Stochastic Fluctuations of Low-Energy Cosmic Rays and the Interpretation of Voyager Data
| Autor: | Philipp Mertsch, Florian Schulze, Sarah Recchia, Vo Hong Minh Phan, Stefano Gabici |
|---|---|
| Přispěvatelé: | AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP) |
| Rok vydání: | 2021 |
| Předmět: |
electron
Spectral shape analysis Proton fluctuation: stochastic General Physics and Astronomy FOS: Physical sciences Cosmic ray Astrophysics Expectation value Electron GeV 01 natural sciences 0103 physical sciences Range (statistics) AMS Diffusion (business) 010303 astronomy & astrophysics model: discrete [PHYS]Physics [physics] High Energy Astrophysical Phenomena (astro-ph.HE) Physics 010308 nuclear & particles physics diffusion Statistical model model: statistical cosmic radiation spectral [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] Astrophysics - High Energy Astrophysical Phenomena |
| Zdroj: | Phys.Rev.Lett. Phys.Rev.Lett., 2021, 127 (14), pp.141101. ⟨10.1103/PhysRevLett.127.141101⟩ Proceedings of Science 395, 0165 (2022). doi:10.22323/1.395.0165 special issue: "37th International Cosmic Ray Conference : ICRC2021 : 12-23 July 2021 : Berlin, Germany-Online / Editorial Board: Alexander Kappes, Bianca Keilhauer" 37. International Cosmic Ray Conference, IRC 2021, online, 2021-07-12-2021-07-23 Physical Review Letters Physical Review Letters, American Physical Society, 2021, 127 (14), pp.141101. ⟨10.1103/PhysRevLett.127.141101⟩ |
| ISSN: | 0031-9007 1079-7114 |
| DOI: | 10.22323/1.395.0165 |
| Popis: | Data from the Voyager probes have provided us with the first measurement of cosmic ray intensities at MeV energies, an energy range which had previously not been explored. Simple extrapolations of models that fit data at GeV energies, e.g. from AMS-02, however, fail to reproduce the Voyager data in that the predicted intensities are too high. Oftentimes, this discrepancy is addressed by adding a break to the source spectrum or the diffusion coefficient in an ad hoc fashion, with a convincing physical explanation yet to be provided. Here, we argue that the discrete nature of cosmic ray sources, which is usually ignored, is instead a more likely explanation. We model the distribution of intensities expected from a statistical model of discrete sources and show that its expectation value is not representative, but has a spectral shape different from that for a typical configuration of sources. The Voyager proton and electron data are however compatible with the median of the intensity distribution. We stress that this model can explain the Voyager data without requiring any unphysical breaks. Comment: 6 pages and 3 figures (supplemental material added) |
| Databáze: | OpenAIRE |
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