Empirical Abundance Scaling Laws and Implications for the Gamma-Process in Core-Collapse Supernovae

Details Empirical Abundance Scaling Laws and Implications for the Gamma-Process in Core-Collapse Supernovae Empirical Abundance Scaling Laws and Implications for the Gamma-Process in Core-Collapse Supernovae

2009-01-23

arxiv.org/abs/0901.3592v1

Astrophys.J.685:1089-1102,2008

Astronomy and Astrophysics

Astrophysics

Solar and Stellar Astrophysics

35 pages, 15 figures

Scientific paper

10.1086/589938

Analyzing the solar system abundances, we have found two empirical abundance scaling laws concerning the p- and s-nuclei with the same atomic number. The first scaling is s/p ratios are almost constant over a wide range of the atomic number, where the p-nculei are lighter than the s-nuclei by two or four neutrons. The second scaling is p/p ratios are almost constant, where the second $p$-nuclei are lighter than the first p-nucleus by two neutrons. These scalings are a piece of evidence that most p-nuclei are dominantly synthesized by the gamma-process in supernova explosions. The scalings lead to a novel concept of "universality of gamma-process" that the s/p and p/p ratios of nuclei produced by individual gamma-processes are almost constant, respectively. We have calculated the ratios by gamma-process based on core-collapse supernova explosion models under various astrophysical conditions and found that the scalings hold for materials produced by individual gamma-processes independent of the astrophysical conditions assumed. The universality originates from three mechanisms: the shifts of the gamma-process layers to keep their peak temperature, the weak s-process in pre-supernovae, and the independence of the s/p ratios of the nuclear reactions. The results further suggest an extended universality that the s/p ratios in the gamma-process layers are not only constant but also centered on a specific value of 3. With this specific value and the first scaling, we estimate that the ratios of $s$-process abundance contributions from the AGB stars to the massive stars are almost 6.7 for the $s$-nuclei of A > 90. We find that large enhancements of s/p ratios for Ce, Er, and W are a piece of evidence that the weak s-process actually occurred before SNe.

Affiliated with

Also associated with

No associations

Rating

Empirical Abundance Scaling Laws and Implications for the Gamma-Process in Core-Collapse Supernovae 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 Empirical Abundance Scaling Laws and Implications for the Gamma-Process in Core-Collapse Supernovae, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Empirical Abundance Scaling Laws and Implications for the Gamma-Process in Core-Collapse Supernovae will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-65493