observations of nonthermal SNR emission imply CR energy distributions that are generally steeper than E −2, the standard DSA prediction. Recent results from kinetic hybrid simulations suggest that such steep spectra may arise from the drift of magnetic structures with respect to the thermal plasma downstream of the shock. Using a semi-analytic model of nonlinear DSA, we investigate the implications that these results have on the phenomenology of a wide range of SNRs. By accounting for the motion of magnetic structures in the downstream, we produce CR energy distributions that are substantially steeper than E −2 and consistent with observations. Our formalism reproduces both modestly steep spectra of Galactic SNRs (∝E −2.2) and the very steep spectra of young radio supernovae (∝E −3).

Download Full-text

Measurement of the cosmic ray proton spectrum from 40 GeV to 100 TeV with the DAMPE satellite

Science Advances ◽

10.1126/sciadv.aax3793 ◽

2019 ◽

Vol 5 (9) ◽

pp. eaax3793 ◽

Cited By ~ 16

Author(s):

◽

Q. An ◽

R. Asfandiyarov ◽

P. Azzarello ◽

P. Bernardini ◽

...

Keyword(s):

Cosmic Rays ◽

Cosmic Radiation ◽

Precise Measurement ◽

Milky Way ◽

Spectral Feature ◽

Dark Matter Particle ◽

Cosmic Ray ◽

Galactic Cosmic Rays ◽

Proton Spectrum ◽

First Time

The precise measurement of the spectrum of protons, the most abundant component of the cosmic radiation, is necessary to understand the source and acceleration of cosmic rays in the Milky Way. This work reports the measurement of the cosmic ray proton fluxes with kinetic energies from 40 GeV to 100 TeV, with 2 1/2 years of data recorded by the DArk Matter Particle Explorer (DAMPE). This is the first time that an experiment directly measures the cosmic ray protons up to ~100 TeV with high statistics. The measured spectrum confirms the spectral hardening at ~300 GeV found by previous experiments and reveals a softening at ~13.6 TeV, with the spectral index changing from ~2.60 to ~2.85. Our result suggests the existence of a new spectral feature of cosmic rays at energies lower than the so-called knee and sheds new light on the origin of Galactic cosmic rays.

Download Full-text

Supernova Remnants: An Introductory Review

Symposium - International Astronomical Union ◽

10.1017/s0074180900180581 ◽

2004 ◽

Vol 218 ◽

pp. 57-64

Author(s):

Jacco Vink

Keyword(s):

Cosmic Rays ◽

Supernova Remnants ◽

Supernova Remnant ◽

Cosmic Ray ◽

Recent Advances ◽

Cosmic Ray Acceleration ◽

Introductory Review

The two main aspects of supernova remnant research addressed in this review are: I. What is our understanding of the progenitors of the observed remnants, and what have we learned from these remnants about supernova nucleosynthesis? II. Supernova remnants are probably the major source of cosmic rays. What are the recent advances in the observational aspects of cosmic ray acceleration in supernova remnants?

Download Full-text

Spectrum of galactic cosmic rays accelerated in supernova remnants

Bulletin of the Russian Academy of Sciences Physics ◽

10.3103/s1062873811030506 ◽

2011 ◽

Vol 75 (3) ◽

pp. 299-301

Author(s):

V. N. Zirakashvili ◽

V. S. Ptuskin ◽

E. S. Seo

Keyword(s):

Cosmic Rays ◽

Supernova Remnants ◽

Galactic Cosmic Rays

Download Full-text

Atmospheric production and transport of 7Be activity by cosmic rays: Modelling with the chemistry-climate model SOCOLv3.0 and comparison with direct measurements

10.5194/egusphere-egu21-2287 ◽

2021 ◽

Author(s):

Kseniia Golubenko ◽

Eugene Rozanov ◽

Genady Kovaltsov ◽

Ari-Pekka Leppänen ◽

Ilya Usoskin

Keyword(s):

Cosmic Rays ◽

Climate Changes ◽

Climate Model ◽

Cosmic Ray ◽

Galactic Cosmic Rays ◽

Cosmogenic Isotopes ◽

Cosmogenic Isotope ◽

The Past ◽

Direct Measurements ◽

First Results

We present the first results of modelling of the short-living cosmogenic isotope 7Be production, deposition, and transport using the chemistry-climate model SOCOLv3.0 aimed to study solar-terrestrial interactions and climate changes. We implemented an interactive deposition scheme, &#160;based on gas tracers with and without nudging to the known meteorological fields. Production of 7Be was modelled using the 3D time-dependent Cosmic Ray induced Atmospheric Cascade (CRAC) model. The simulations were compared with the real concentrations (activity) and depositions measurements of 7Be in the air and water at Finnish stations. We have successfully reproduced and estimated the variability of the cosmogenic isotope 7Be produced by the galactic cosmic rays (GCR) on time scales longer than about a month, for the period of 2002&#8211;2008. The agreement between the modelled and measured data is very good (within 12%) providing a solid validation for the ability of the SOCOL CCM to reliably model production, transport, and deposition of cosmogenic isotopes, which is needed for precise studies of cosmic-ray variability in the past.&#160;

Download Full-text