Astrophysics with Radioactive Isotopes

Short-lived radioactive isotopes from massive binary stars and the early Solar System

Not scheduled

20m

Oral Presentation

Speaker

Hannah Brinkman

Description

Massive stars eject the products of their nuclear burning into the stellar medium via stellar winds and supernova explosion. Chemical yields from single massive stars are widely available in the literature. However, massive stars are often found in binary systems, and the effects of binary interactions on the yields have not been taken into account in most previous studies. We present our work aimed to fill this gap. We have used the MESA stellar evolution code to compute massive stars with initial masses from 10-80Msun both rotating and non-rotating at solar metallicity (Z=0.014) and their massive non-rotating binary counterparts. From these simulations we have calculated the wind yields for the single stars and for those binary systems where mass transfer plays a major role. We studied the short-lived radioactive nuclei aluminium-26, which is of relevance for to galactic gamma-rays and to the formation of the Solar System as a case study. We found that for binary systems with massive stars up to ~35-40Msun the yield can increase up to two orders of magnitude, while above ~45Msun the yield becomes similar to the single star yield, or even decreases. We also considered the radioactive isotopes chlorine-36 and calcium-41 to identify which stellar sources are potentially responsible for the injection of these isotopes into the early Solar System. We find that for the single stars, only the most massive, rotating stars in our sample can match the early Solar System abundances. Especially chlorine-36 is hard to match. However, when we include binary interactions, the upper limit for the mass lowers, and we find more potential sources for these three isotopes.