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Shock processing of interstellar grainsShock processing plays an important role in the life of a typical interstellar grain. Shocks of 100 km/s-l or greater can destroy about 50% of the grain material under appropriate preshock conditions of density and magnetic field. The destruction occurs by grain-grain collisions and nonthermal sputtering for steady state radiative shocks and by thermal sputtering for fast adiabatic shocks. The evaluation of the lifetime of grains against shock destruction depends on models of the interstellar medium (ISM) structure and on supernova remnants (SNR) evolution. Results from various authors give lifetimes between 10 to the 8th and 10 to the 9th power years, compared to typical injection times for new grains of a few times 10 to the 9th power years. These numbers require that a major portion of the interstellar silicon bearing grain material must be formed by grain growth in the ISM. At the same time, the presence of isotopic anomalies in some meteorites implies that at least some grains must survive from their formation in SNRs or red giant winds through incorporation into the solar system.
Document ID
19860014026
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Seab, C. G. (NASA Ames Research Center Moffett Field, CA, United States)
Shull, J. M. (Colorado Univ. Boulder, United States)
Date Acquired
August 12, 2013
Publication Date
January 1, 1986
Publication Information
Publication: NASA, Washington. Interrelationships among Circumstellar, Interstellar and Interplanetary Dust
Subject Category
Astrophysics
Accession Number
86N23497
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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IDRelationTitle19860014022Collected WorksInterrelationships among Circumstellar, Interstellar and Interplanetary Dust
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