Bibcode
Bandyopadhyay, A.; Sivarani, Thirupathi; Susmitha, Antony; Beers, Timothy C.; Giridhar, Sunetra; Surya, Arun; Masseron, T.
Referencia bibliográfica
The Astrophysical Journal, Volume 859, Issue 2, article id. 114, 17 pp. (2018).
Fecha de publicación:
6
2018
Revista
Número de citas
11
Número de citas referidas
10
Descripción
SDSS J082625.70+612515.10 (V = 11.4 [Fe/H] = ‑3.1) and SDSS
J134144.60+474128.90 (V = 12.4 [Fe/H] = ‑3.2) were observed with
the SDSS 2.5m telescope as part of the SDSS MARVELS spectroscopic
pre-survey and identified as extremely metal-poor (EMP; [Fe/H] <‑3.0) stars during the high-resolution follow-up using the Hanle
Echelle Spectrograph (HESP) on the 2.0-m Himalayan Chandra Telescope. In
this paper, the first science results using HESP, we present a detailed
analysis of their chemical abundances. Both stars exhibit
under-abundances in their neutron capture elements, while one of them
(SDSS J134144.60+474128.90) is clearly enhanced in carbon. Lithium was
also detected in this star at a level of about A(Li) = 1.95. The spectra
were obtained over a span of 6–24 months, and indicate that both
stars could be members of binary systems. We compare the elemental
abundances derived for these two stars along with other carbon-enhanced
metal-poor (CEMP) and EMP stars, in order to understand the nature of
their parent supernovae. We find that CEMP-no stars and EMP-dwarfs show
a very similar trend in their lithium abundances at various
metallicities. We also find indications of CEMP-no stars having larger
abundances of Cr and Co at given metallicities compared to EMP stars.
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