[O/Fe] ESTIMATES FOR CARBON-ENHANCED METAL-POOR STARS FROM NEAR-INFRARED SPECTROSCOPY
- Department of Physics and Astronomy and JINA: Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, MI 48824 (United States)
- Indian Institute of Astrophysics, 2nd Block, Koramangala, Bangalore 560034 (India)
- Departamento de Astronomia-Instituto de Astronomia, Geofisica e Ciencias Atmosfericas, Universidade de Sao Paulo, Sao Paulo, SP 05508-900 (Brazil)
- Zentrum fuer Astronomie der Universitaet Heidelberg, Landessternwarte, Koenigstuhl 12, 69117 Heidelberg (Germany)
- Department of Physics and Astronomy, University of Victoria, Victoria, BC V8P5C2 (Canada)
- GRAAL-CNRS, Universite Montpellier II-UMR 5024, Place Eugene Bataillon, F-34095, Montpellier Cedex 05 (France)
We report on oxygen abundances determined from medium-resolution near-infrared spectroscopy for a sample of 57 carbon-enhanced metal-poor (CEMP) stars selected from the Hamburg/ESO Survey. The majority of our program stars exhibit oxygen-to-iron ratios in the range +0.5< [O/Fe]<+2.0. The [O/Fe] values for this sample are statistically compared to available high-resolution estimates for known CEMP stars as well as to high-resolution estimates for a set of carbon-normal metal-poor stars. Carbon, nitrogen, and oxygen abundance patterns for a sub-sample of these stars are compared to yield predictions for very metal-poor asymptotic giant branch (AGB) abundances in the recent literature. We find that the majority of our sample exhibit patterns that are consistent with previously studied CEMP stars having s-process-element enhancements and thus have very likely been polluted by carbon- and oxygen-enhanced material transferred from a metal-poor AGB companion.
- OSTI ID:
- 21583194
- Journal Information:
- Astronomical Journal (New York, N.Y. Online), Vol. 141, Issue 3; Other Information: DOI: 10.1088/0004-6256/141/3/102; ISSN 1538-3881
- Country of Publication:
- United States
- Language:
- English
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