Journal
ASTRONOMY & ASTROPHYSICS
Volume 548, Issue -, Pages -Publisher
EDP SCIENCES S A
DOI: 10.1051/0004-6361/201015615
Keywords
stars: abundances; stars: atmospheres; stars: chemically peculiar; stars: carbon
Categories
Funding
- CAPES [BEX 3448/06-1]
- FAPESP [2008/01265-0]
- CNPq [150370/2012-1]
- Physics Frontier Center/Joint Institute for Nuclear Astrophysics (JINA), US National Science Foundation [PHY 02-16783, PHY 08-22648]
- FAPESP
- CNPq
- CAPES
- STFC [ST/G002622/1] Funding Source: UKRI
- Science and Technology Facilities Council [ST/G002622/1] Funding Source: researchfish
Ask authors/readers for more resources
We present a detailed study of carbon-enhanced metal-poor (CEMP) stars, based on high-resolution spectroscopic observations of a sample of 18 stars. The stellar spectra for this sample were obtained at the 4.2 m William Herschel Telescope in 2001 and 2002, using the Utrecht Echelle Spectrograph, at a resolving power R similar to 52 000 and S/N similar to 40, covering the wavelength range lambda lambda 3700-5700 angstrom. The atmospheric parameters determined for this sample indicate temperatures ranging from 4750 K to 7100 K, log g from 1.5 to 4.3, and metallicities -3.0 <= [Fe/H]<=-1.7. Elemental abundances for C, Na, Mg, Sc, Ti, Cr, Cu, Zn, Sr, Y, Zr, Ba, La, Ce, Nd, Sm, Eu, Gd, Dy are determined. Abundances for an additional 109 stars were taken from the literature and combined with the data of our sample. The literature sample reveals a lack of reliable abundance estimates for species that might be associated with the r-process elements for about 67% of CEMP stars, preventing a complete understanding of this class of stars, since [Ba/Eu] ratios are used to classify them. Although eight stars in our observed sample are also found in the literature sample, Eu abundances or limits are determined for four of these stars for the first time. From the observed correlations between C, Ba, and Eu, we argue that the CEMP-r/s class has the same astronomical origin as CEMP-s stars, highlighting the need for a more complete understanding of Eu production.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available