LINK<\/strong><\/a><\/p>\n\n\n\n“Certain types of silicon carbide (SiC) grains, e.g. SiC-X grains, and low density (LD) graphites are C-rich presolar grains that are thought to have condensed in the ejecta of core-collapse supernovae (CCSNe). In this work we compare C, N, Al, Si, and Ti isotopic abundances measured in presolar grains with the predictions of 21 CCSN models. The impact of a range of SN explosion energies is considered, with the high energy models favouring the formation of a C\/Si zone enriched in 12C, 28Si, and 44Ti. Eighteen of the 21 models have H ingested into the He-shell and different abundances of H remaining from such H-ingestion. CCSN models with intermediate to low energy (that do not develop a C\/Si zone) cannot reproduce the 28Si and 44Ti isotopic abundances in grains without assuming mixing with O-rich CCSN ejecta. The most 28Si-rich grains are reproduced by energetic models when material from the C\/Si zone is mixed with surrounding C-rich material, and the observed trends of the 44Ti\/48Ti and 49Ti\/48Ti ratios are consistent with the C-rich C\/Si zone. For the models with H-ingestion, high and intermediate explosion energies allow the production of enough 26Al to reproduce the 26Al\/27Al measurements of most SiC-X and LD graphites. In both cases, the highest 26Al\/27Al ratio is obtained with H still present at XH \u2248 0.0024 in He-shell material when the SN shock is passing. The existence of H in the former convective He-shell points to late H-ingestion events in the last days before massive stars explode as a supernova.”<\/p>\n","protected":false},"excerpt":{"rendered":"
Jordan Schofield, Marco Pignatari, Richard J Stancliffe, Peter Hoppe Monthly Notices of the Royal Astronomical Society, stac2498Published: 08 September 2022 LINK “Certain types of silicon carbide (SiC) grains, e.g. SiC-X grains, and low density (LD)…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[76],"tags":[1853,539,1712,2323],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/31231"}],"collection":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=31231"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/31231\/revisions"}],"predecessor-version":[{"id":31232,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/31231\/revisions\/31232"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=31231"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=31231"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=31231"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}