{"id":36354,"date":"2024-06-23T12:07:35","date_gmt":"2024-06-23T10:07:35","guid":{"rendered":"https:\/\/karmaka.de\/?p=36354"},"modified":"2024-06-23T12:07:36","modified_gmt":"2024-06-23T10:07:36","slug":"isotope-studies-of-presolar-silicon-carbide-grains-from-supernovae-new-constraints-for-hydrogen-ingestion-supernova-models","status":"publish","type":"post","link":"https:\/\/karmaka.de\/?p=36354","title":{"rendered":"Isotope studies of presolar silicon carbide grains from supernovae: new constraints for hydrogen-ingestion supernova models<span class=\"badge-status\" style=\"background:#787878\">OPEN ACCESS<\/span>&nbsp;"},"content":{"rendered":"\n<p>Peter Hoppe, Jan Leitner, Marco Pignatari, and Sachiko Amari<\/p>\n\n\n\n<p>Monthly Notices of the Royal Astronomical Society, stae1523<br>Published: 19 June 2024<\/p>\n\n\n\n<p><a href=\"https:\/\/academic.oup.com\/mnras\/advance-article\/doi\/10.1093\/mnras\/stae1523\/7696339\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>LINK (OPEN ACCESS)<\/strong><\/a><\/p>\n\n\n\n<p class=\"justify-text\">&#8220;We report isotope data for C, N, Al, Si, and S of 33 presolar SiC and Si3N4 grains (0.3\u20131.6 \u03bcm) of Type X, C, D, and N from the Murchison CM2 meteorite of likely core-collapse supernova (CCSN) origin which we discuss together with data of six SiC X grains from an earlier study. The isotope data are discussed in the context of hydrogen ingestion supernova (SN) models. We have modified previously used ad-hoc mixing schemes in that we considered (i) heterogeneous H ingestion into the He shell of the pre-SN star, (ii) a variable C-N fractionation for the condensation of SiC grains in the SN ejecta, and (iii) smaller mass units for better fine-tuning. With our modified ad-hoc mixing approach over small scales (0.2\u20130.4 M\u00a4), with major contributions from the O-rich O\/nova zone, we find remarkably good fits (within a few per cent) for 12C\/13C, 26Al\/27Al, and 29Si\/28Si ratios. The 14 N\/15 N ratio of SiC grains can be well matched if variable C-N fractionation is considered. However, the Si3N4 isotope data point to overproduction of 15 N in hydrogen ingestion CCSN models and lower C-N fractionation during SiC condensation than applied here. Our ad-hoc mixing approach based on current CCSN models suggests that the O-rich O\/nova zone, which uniquely combines explosive H- and He-burning signatures, is favorable for SiC and Si3N4 formation. The effective range of C\/O abundance variations in the He shell triggered by H ingestion events in the massive star progenitor is currently not well constrained and needs further investigation.&#8221;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Peter Hoppe, Jan Leitner, Marco Pignatari, and Sachiko Amari Monthly Notices of the Royal Astronomical Society, stae1523Published: 19 June 2024 LINK (OPEN ACCESS) &#8220;We report isotope data for C, N, Al, Si, and S of&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[9,18,76],"tags":[526,4290,3065,4776,3273,105,107,1853,539,1712],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/36354"}],"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=36354"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/36354\/revisions"}],"predecessor-version":[{"id":36355,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/36354\/revisions\/36355"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=36354"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=36354"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=36354"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}