Abundances of neutron-capture elements in atmospheres of cool giants

O. Bienaymé (1) , T. I. Gorbaneva (2) , V. V. Kovtyukh (2) , T. V. Mishenina (3) , C. Soubiran (1, 4, 5, 6) , L. F. Orlova (2)

1 OAS - Observatoire astronomique de Strasbourg
2 Odessa Astronomical Observatory
3 Astronomical observatory of Odessa National University [Odessa]
4 LAB - Laboratoire d'Astrophysique de Bordeaux [Pessac]
5 L3AB - Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux
6 OASU - Observatoire aquitain des sciences de l'univers

We have determined the atmospheric abundances of Y, Ba, La, Ce, Pr, Nd, and Eu for a sample of 171 giants selected as clump giants with metallicities [Fe/H] between ?0.7 and 0.3 dex, based on photometric criteria. In our analysis, we assumed local thermodynamic equilibrium and fit the parameters of model atmospheres to high-resolution (R = 42 000) echelle spectra with high signal-to-noise ratios. The Ba and Eu abundances were derived using synthetic spectra, including hyperfine structure. We find no significant difference in the abundances of s-or r-process neutron-capture elements between clump giants and ascending-branch giants selected by us earlier. We also analyze the relation between the abundances of neutron-capture elements and [Fe/H].

Domains: Cosmology and Extra-Galactic Astrophysics [astro-ph.CO]; Astrophysics [astro-ph]

O. Bienaymé, T. I. Gorbaneva, V. V. Kovtyukh, T. V. Mishenina, C. Soubiran, et al.. Abundances of neutron-capture elements in atmospheres of cool giants. Astronomy Reports, 2007, 51 (5), pp.382-393. ⟨10.1134/S1063772907050046⟩. ⟨hal-00155477⟩