Structure, convective mixing and nuclear burning. Which has a fully implicit and simultaneous method for solving for the stellar Solar metallicity calculated with the Eggleton stellar evolution code (STARS), Stancliffe (IoA and 4 other authors Download PDF Abstract: We present results of the evolution of AGB stars of 3M_sol and 5M_sol with All rights reserved.Download a PDF of the paper titled Deep Dredge-up in Intermediate-Mass TP-AGB Stars, by R.J. This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2020 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. The net effect is an underestimate of the initial N-abundance ranges from RGB photometry if the first dredge-up is not accounted for in the modelling, and also the potential determination of spurious trends of N-abundance spreads with age. This reduction is a strong function of age and has also a dependence on metallicity. We find that for a given initial range of N abundances, the first dredge up reduces the predicted RGB widths in N-sensitive filters compared to the case when its effect on the stellar spectral energy distributions is not accounted for. We have filled this gap by studying theoretically the impact of the dredge-up on the predicted widths of RGBs in clusters hosting MPs.
An important issue not yet properly addressed is that the translation of the observed widths of the cluster RGBs to abundance spreads must account for the effect of the first dredge-up on the surface chemical patterns, hence on the spectral energy distributions of stars belonging to the various MPs.
Photometry of red giant branch (RGB) stars has been and still is instrumental in enabling the detection and characterization of cluster MPs, through the appropriate choices of filters, colours and colour combinations, that are mainly sensitive to N and -to a lesser degree- C stellar surface abundances. The existence of star-to-star light-element abundance variations (multiple populations, MPs) in massive Galactic and extragalactic star clusters older than about 2 Gyr is by now well established.
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