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Barium (Ba) stars are polluted by material enriched in the slow neutroncapture (s-process) elements synthesised in the interior of their formerasymptotic giant branch (AGB) companion star, which is now a white dwarf. Wecompare individual Ba star abundance patterns to AGB nucleosynthesis models toverify if the AGB model mass is compatible with independently derived AGB mass.We selected a sample of 28 Ba stars for which both self-consistentspectroscopic observation and analysis are available and stellar massdeterminations, via positioning the star on the HR diagram and comparing withevolutionary tracks. For this sample stars we considered both previously andrecently derived elemental abundances. Then, we performed a detailed comparisonof these s-process elemental abundances to different AGB nucleosynthesis modelsfrom the Monash and the FRUITY theoretical data sets. We simplified the binarymass transfer by calculating dilution factors to match the [Ce/Fe] value ofeach star when using different AGB models, and we then compared the dilutedmodel abundances to the complete Ba-star abundance pattern. Our comparisonconfirms that low mass, non-rotating AGB stellar models with 13C as the mainneutron source are the polluters of the vast majority of the considered Bastars. Out of the 28 stars, in 21 cases the models are in good agreement withboth the determined abundances and the independently derived AGB mass, althoughin 16 cases higher observed abundances of Nb, Ru, Mo and/or Nd, Sm thanpredicted. For 3 stars we obtain a match to the abundances only by consideringmodels with masses lower than those independently determined. Finally, 4 starsshow much higher first s-process peak abundance values than the modelpredictions, which may represent the signature of a physical and/ornucleosynthetic process that is not represented in the set of models consideredhere.

Barium stars as tracers of s-process nucleosynthesis in AGB stars I. 28 stars with independently derived AGB mass