Abundances of neutron-capture elements in G 24-25 A halo-population CH subgiant
Por:
Liu S., Nissen P.E., Schuster W.J., Zhao G., Chen Y.Q., Liang Y.C.
Publicada:
1 may 2012
Resumen:
Aims. The differences between the neutron-capture element abundances of halo stars are important to our understanding of the nucleosynthesis of elements heavier than the iron group. We present a detailed abundance analysis of carbon and twelve neutron-capture elements from Sr up to Pb for a peculiar halo star G24-25 with [Fe/H] = -1.4 in order to probe its origin. Methods. The equivalent widths of unblended lines are measured from high resolution NOT/FIES spectra and used to derive abundances based on Kurucz model atmospheres. In the case of CH, Pr, Eu, Gd, and Pb lines, the abundances are derived by fitting synthetic profiles to the observed spectra. Abundance analyses are performed both relative to the Sun and to a normal halo star G16-20 that has similar stellar parameters as G24-25. Results. We find that G24-25 is a halo subgiant star with an unseen component. It has large overabundances of carbon and heavy s-process elements and mild overabundances of Eu and light s-process elemen
Filiaciones:
Liu S.:
Key Laboratory of Optical Astronomy, National Astronomical Observatories, CAS, 20A Datun Road, Chaoyang District, 100012 Beijing, China
Graduate University, Chinese Academy of Sciences, 19A Yuquan Road, Shijingshan District, 100049 Beijing, China
Nissen P.E.:
Department of Physics and Astronomy, University of Aarhus, 8000 Aarhus C, Denmark
Schuster W.J.:
Univ Nacl Autonoma Mexico, Observ Astron Nacl, Ensenada 22800, Baja California, Mexico
Zhao G.:
Key Laboratory of Optical Astronomy, National Astronomical Observatories, CAS, 20A Datun Road, Chaoyang District, 100012 Beijing, China
Chen Y.Q.:
Key Laboratory of Optical Astronomy, National Astronomical Observatories, CAS, 20A Datun Road, Chaoyang District, 100012 Beijing, China
Liang Y.C.:
Key Laboratory of Optical Astronomy, National Astronomical Observatories, CAS, 20A Datun Road, Chaoyang District, 100012 Beijing, China
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