New theoretical yields of intermediate mass stars

Astronomy and Astrophysics – Astronomy

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

382

Stars: Abundances, Evolution, Agb, Ism: Abundances, Galaxies: Abundances

Scientific paper

We present theoretical yields of H, 4He, 12C, 13C, 14N, and 16O for stars with initial masses between 0.8 and 8 M_{\odot} and initial metallicities Z = 0.001, 0.004, 0.008, 0.02, and 0.04. We use the evolutionary tracks of the Geneva group up to the early asymptotic giant branch (AGB) in combination with a synthetic thermal-pulsing AGB evolution model to follow in detail the chemical evolution and mass loss up to the end of the AGB including the first, second, and third dredge-up phases. Most of the relations used are metallicity dependent to make a realistic comparison with stars of different initial abundances. The effect of Hot Bottom Burning (HBB) is included in an approximate way. The free parameters in our calculations are the mass loss scaling parameter etaAGB for stars on the AGB (using a Reimers law), the minimum core mass for dredge-up Mcmin, and the third dredge-up efficiency lambda. As derived from previous extensive modeling, etaAGB = 4, Mcmin = 0.58 M_{\odot}, and lambda = 0.75 including HBB are in best agreement with observations of AGB stars both in the Galactic disk and Magellanic Clouds. The influence of specific model assumptions and adopted parameter values on the resulting AGB yields is examined and compared with earlier theoretical work. We compare the abundances predicted during the final stages of the AGB with those observed in planetary nebulae in the Galactic disk and show that the model with the aforementioned parameters is in good agreement with the observations. The metallicity dependent yields of intermediate mass stars presented in this paper are well suited for use in galactic chemical evolution models. Tables also available at CDS via anonymous ftp 130.79.128.5 or on WWW at http://cdsweb.u-strasbg.fr/abstract.html.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

New theoretical yields of intermediate mass stars 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 New theoretical yields of intermediate mass stars, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and New theoretical yields of intermediate mass stars will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1472125

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.