2001/07/11 by Pavel A. Denissenkov, A. Weiss, Achim Weiss · 2 citations
Physics and Astronomy · #Astronomical and nuclear sciences #Nuclear physics research studies #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/323789
submitted to ApJ Letters
arxiv created 2001/07/11 · openalex publication_date 2001/10/01 · arxiv updated 2009/12/01 · openalex created_date 2019/06/27 · openalex updated_date 2026/07/31
We modify our combined ("deep mixing" plus "primordial") scenario explaining the star-to-star abundance variations in globular cluster red giants in such a way that it conforms with new experimental data: (1) the new and better constrained (NACRE) thermonuclear reaction rates and (2) a discovery of the O-Na anticorrelation in stars below the main-sequence turnoff in the cluster NGC 6752. For the latter, we propose that some main-sequence dwarfs in globular clusters accrete material lost by red giant primary components of close binaries during a common envelope event. As a consequence of the new reaction rates, we are drawn to the conclusion that the anomalies in [Al/Fe] in globular cluster red giants are in fact manifestations of 26 Al g abundance variations (instead of the stable isotope 27 Al) produced by deep mixing. However, Al overabundances observed in some of the subgiants in NGC 6752 are unlikely to be due to the unstable 26 Al g isotope but have to be the result of the other primordial component of our combined scenario, i.e., intermediate-mass asymptotic giant branch stars. These should also provide the source for enhanced 25 Mg, necessary for the 26 Al g production in deep mixing events.