On leaky-box approximation to GALPROP

Птускин, В. С.; Strelnikova, Olga; Свешникова, Л.

doi:10.1016/j.astropartphys.2009.02.004

Cited by 29 publications

(54 citation statements)

References 11 publications

(5 reference statements)

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“…Given that the CR spectrum observed at Earth has an energy dependence E −2.65 as derived from TRACER and CREAM data [9,37], in our calculations we used a slope of the diffusion coefficient δ = 2.65 − p in j , where for p in j we considered the values 2 and 2.31. In the first case, the diffusion coefficient has a slightly stronger energy dependence than the one used by [28] (E 0.6 ); in the other case, instead, we use the exact form given in that work. For the spallation cross section we adopt the simple formulation of Ref.…”

Section: Particle Spectrummentioning

confidence: 99%

“…In order to calculate the spectra of CRs at the Earth, an evaluation of the grammage is needed and we use the formulation of Ref. [28] as a starting point. Given that the CR spectrum observed at Earth has an energy dependence E −2.65 as derived from TRACER and CREAM data [9,37], in our calculations we used a slope of the diffusion coefficient δ = 2.65 − p in j , where for p in j we considered the values 2 and 2.31.…”

Section: Particle Spectrummentioning

confidence: 99%

See 1 more Smart Citation

On the cosmic ray spectrum from type II Supernovae expanding in their red giant presupernova wind

Cardillo¹,

Amato²,

Blasi³

2016

Proceedings of the 34th International Cosmic Ray Conference — PoS(ICRC2015)

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One of the most important challenges for the largely accepted idea that Galactic CRs are accelerated in SNR shocks is the maximum energy at which particles can be accelerated. The resonant streaming instability, long invoked for magnetic field amplification at shocks, can not provide sufficiently high fields and efficient enough scattering so as to ensure particle acceleration up to the knee. Here we discuss the non-resonant version of this instability which, with its faster growth and larger value of the amplified field, increases the achievable maximum energy. Because of their higher explosion rate, we focus on type II SNe expanding in their red supergiant wind and we find that the transition between Ejecta Dominated (ED) and Sedov-Taylor (ST) phases takes place at very early times. In this environment, the accelerated particle spectrum shows no high energy exponential cut-off but a spectral break at the maximum energy (E M ). Moreover, the maximum energy of protons can easily reach PeV energies. With this model, we tried to fit KASCADEGrande and ARGO -YBJ data but failed to find a parameter combination that can explain both data sets. We discuss the different scenarios implied by the two data sets.

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Section: Particle Spectrummentioning

confidence: 99%

Section: Particle Spectrummentioning

confidence: 99%

On the cosmic ray spectrum from type II Supernovae expanding in their red giant presupernova wind

Cardillo¹,

Amato²,

Blasi³

2016

Proceedings of the 34th International Cosmic Ray Conference — PoS(ICRC2015)

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“…Before energetic particles start affecting the environment, the diffusion coefficient is assumed to be the same as the Galactic average one, D g . Assuming a Kolmogorov's turbulence spectrum, we adopt for D g the analytical expression derived by [18] as a fit to GALPROP results within a leaky box model, i.e. D g (E) = 3.6 × 10 28 E 1/3 GeV cm 2 s −1 .…”

Section: Cr Propagation In the Vicinity Of The Sourcementioning

confidence: 99%

Contribution to diffuse gamma-ray emission coming from self-confined CRs around their Galactic sources

Morlino¹,

D'Angelo²,

Blasi³

et al. 2017

Proceedings of 35th International Cosmic Ray Conference — PoS(ICRC2017)

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Recent observations of the diffuse Galactic γ-ray emission by the Fermi-LAT satellite have shown significant deviations from models which assume the same diffusion properties for cosmic rays (CR) throughout the Galaxy. We explore the possibility that a fraction of this diffuse Galactic emission could be due to hadronic interactions of CRs self-confined in the region around their sources. In fact, freshly accelerated CRs that diffuse away from the acceleration region can trigger the streaming instability able to amplify magnetic disturbance and to reduce the particle diffusion. When this happen, CRs are trapped in the near source region for a time longer than expected and an extended γ-ray halo is produces around each source. Here we calculate the contribution to the diffuse γ-ray background due to the overlap along lines of sight of several of these extended halos. We find that if the density of neutrals is low, the halos can account for a substantial fraction of the diffuse emission observed by Fermi-LAT, depending on the orientation of the line of sight with respect to the direction of the galactic center.

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“…The escape length is determined from the relative abundance of secondary nuclei (primarily from the Boron-to-Carbon ratio) in cosmic rays. The approximation formula X e = 19β 3 g/cm 2 at R ≤ 3 GV and X e = 19β 3 (R/3GV) −0.6 g/cm 2 at R > 3 GV was given in Ptuskin et al (2009) (here R is the particle magnetic rigidity; β = v/c). According to the last equation, the resulting spectrum is steeper than the source spectrum by 0.6 at high enough energies, but the uncertainty in the last value is about 0.1, and statistically accurate measurements of the Boron-to-Carbon ratio are not available at energies above ∼ 30 GeV/nucleon.…”

Section: Spectra Of Cosmic Rays Produced By Supernova Remnantsmentioning

confidence: 99%

“…The leaky-box approximation to the diffusion model can be used for our purpose -the determination of proton and helium intensities, see Ptuskin et al (2009). The cosmic ray intensity obeys the relation I ∝ ν sn Q(X −1 e + σ/m a ) −1 , where X e is the escape length (the average matter thickness traversed by cosmic rays before they exit from the Galaxy), σ is the nuclear spallation cross section for a given type of relativistic nuclei moving through the interstellar gas, and m a is the mean interstellar atom mass.…”

Section: Spectra Of Cosmic Rays Produced By Supernova Remnantsmentioning

confidence: 99%

Spectra of Cosmic-Ray Protons and Helium Produced in Supernova Remnants

Птускин

Zirakashvili

Seo

2013

ApJ

111

105

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Data obtained in the ATIC-2 (Advanced Thin Ionization Calorimeter), CREAM (Cosmic Ray Energetics and Mass)) and PAMELA (Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics) experiments suggest that elemental interstellar spectra of cosmic rays below the knee at a few times 10 6 GeV are not simple power laws, but they experience hardening at magnetic rigidity above about 240 GV. Another essential feature is the difference between proton and Helium energy spectra, so that the He/p ratio increases by more than 50 % in the energy range from 10 2 to 10 4 GV. We consider the concavity of particle spectrum resulting from the nonlinear nature of diffusive shock acceleration in supernova remnants (SNR) as a possible reason for the observed spectrum hardening. Helium-to-proton ratio increasing with energy can be interpreted as a consequence of cosmic ray acceleration by forward and reverse shocks in SNRs.The contribution of particles accelerated by reverse shocks makes the concavity of the produced overall cosmic ray spectrum more pronounced. The spectra of protons and helium nuclei accelerated in SNRs and released into the interstellar medium are calculated. The derived steady state interstellar spectra are in reasonably good agreement with observations.

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On leaky-box approximation to GALPROP

Cited by 29 publications

References 11 publications

On the cosmic ray spectrum from type II Supernovae expanding in their red giant presupernova wind

On the cosmic ray spectrum from type II Supernovae expanding in their red giant presupernova wind

Contribution to diffuse gamma-ray emission coming from self-confined CRs around their Galactic sources

Spectra of Cosmic-Ray Protons and Helium Produced in Supernova Remnants

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