Cosmogenic Neutrinos Challenge the Cosmic Ray Proton Dip Model
Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
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Cosmogenic Neutrinos Challenge the Cosmic Ray Proton Dip Model. / Heinze, Jonas; Boncioli, Denise; Bustamante, Mauricio; Winter, Walter.
I: The Astrophysical Journal, Bind 825, Nr. 2, 122, 11.07.2016.Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
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TY - JOUR
T1 - Cosmogenic Neutrinos Challenge the Cosmic Ray Proton Dip Model
AU - Heinze, Jonas
AU - Boncioli, Denise
AU - Bustamante, Mauricio
AU - Winter, Walter
N1 - published in Apj; 15 pages, 12 figures
PY - 2016/7/11
Y1 - 2016/7/11
N2 - The origin and composition of ultra-high-energy cosmic rays (UHECRs) remain a mystery. The proton dip model describes their spectral shape in the energy range above $10^9$ GeV by pair production and photohadronic interactions with the cosmic microwave background. The photohadronic interactions also produce cosmogenic neutrinos peaking around $10^9$ GeV. We test whether this model is still viable in light of recent UHECR spectrum measurements from the Telescope Array experiment, and upper limits on the cosmogenic neutrino flux from IceCube. While two-parameter fits have been already presented, we perform a full scan of the three main physical model parameters: source redshift evolution, injected proton maximal energy, and spectral index. We find qualitatively different conclusions compared to earlier two-parameter fits in the literature: a mild preference for a maximal energy cutoff at the sources instead of the Greisen--Zatsepin--Kuzmin (GZK) cutoff, hard injection spectra, and strong source evolution. The predicted cosmogenic neutrino flux exceeds the IceCube limit for any parameter combination. As a result, the proton dip model is challenged at more than 95\% C.L. This is strong evidence against this model independent of mass composition measurements.
AB - The origin and composition of ultra-high-energy cosmic rays (UHECRs) remain a mystery. The proton dip model describes their spectral shape in the energy range above $10^9$ GeV by pair production and photohadronic interactions with the cosmic microwave background. The photohadronic interactions also produce cosmogenic neutrinos peaking around $10^9$ GeV. We test whether this model is still viable in light of recent UHECR spectrum measurements from the Telescope Array experiment, and upper limits on the cosmogenic neutrino flux from IceCube. While two-parameter fits have been already presented, we perform a full scan of the three main physical model parameters: source redshift evolution, injected proton maximal energy, and spectral index. We find qualitatively different conclusions compared to earlier two-parameter fits in the literature: a mild preference for a maximal energy cutoff at the sources instead of the Greisen--Zatsepin--Kuzmin (GZK) cutoff, hard injection spectra, and strong source evolution. The predicted cosmogenic neutrino flux exceeds the IceCube limit for any parameter combination. As a result, the proton dip model is challenged at more than 95\% C.L. This is strong evidence against this model independent of mass composition measurements.
KW - astro-ph.HE
U2 - 10.3847/0004-637X/825/2/122
DO - 10.3847/0004-637X/825/2/122
M3 - Journal article
VL - 825
JO - Astrophysical Journal
JF - Astrophysical Journal
SN - 0004-637X
IS - 2
M1 - 122
ER -
ID: 184745777