Sökning: onr:"swepub:oai:DiVA.org:uu-25513" >
The frequency of ca...
The frequency of carbon-enhanced metal-poor stars in the galaxy from the HERES sample
-
Lucatello, S. (författare)
-
Beers, T. (författare)
-
- Christlieb, Norbert (författare)
- Uppsala universitet,Institutionen för astronomi och rymdfysik
-
visa fler...
-
- Barklem, Paul (författare)
- Uppsala universitet,Institutionen för astronomi och rymdfysik
-
Rossi, S. (författare)
-
Marsteller, B. (författare)
-
Sivarani, T. (författare)
-
Sun Lee, Y. (författare)
-
visa färre...
-
(creator_code:org_t)
- 2006-10-31
- 2006
- Engelska.
-
Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 652:1, s. L37-L40
- Relaterad länk:
-
https://urn.kb.se/re...
-
visa fler...
-
https://doi.org/10.1...
-
visa färre...
Abstract
Ämnesord
Stäng
- We estimate the frequency of carbon-enhanced metal-poor (CEMP) stars among very metal-poor stars, based on an analysis of 349 stars with available high-resolution spectra observed as part of the Hamburg/ESO R-process Enhanced Star (HERES) survey. We obtain that a lower limit of 21% +/- 2% of stars with [Fe/H] <= -2.0 exhibit [C/Fe] >= +1.0. These fractions are higher than those that have been reported by recent examinations of this question, based on substantially smaller samples of stars. We discuss the source of this difference and suggest that in order to take into account effects that result in a decrease of surface carbon abundance with advancing evolution, a definition of CEMP stars based on a [C/Fe] cutoff that varies as a function of luminosity is more appropriate. We discuss the likely occurrence of dilution and mixing for many CEMP stars, which, if properly accounted for, would increase this fraction still further.
Ämnesord
- NATURVETENSKAP -- Fysik (hsv//swe)
- NATURAL SCIENCES -- Physical Sciences (hsv//eng)
Nyckelord
- Galaxy : halo; stars : abundances; stars : carbon; stars : Population II
- Physics
- Fysik
Publikations- och innehållstyp
- ref (ämneskategori)
- art (ämneskategori)
Hitta via bibliotek
Till lärosätets databas