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Beryllium and boron constraints on an early Galactic bright phaseThe recent observations of Be and B in metal-deficient halo dwarfs are used to constrain a 'bright phase' of enhanced cosmic-ray flux in the early Galaxy. Assuming that this Be and B arises from cosmic-ray spallation in the early Galaxy, limits are placed on the intensity of the early (Population II) cosmic-ray flux relative to the present (Population I) flux. A simple estimate of bounds on the flux ratio is 1 - 40. This upper bound would restrict galaxies like our own from producing neutrino fluxes that would be detectable in any currently proposed detectors. It is found that the relative enhancement of the early flux varies inversely with the relative time of enhancement. It is noted that associated gamma-ray production via pp - pi sup 0 pp may be a significant contribution to the gamma-ray background above 100 MeV.
Document ID
19930046719
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Fields, Brian D.
(NASA Headquarters Washington, DC United States)
Schramm, David N.
(Chicago Univ.; NASA/Fermilab. Astrophysics Center Batavia, IL, United States)
Truran, James W.
(Chicago Univ. IL, United States)
Date Acquired
August 16, 2013
Publication Date
March 10, 1993
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 405
Issue: 2
ISSN: 0004-637X
Subject Category
Astrophysics
Accession Number
93A30716
Funding Number(s)
CONTRACT_GRANT: NAGW-1821
CONTRACT_GRANT: DE-FG02-91ER-40606
CONTRACT_GRANT: NAGW-2421
CONTRACT_GRANT: NSF AST-90-22629
CONTRACT_GRANT: NAGW-2381
CONTRACT_GRANT: NAG5-1565
CONTRACT_GRANT: NSF AST-89-17442
Distribution Limits
Public
Copyright
Other

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