Publication Date:
2011-03-10
Description:
Protons and helium nuclei are the most abundant components of the cosmic radiation. Precise measurements of their fluxes are needed to understand the acceleration and subsequent propagation of cosmic rays in our Galaxy. We report precision measurements of the proton and helium spectra in the rigidity range 1 gigavolt to 1.2 teravolts performed by the satellite-borne experiment PAMELA (payload for antimatter matter exploration and light-nuclei astrophysics). We find that the spectral shapes of these two species are different and cannot be described well by a single power law. These data challenge the current paradigm of cosmic-ray acceleration in supernova remnants followed by diffusive propagation in the Galaxy. More complex processes of acceleration and propagation of cosmic rays are required to explain the spectral structures observed in our data.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Adriani, O -- Barbarino, G C -- Bazilevskaya, G A -- Bellotti, R -- Boezio, M -- Bogomolov, E A -- Bonechi, L -- Bongi, M -- Bonvicini, V -- Borisov, S -- Bottai, S -- Bruno, A -- Cafagna, F -- Campana, D -- Carbone, R -- Carlson, P -- Casolino, M -- Castellini, G -- Consiglio, L -- De Pascale, M P -- De Santis, C -- De Simone, N -- Di Felice, V -- Galper, A M -- Gillard, W -- Grishantseva, L -- Jerse, G -- Karelin, A V -- Koldashov, S V -- Krutkov, S Y -- Kvashnin, A N -- Leonov, A -- Malakhov, V -- Malvezzi, V -- Marcelli, L -- Mayorov, A G -- Menn, W -- Mikhailov, V V -- Mocchiutti, E -- Monaco, A -- Mori, N -- Nikonov, N -- Osteria, G -- Palma, F -- Papini, P -- Pearce, M -- Picozza, P -- Pizzolotto, C -- Ricci, M -- Ricciarini, S B -- Rossetto, L -- Sarkar, R -- Simon, M -- Sparvoli, R -- Spillantini, P -- Stozhkov, Y I -- Vacchi, A -- Vannuccini, E -- Vasilyev, G -- Voronov, S A -- Yurkin, Y T -- Wu, J -- Zampa, G -- Zampa, N -- Zverev, V G -- New York, N.Y. -- Science. 2011 Apr 1;332(6025):69-72. doi: 10.1126/science.1199172. Epub 2011 Mar 3.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Physics, University of Florence, I-50019 Sesto Fiorentino, Florence, Italy.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21385721" target="_blank"〉PubMed〈/a〉
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
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Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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