Linked Life Data

12673244

Source:http://linkedlifedata.com/resource/pubmed/id/12673244

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6931
pubmed:dateCreated
2003-4-3
pubmed:abstractText
The H3+ molecular ion plays a fundamental role in interstellar chemistry, as it initiates a network of chemical reactions that produce many molecules. In dense interstellar clouds, the H3+ abundance is understood using a simple chemical model, from which observations of H3+ yield valuable estimates of cloud path length, density and temperature. But observations of diffuse clouds have suggested that H3+ is considerably more abundant than expected from the chemical models. Models of diffuse clouds have, however, been hampered by the uncertain values of three key parameters: the rate of H3+ destruction by electrons (e-), the electron fraction, and the cosmic-ray ionization rate. Here we report a direct experimental measurement of the H3+ destruction rate under nearly interstellar conditions. We also report the observation of H3+ in a diffuse cloud (towards Persei) where the electron fraction is already known. From these, we find that the cosmic-ray ionization rate along this line of sight is 40 times faster than previously assumed. If such a high cosmic-ray flux is ubiquitous in diffuse clouds, the discrepancy between chemical models and the previous observations of H3+ can be resolved.
pubmed:language
eng
pubmed:journal
pubmed:status
PubMed-not-MEDLINE
pubmed:month
Apr
pubmed:issn
0028-0836
pubmed:author
pubmed:issnType
Print
pubmed:day
3
pubmed:volume
422
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
500-2
pubmed:dateRevised
2003-11-4
pubmed:year
2003
pubmed:articleTitle
An enhanced cosmic-ray flux towards zeta Persei inferred from a laboratory study of the H3+-e- recombination rate.
pubmed:affiliation
Department of Chemistry, Department of Astronomy, University of California at Berkeley, Berkeley, California 94720, USA. bjmccall@astro.berkeley.edu
pubmed:publicationType
Journal Article