Meteoritic Silicon Carbide Grains with Unusual Si Isotopic Compositions: Evidence for an Origin in Low-Mass, Low-Metallicity Asymptotic Giant Branch Stars

Astronomy and Astrophysics – Astronomy

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

51

Stars: Circumstellar Matter, Ism: Dust, Extinction, Nuclear Reactions, Nucleosynthesis, Abundances, Stars: Evolution

Scientific paper

Nine silicon carbide grains of the rare type Z separated from the Murchison CM2 meteorite have been analyzed for the isotopic compositions of C, Si, N (seven grains), and Mg-Al (two grains) by ion microprobe mass spectrometry. These grains have 12C/13C ratios from 11 to 120, 14N/15N ratios between 1100 and 19000, initial 26Al/27Al ratios of less than 0.003, and, relative to solar system Si, deficits in 29Si of up to 150 ‰ and enrichments in 30Si of up to 510 ‰. These isotopic signatures rule out the previously postulated nova or Type II supernova origin of the Z grains. Based on the predictions from a new asymptotic giant branch (AGB) star model it appears likely that the Z grains formed in the outflows of low-mass (<2.3 Msolar), low-metallicity AGB stars that experienced strong cool bottom processing during the red giant phase.

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

Meteoritic Silicon Carbide Grains with Unusual Si Isotopic Compositions: Evidence for an Origin in Low-Mass, Low-Metallicity Asymptotic Giant Branch 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 Meteoritic Silicon Carbide Grains with Unusual Si Isotopic Compositions: Evidence for an Origin in Low-Mass, Low-Metallicity Asymptotic Giant Branch Stars, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Meteoritic Silicon Carbide Grains with Unusual Si Isotopic Compositions: Evidence for an Origin in Low-Mass, Low-Metallicity Asymptotic Giant Branch Stars will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1224869

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