TY - JOUR
T1 - High-energy cosmic ray nuclei from tidal disruption events
T2 - Origin, survival, and implications
AU - Zhang, B. Theodore
AU - Murase, Kohta
AU - Oikonomou, Foteini
AU - Li, Zhuo
N1 - Funding Information:
We thank Shigeo S. Kimura and Kumiko Kotera for helpful discussions. The work of K. M. is supported by Alfred P. Sloan Foundation and the U.S. National Science Foundation (NSF) under grants NSF Grant No. PHY-1620777. It is partially supported by the National Natural Science Foundation of China under Grant No. 11273005 and the National Basic Research Program (973 Program) of China under Grant No. 2014CB845800 (Z. L.). B. T. Z. is supported by the China Scholarship Council (CSC) to conduct research at Penn State University (PSU).
Publisher Copyright:
© 2017 American Physical Society.
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2017/9/13
Y1 - 2017/9/13
N2 - Tidal disruption events (TDEs) by supermassive or intermediate mass black holes have been suggested as candidate sources of ultrahigh-energy cosmic rays (UHECRs) and high-energy neutrinos. Motivated by the recent measurements from the Pierre Auger Observatory, which indicates a metal-rich cosmic-ray composition at ultrahigh energies, we investigate the fate of UHECR nuclei loaded in TDE jets. First, we consider the production and survival of UHECR nuclei at internal shocks, external forward and reverse shocks, and nonrelativistic winds. Based on the observations of Swift J1644+57, we show that the UHECRs can survive for external reverse and forward shocks, and disk winds. On the other hand, UHECR nuclei are significantly disintegrated in internal shocks, although they could survive for low-luminosity TDE jets. Assuming that UHECR nuclei can survive, we consider implications of different composition models of TDEs. We find that the tidal disruption of main sequence stars or carbon-oxygen white dwarfs does not successfully reproduce UHECR observations, namely the observed composition or spectrum. The observed mean depth of the shower maximum and its deviation could be explained by oxygen-neon-magnesium white dwarfs, although they may be too rare to be the sources of UHECRs.
AB - Tidal disruption events (TDEs) by supermassive or intermediate mass black holes have been suggested as candidate sources of ultrahigh-energy cosmic rays (UHECRs) and high-energy neutrinos. Motivated by the recent measurements from the Pierre Auger Observatory, which indicates a metal-rich cosmic-ray composition at ultrahigh energies, we investigate the fate of UHECR nuclei loaded in TDE jets. First, we consider the production and survival of UHECR nuclei at internal shocks, external forward and reverse shocks, and nonrelativistic winds. Based on the observations of Swift J1644+57, we show that the UHECRs can survive for external reverse and forward shocks, and disk winds. On the other hand, UHECR nuclei are significantly disintegrated in internal shocks, although they could survive for low-luminosity TDE jets. Assuming that UHECR nuclei can survive, we consider implications of different composition models of TDEs. We find that the tidal disruption of main sequence stars or carbon-oxygen white dwarfs does not successfully reproduce UHECR observations, namely the observed composition or spectrum. The observed mean depth of the shower maximum and its deviation could be explained by oxygen-neon-magnesium white dwarfs, although they may be too rare to be the sources of UHECRs.
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U2 - 10.1103/PhysRevD.96.063007
DO - 10.1103/PhysRevD.96.063007
M3 - Article
AN - SCOPUS:85031718777
VL - 96
JO - Physical Review D
JF - Physical Review D
SN - 2470-0010
IS - 6
M1 - 063007
ER -