TY - JOUR
T1 - Super-knee Cosmic Rays from Galactic Neutron Star Merger Remnants
AU - Kimura, Shigeo S.
AU - Murase, Kohta
AU - Mészáros, Peter
N1 - Funding Information:
S.S.K. thanks Susumu Inoue for the useful discussion at the ASJ annual meeting in 2018 March. We are grateful to Kunihito Ioka for helpful comments and Ke Fang for providing the data. This work is supported by JSPS Oversea Research Fellowship, the IGC post-doctoral fellowship program (S.S.K.), Alfred P. Sloan Foundation, NSF grant No. PHY-1620777 (K.M.), and NASA NNX13AH50G (P.M.). While we were finalizing this project, we became aware of a related but independent work by Rodrigues et al. (arXiv:1806.01624).
Publisher Copyright:
© 2018. The American Astronomical Society. All rights reserved..
PY - 2018/10/10
Y1 - 2018/10/10
N2 - The detection of gravitational waves and electromagnetic counterparts from a binary neutron star merger confirmed that it is accompanied by the launch of fast merger ejecta. Analogous to supernova remnants, forward shocks formed by the interaction of the ejecta with interstellar material will produce high-energy cosmic rays. We investigate the possibility that Galactic neutron star merger remnants (NSMRs) significantly contribute to the observed cosmic rays in the energy range between the knee and the ankle. Using typical parameters obtained by the modeling of GW170817, we find that NSMRs can accelerate iron nuclei up to ∼500 PeV. We calculate the cosmic-ray (CR) spectrum and composition observed on Earth, and show that the Galactic NSMR scenario can account for the experimental CR data in the 20-1000 PeV range. Our model can naturally explain the hardening feature around 20 PeV for the total CR spectrum, which has been observed by the Telescope Array Low Energy extension and the IceTop air-shower array.
AB - The detection of gravitational waves and electromagnetic counterparts from a binary neutron star merger confirmed that it is accompanied by the launch of fast merger ejecta. Analogous to supernova remnants, forward shocks formed by the interaction of the ejecta with interstellar material will produce high-energy cosmic rays. We investigate the possibility that Galactic neutron star merger remnants (NSMRs) significantly contribute to the observed cosmic rays in the energy range between the knee and the ankle. Using typical parameters obtained by the modeling of GW170817, we find that NSMRs can accelerate iron nuclei up to ∼500 PeV. We calculate the cosmic-ray (CR) spectrum and composition observed on Earth, and show that the Galactic NSMR scenario can account for the experimental CR data in the 20-1000 PeV range. Our model can naturally explain the hardening feature around 20 PeV for the total CR spectrum, which has been observed by the Telescope Array Low Energy extension and the IceTop air-shower array.
KW - acceleration of particles
KW - astroparticle physics
KW - cosmic rays
KW - gravitational waves
KW - ISM: supernova remnants
KW - stars: neutron
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U2 - 10.3847/1538-4357/aadc0a
DO - 10.3847/1538-4357/aadc0a
M3 - Article
AN - SCOPUS:85055277802
SN - 0004-637X
VL - 866
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1
M1 - 51
ER -