Astronomy and Astrophysics – Astrophysics
Scientific paper
Aug 2006
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2006iaujd..11e..11y&link_type=abstract
Pre-Solar Grains as Astrophysical Tools, 26th meeting of the IAU, Joint Discussion 11, 21 August 2006, Prague, Czech Republic, J
Astronomy and Astrophysics
Astrophysics
Scientific paper
Introduction: Most of SiC X and low density graphite grains show excesses of ^28Si and some of them have an evidence for the original presence of ^44Ti, so that they are believed to originate from supernovae. The isotopic and elemental signatures are considered to reflect large-scale heterogeneous mixing in supernova ejecta. We investigate supernova mixtures indicating isotopic ratios of individual single SiC X and low density graphite grains as many as possible. Supernova mixing model: We use the abundance distribution of the supernova ejecta of He star models of 3.3, 4, 6, and 8 solar masses in Yoshida, Umeda, & Nomoto (2005; ApJ 631, 1039), which correspond to zero-age main sequence stars of 13, 15, 20, and 25 solar masses. We divide the supernova ejecta into seven layers, i.e., the Ni, Si/S, O/Si, O/Ne, C/O or O/C, He/C, and He/N layers. Then, for individual single SiC X and low density graphite grains, we seek the mixtures indicating the smallest difference in several isotopic ratios from the corresponding grains. Results: In the case of SiC X grains, the mixtures reproducing five isotopic ratios in ^ 12C/^13C, ^14N/^15N, ^16O/^17O, ^16O/^18O, ^26Al/^27Al, ^29Si/^28Si, ^30Si/^ 28Si, and ^44Ti/^48Ti are obtained. For nineteen low density graphite grains, the mixtures reproducing six isotopic ratios in ^12C/^13C, ^14N/^15N, ^16O/^ 17O, ^16O/^18O, ^26Al/^27Al, ^29Si/^28Si, and ^30Si/^28Si. The isotopic ratio different from the corresponding grains is one of ^12C/^13C, ^14N/^15N, and ^ 26Al/^27Al in most cases. The mixing ratios of the mixtures strongly depend on reproduced isotopic ratios. The main component of the mixtures is one of the Ni, He/C, and He/N layers for most mixtures. Most of the obtained mixtures indicate the C/O ratio larger than unity.
No associations
LandOfFree
Supernova Mixtures Indicating Isotopic Ratios of Presolar Grains 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 Supernova Mixtures Indicating Isotopic Ratios of Presolar Grains, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Supernova Mixtures Indicating Isotopic Ratios of Presolar Grains will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1785102