THE UNREASONABLE WEAKNESS OF R -PROCESS COSMIC RAYS IN THE NEUTRON-STAR-MERGER NUCLEOSYNTHESIS SCENARIO

Journal Article · Wed Aug 10 00:00:00 EDT 2016 · Astrophysical Journal

DOI:https://doi.org/10.3847/0004-637X/827/1/83· OSTI ID:22679518

Kyutoku, Koutarou ^[1]; Ioka, Kunihito ^[2]

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1. Interdisciplinary Theoretical Science (iTHES) Research Group, RIKEN, Wako, Saitama 351-0198 (Japan)
2. Center for Gravitational Physics, Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto, 606-8502 (Japan)

We reach the robust conclusion that, by combining the observed cosmic rays of r -process elements with the fact that the velocity of the neutron-star-merger ejecta is much higher than that of the supernova ejecta, either (1) the reverse shock in the neutron-star-merger ejecta is a very inefficient accelerator that converts less than 0.003% of the ejecta kinetic energy to the cosmic-ray energy or (2) the neutron star merger is not the origin of the Galactic r -process elements. We also find that the acceleration efficiency should be less than 0.1% for the reverse shock of the supernova ejecta with observed cosmic rays lighter than the iron.

• OSTI ID: 22679518
• Journal Information: Astrophysical Journal, Vol. 827, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ACCELERATION
ACCELERATORS
COSMIC RADIATION
EFFICIENCY
ELEMENT ABUNDANCE
IRON
KINETIC ENERGY
NEUTRON STARS
NUCLEAR REACTIONS
NUCLEOSYNTHESIS
R PROCESS
SHOCK WAVES
SUPERNOVA REMNANTS
VELOCITY