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A new limit on the time between the nucleosynthesis and the acceleration of cosmic rays in supernova remnants using the Co/Ni ratioUsing new cross section measurements of Ni into Co, data on the Co/Ni ratio in cosmic rays from the HEAO C spacecraft have been reinterpreted in terms of the time between nucleosynthesis and the acceleration of cosmic rays, delta t. The observed Co/Ni ratio is now consistent with interstellar fragmentation only, leading to a small or zero source abundance. In terms of the decay of e-process nucleosynthesis nuclides into Co after a supernova explosion, this permits an estimate of delta t = 4-30,000 yr for the time between nucleosynthesis and the acceleration of cosmic rays if supernovae are the direct progenitors of cosmic rays. These age limits are used in conjunction with models of the expansion of supernova remnants (SNRs), to estimate that cosmic rays are accelerated when the radius of these remnants is between 0.1 and 25 pc.
Document ID
19900034018
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Webber, W. R.
(New Hampshire Univ. Durham, NH, United States)
Gupta, M.
(New Hampshire, University Durham, United States)
Date Acquired
August 14, 2013
Publication Date
January 10, 1990
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 348
ISSN: 0004-637X
Subject Category
Astrophysics
Accession Number
90A21073
Funding Number(s)
CONTRACT_GRANT: NGR-30-002-052
Distribution Limits
Public
Copyright
Other

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