A study on the sharp knee and fine structures of cosmic ray spectra

Wang, Bo; Yuan, Qiang; Fan, Chao; Zhang, Jianli; Hu, Hongbo; Bi, Xiao-Jun

doi:10.1007/s11433-010-0194-y

Cited by 15 publications

(18 citation statements)

References 49 publications

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“…Hu et al [25] proposed a model to simultaneously explain the knee and the e + e − excess, incorporating pair production interactions between CRs and the ambient photon field. It was further shown that the irregular structures of the CR spectra around the knee region and the galactic 'B component' could also be well explained in this scenario [31]. As a consequence, one set of parameters in the mode of [25] also favors the single-source model.…”

Section: Origin Of the Kneementioning

confidence: 89%

On the Galactic Center being the main source of galactic cosmic rays as evidenced by recent cosmic ray and gamma ray observations

Guo¹,

Feng²,

Yuan³

et al. 2013

New J. Phys.

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We revisit the idea that the Galactic Center (GC) is the dominant source of galactic cosmic rays (GCRs), based on a series of new observational evidence. A unified model is proposed to explain the new phenomena of GCRs and γ-rays simultaneously. The GCRs are thought to be accelerated during past activities of the GC. The pair production process of GCRs in the strong radiation field due to the GC activity is responsible for the knee structure of the CR spectra. A fraction of e + e − produced by pair production interactions can be reaccelerated in the induced bipolar jets and be transported into the halo, leaving the Fermi γ-ray bubbles and WMAP microwave haze as the remnant signal. Finally, the CRs diffuse in the bulge could further interact with the interstellar medium to produce low energy e + e − . After cooling down, these positrons may annihilate to produce the 511 keV line emission as discovered by INTEGRAL.

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Section: Origin Of the Kneementioning

confidence: 89%

On the Galactic Center being the main source of galactic cosmic rays as evidenced by recent cosmic ray and gamma ray observations

Guo¹,

Feng²,

Yuan³

et al. 2013

New J. Phys.

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“…However, the energy spectrum after the interactions is not simply a broken power law or a power law with cutoff. Due to the detailed interaction energy losses, there is both a pile-up effect and a high-energy tail of the particle spectrum (Hu et al 2009;Wang et al 2010). It is worth noting that the KASCADE experiment recently reported a discovery of ankle-like spectrum for light elements at about 10 PeV (Antoni et al 2005).…”

Section: Composition Models In the Kneementioning

confidence: 99%

“…As for the physically based interaction model, the flux of individual nuclei depends on the energy loss rate and can not be analytically parameterized. We adopt the numerical results presented in Wang et al (2010) in the calculation.…”

Section: Composition Models In the Kneementioning

confidence: 99%

PINPOINTING THE KNEE OF COSMIC RAYS WITH DIFFUSE PEV Γ-Rays AND NEUTRINOS

Guo

Yuan

et al. 2014

ApJ

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The origin of the knee in the cosmic ray spectrum remains to be an unsolved fundamental problem. There are various kinds of models that predict different break positions and the compositions of the knee. In this work, we suggest the use of diffuse γ-rays and neutrinos as probes to test these models. Based on several typical types of composition models, the diffuse γ-ray and neutrino spectra are calculated and show distinctive cutoff behaviors at energies from tens of TeV to multi-PeV. The expected flux will be observable by the newly upgraded Tibet-ASγ+MD (muon detector) experiment as well as more sensitive future projects, such as LHAASO and HiSCORE. By comparing the neutrino spectrum with the recent observations by the IceCube experiment, we find that the diffuse neutrinos from interactions between the cosmic rays and the interstellar medium may not be responsible to the majority of the IceCube events. Future measurements of the neutrinos may be able to identify the Galactic diffuse component and shed further light on the problem of the knee of cosmic rays.

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“…Photodisintegration of the CR nuclei by interactions with optical and soft UV photons in the source region has also been considered (Karakula & Tkacsyk 2004;Candia et al 2002), but it does not succeed in describing the composition in the direct measurements realm and at the highest energies, as shown in Fig.26 (bottom right). A more recent proposal relates the knee to the e + e − pair production by CR nuclei interacting with background photons (Wang et al 2010). Finally, new hadronic interactions could take place in the atmosphere at very high energies.…”

Section: Models For the Kneementioning

confidence: 99%

Astrophysics of Galactic Charged Cosmic Rays

Castellina¹,

Donato²

2013

Planets, Stars and Stellar Systems

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A review is given of the main properties of the charged component of galactic cosmic rays, particles detected at Earth with an energy spanning from tens of MeV up to about 10 19 eV. After a short introduction to the topic and an historical overview, the properties of cosmic rays are discussed with respect to different energy ranges. The origin and the propagation of nuclei in the Galaxy are dealt with from a theoretical point of view. The mechanisms leading to the acceleration of nuclei by supernova remnants and to their subsequent diffusion through the inhomogeneities of the galactic magnetic field are discussed and some clue is given on the predictions and observations of fluxes of antimatter, both from astrophysical sources and from dark matter annihilation in the galactic halo. The experimental techniques and instrumentations employed for the detection of cosmic rays at Earth are described. Direct methods are viable up to 10 14 eV, by means of experiments flown on balloons or satellites, while above that energy, due to their very low flux, cosmic rays can be studied only indirectly by exploiting the particle cascades they produce in the atmosphere. The possible physical interpretation of the peculiar features observed in the energy spectrum of galactic cosmic rays, and in particular the so-called "knee" at about 4×10 15 eV, are discussed. A section is devoted to the region between about 10 18 and 10 19 eV, which is believed to host the transition between galactic and extragalactic cosmic rays. The conclusion gives some perspectives on the cosmic ray astrophysics field. Thanks to a wealth of different experiments, this research area is living a very flourishing era. The activity is exciting both from the theoretical and the instrumental sides, and its interconnection with astronomy, astrophysics and particle physics experiences non-stop growth.

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A study on the sharp knee and fine structures of cosmic ray spectra

Cited by 15 publications

References 49 publications

On the Galactic Center being the main source of galactic cosmic rays as evidenced by recent cosmic ray and gamma ray observations

On the Galactic Center being the main source of galactic cosmic rays as evidenced by recent cosmic ray and gamma ray observations

PINPOINTING THE KNEE OF COSMIC RAYS WITH DIFFUSE PEV Γ-Rays AND NEUTRINOS

Astrophysics of Galactic Charged Cosmic Rays

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