TY - JOUR
T1 - Acceleration and escape of first cosmic rays
AU - Ohira, Yutaka
AU - Murase, Kohta
N1 - Funding Information:
This work is supported by JSPS KAKENHI Grant Number JP16K17702 (Y.O.), JP19H01893(Y.O.) and Alfred P. Sloan Foundation and NSF Grant No. PHY-1620777 (K.M.). Y.O. is supported by MEXT/JSPS Leading Initiative for Excellent Young Researchers.
Funding Information:
control of the various efficiency parameters but are working to improve them. We would like to thank Matthew Collins, Forest Martinez-Mckinney, and Yang Zhou for their help in the design, construction and integration of the instrument. We thank Chris Field and the CSBF for their support during the integration period in Palestine, Texas, and for the successful balloon flight. We thank Esrange for their support during the flight campaign. This work is supported by the NASA award 80NSSC19K0746.
Publisher Copyright:
© Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND 4.0)
PY - 2021/7/2
Y1 - 2021/7/2
N2 - There are cosmic rays in the current universe. They play various important roles in the current universe. However, we do not understand when, where, how cosmic rays are first accelerated since the Big Bang. We show that supernova remnants of first stars can accelerate the first cosmic rays at z ≈ 20. Shock waves of the first supernova remnants are nonrelativistic Weibel mediated shock, so that the coherent length scale of magnetic field fluctuations is much smaller than the gyroradius of the accelerated particles. Therefore, the maximum energy of the first CRs becomes much smaller than that in the current universe, which is about 100 MeV. Furthermore, we discuss cosmic-ray acceleration by accretion shocks due to the cosmological structure formation at z ≈ 20. Since the accretion shocks at z ≈ 20 propagate not an ionized medium but a neutral medium, they cannot accelerate the first cosmic rays.
AB - There are cosmic rays in the current universe. They play various important roles in the current universe. However, we do not understand when, where, how cosmic rays are first accelerated since the Big Bang. We show that supernova remnants of first stars can accelerate the first cosmic rays at z ≈ 20. Shock waves of the first supernova remnants are nonrelativistic Weibel mediated shock, so that the coherent length scale of magnetic field fluctuations is much smaller than the gyroradius of the accelerated particles. Therefore, the maximum energy of the first CRs becomes much smaller than that in the current universe, which is about 100 MeV. Furthermore, we discuss cosmic-ray acceleration by accretion shocks due to the cosmological structure formation at z ≈ 20. Since the accretion shocks at z ≈ 20 propagate not an ionized medium but a neutral medium, they cannot accelerate the first cosmic rays.
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M3 - Conference article
AN - SCOPUS:85127526073
SN - 1824-8039
VL - 358
JO - Proceedings of Science
JF - Proceedings of Science
M1 - 116
T2 - 36th International Cosmic Ray Conference, ICRC 2019
Y2 - 24 July 2019 through 1 August 2019
ER -