Mathematics – Logic
Scientific paper
Mar 1977
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1977apj...212..347h&link_type=abstract
Astrophysical Journal, Part 1, vol. 212, Mar. 1, 1977, p. 347-359.
Mathematics
Logic
17
Astronomical Models, Chemical Evolution, Cosmology, Galactic Evolution, Nuclear Fusion, Stellar Evolution, Abundance, Atmospheric Composition, Chronology, Half Life, Neutron Cross Sections, Stellar Temperature
Scientific paper
Long-lived nucleochronologies are calculated for several recently proposed models of the chemical evolution of the Galaxy. Special attention is paid to the Re-187/Os-187 chronometer, for which important data have recently become available. It is found that although the rate of star formation does vary with time in the different models, the quantity that is related to the effective net rate of nucleosynthesis is constant for most of the physically plausible recent-evolution models examined. This constant net rate implies that for these models, the age of the Galaxy at the time the solar system formed is twice the mean age of the stable elements. This mean age can be estimated by the parameter 'delta max', in which case the age of the Galaxy is twice this parameter plus the age of the solar system. The present uncertainties in 'delta max' yield an age for the Galaxy of 7 to 20 billion years. However, this range could be significantly reduced by an accurate measurement of the half-life of Re-187 and more knowledge on the effect of stellar temperatures on the Os-186/Os-187 neutron-capture cross-section ratio. In fact, experiments which could be carried out in the next few years can reduce these uncertainties tremendously and enable an age determination to be made which might severely restrict cosmological models.
Hainebach Kem Lawrence
Schramm David N.
No associations
LandOfFree
Comments on galactic evolution and nucleocosmochronology does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Comments on galactic evolution and nucleocosmochronology, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Comments on galactic evolution and nucleocosmochronology will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1845461