Elemental energy spectra of cosmic rays from the data of the ATIC-2 experiment

Панов, А. Д.; Adams, J. H.; Ahn, H. S.; Batkov, K. E.; Bashindzhagyan, G. L.; Watts, J. W.; Wefel, J. P.; Wu, Jian; Ganel, O.; Guzik, T. G.; Gunashingha, R. M.; Zatsepin, V. I.; Isbert, J.; Kim, K. C.; Christl, M. J.; Kouznetsov, E. N.; Panasyuk, M. I.; Seo, E. S.; Sokolskaya, N. V.; Chang, Jin; Schmidt, Wolfgang; Fazely, A. R.

doi:10.3103/s1062873807040168

Cited by 114 publications

(109 citation statements)

References 9 publications

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“…Most recently the satellite experiment Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA) reported the precise measurement about the proton and Helium spectra with rigidity from GV to 1.2 TV [3]. PAMELA data show clearly that the proton and Helium spectra deviate from the single power-law function above ∼ 30 GV with a hardening at rigidity ∼ 200 GV, which is basically consistent with the results of CREAM and the previous Advanced Thin Ionization Calorimeter (ATIC-2) [4]. The hardening of the CR spectra challenges the traditional CR acceleration and propagation paradigm.…”

supporting

confidence: 84%

“…The solid line in each panel represents a sub-exponential cutoff behavior of the high energy spectra around the knee region, while the dashed line is for broken power-law type. References of the data are-proton: ATIC-2 [4], PAMELA [3], CREAM [2], Tibet [30], KASCADE [31]; Helium: ATIC-2 [4], PAMELA [3], CREAM [2], Tibet-BD [32], KASCADE [31]; Carbon: HEAO3 [33], CREAM [1]; Oxygen: HEAO3 [33], CREAM [1]; Iron: CRN [34], RUNJOB [35], SOKOL [36], JACEE [37], TRACER [38], HEAO3 [33], CREAM [1]; all-particle: Tibet-III [39]. The normalized all-particle data are derived by combining all data with a rescale based on the extrapolation of the direct measurements [26].…”

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confidence: 99%

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Cosmic ray spectral hardening due to dispersion in the source injection spectra

Yuan

Zhang

2011

Phys. Rev. D

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Recent cosmic ray (CR) experiments discovered that the CR spectra experience a remarkable hardening for rigidity above several hundred GV. We propose that this is caused by the superposition of the CR energy spectra of many sources that have a dispersion in the injection spectral indices. Adopting similar parameters as those of supernova remnants derived from the Fermi γ-ray observations, we can reproduce the observational CR spectra of different species well. This may be interpreted as evidence to support the supernova remnant origin of CRs below the knee. We further propose that the same mechanism may explain the "ankle" of the ultra high energy CR spectrum.PACS numbers: 98.70. Sa,96.50.sb,98.38.Mz Introduction-Nearly 100 years after the discovery of cosmic rays by V. Hess in 1912, several basic questions on CRs, such as the source(s) and the propagation effects, are still not well understood. Precise measurements of the CR spectra and observations of high energy γ-rays and neutrinos, are of great importance to approach the answers to these fundamental questions.

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supporting

confidence: 84%

mentioning

confidence: 99%

Cosmic ray spectral hardening due to dispersion in the source injection spectra

Yuan

Zhang

2011

Phys. Rev. D

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“…5. The solid line represents our results, and the data are taken from CREAM (Ahn et al 2009), ATIC (Panov et al 2007), CRN (Müller et al 1991;Swordy et al 1990), HEAO (Engelmann et al 1990), and TRACER (Obermeier et al 2011). The carbon and oxygen source parameters used are (q C = 2.24, f C = 0.024%), and (q O = 2.26, f O = 0.025%) respectively, where the f 's are given in units of 10 51 ergs.…”

Section: Comparison With the Datamentioning

confidence: 99%

“…6, where the top panel represents proton and the bottom panel represents helium. The lines represent our results, and the data are taken from the CREAM (Yoon et al 2011), ATIC (Panov et al 2007), AMS-01 (Alcaraz et al 2000;Aguilar et al 2002), and PAMELA (Adriani et al 2011) experiments. The source parameters used are (q p = 2.21, f p = 6.95%) for protons, and (q He = 2.18, f He = 0.79%) for helium, and we use the same solar modulation parameter as given above.…”

Section: Comparison With the Datamentioning

confidence: 99%

“…Measurements of cosmic rays by the Advanced Thin Ionization Calorimeter (ATIC; Panov et al 2007), Cosmic Ray Energetics and Mass (CREAM; Yoon et al 2011), and Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA; Adriani et al 2011) experiments have found a spectral anomaly at GeV-TeV energies. The spectrum in the TeV region is found to be harder than at GeV energies.…”

Section: Introductionmentioning

confidence: 99%

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GeV-TeV cosmic-ray spectral anomaly as due to reacceleration by weak shocks in the Galaxy

Thoudam

Hörandel

2014

A&A

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Recent cosmic-ray measurements have found an anomaly in the cosmic-ray energy spectrum at GeV-TeV energies. Although the origin of the anomaly is not clearly understood, suggested explanations include the effect of cosmic-ray source spectrum, propagation effects, and the effect of nearby sources. In this paper, we propose that the spectral anomaly might be an effect of reacceleration of cosmic rays by weak shocks in the Galaxy. After acceleration by strong supernova remnant shock waves, cosmic rays undergo diffusive propagation through the Galaxy. During the propagation, cosmic rays may again encounter expanding supernova remnant shock waves, and get re-accelerated. As the probability of encountering old supernova remnants is expected to be larger than the younger remnants because of their bigger sizes, reacceleration is expected to be produced mainly by weaker shocks. Since weaker shocks generate a softer particle spectrum, the resulting re-accelerated component will have a spectrum steeper than the initial cosmic-ray source spectrum produced by strong shocks. For a reasonable set of model parameters, it is shown that the re-accelerated component can dominate the GeV energy region while the non-reaccelerated component dominates at higher energies, thereby explaining the observed GeV-TeV spectral anomaly.

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