Sign on

SAO/NASA ADS Astronomy Abstract Service

· Find Similar Abstracts (with default settings below)
· Full Refereed Journal Article (PDF/Postscript)
· Full Refereed Scanned Article (GIF)
· References in the article
· Citations to the Article (93) (Citation History)
· Refereed Citations to the Article
· SIMBAD Objects (2)
· Reads History
·
· Translate This Page
Title:
Galactic evolution of D and He-3
Authors:
Galli, Daniele; Palla, Francesco; Ferrini, Federico; Penco, Umberto
Affiliation:
AA(Osservatorio Astrofisico di Arcetri, Firenze, Italy), AB(Osservatorio Astrofisico di Arcetri, Firenze, Italy), AC(Università di Pisa, Pisa, Italy), AD(Università di Pisa, Pisa, Italy)
Publication:
Astrophysical Journal, Part 1 (ISSN 0004-637X), vol. 443, no. 2, p. 536-550 (ApJ Homepage)
Publication Date:
04/1995
Category:
Astrophysics
Origin:
STI
NASA/STI Keywords:
ABUNDANCE, BIG BANG COSMOLOGY, CHEMICAL EVOLUTION, DEUTERIUM, GALACTIC EVOLUTION, HELIUM ISOTOPES, NUCLEAR FUSION, STELLAR MODELS, BARYONS, H II REGIONS, INTERSTELLAR MATTER, NOVAE, PHOTONS, SOLAR NEUTRINOS
DOI:
10.1086/175546
Bibliographic Code:
1995ApJ...443..536G

Abstract

The evolution of D and He-3 is considered in the framework of a consistent model for the chemical evolution of the Galaxy. The destruction of D in the course of galactic evolution is found to be modest, of the order of a factor of approximately 2; the good agreement found with the observed abundance of D in the presolar material and in the interstellar medium makes it possible to derive narrow constraints on the primordial D, or, equivalently, on the allowed range of the baryon-to-photon ratio eta according to standard big-bang nucleosynthesis. Conversely, the evolution of He-3 remains one of the major problems in the field of chemical galactic evolution: results based on the predictions of updated stellar models are shown to lead to an overproduction of He-3 by a factor of approximately 5-7 at the time of formation of the Sun, and by a factor of approximately 5-20 with respect to measured abundances in galactic H II regions. Several possibilities to reduce this discrepancy are presented and discussed quantitatively; none of them is found to produce the desired result, with the exception of a hypothetical low-energy resonance in the cross section of the He-3 (He-3, 2p) He-4 reaction, advocated also as a possible solution to the solar neutrino puzzle. Otherwise, the observed underabundance of He-3 in the presolar material and in H II regions must be considered as evidencing local inhomogeneities in the interstellar medium, in which He-3 is strongly depleted by some unknown process.

Printing Options

Print whole paper
Print Page(s) through

Return 600 dpi PDF to Acrobat/Browser. Different resolutions (200 or 600 dpi), formats (Postscript, PDF, etc), page sizes (US Letter, European A4, etc), and compression (gzip,compress,none) can be set through the Printing Preferences


More Article Retrieval Options

HELP for Article Retrieval
Bibtex entry for this abstract   Preferred format for this abstract (see Preferences)
  New!

Find Similar Abstracts:

Use: Authors
Title
Keywords (in text query field)
Abstract Text
Return: Query Results Return    items starting with number
Query Form
Database: Astronomy
Physics
arXiv e-prints