THE RAVE SURVEY: RICH IN VERY METAL-POOR STARS
- Department of Physics and Astronomy, Johns Hopkins University, 366 Bloomberg Center, 3400 North Charles Street, Baltimore, MD 21218 (United States)
- Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom)
- Astronomisches Rechen-Institut, Zentrum fuer Astronomie der Universitaet Heidelberg, Moenchhofstr. 12-14, D-69120 Heidelberg (Germany)
- Observatoire de Strasbourg, 11 Rue de L'Universite, 67000 Strasbourg (France)
- Rudolf Pierls Center for Theoretical Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP (United Kingdom)
- Anglo-Australian Observatory, P.O. Box 296, Epping, NSW 1710 (Australia)
- Western Kentucky University, Bowling Green, KY (United States)
- RSAA Australian National University, Mount Stromlo Observatory, Cotter Road, Weston Creek, Canberra, ACT 72611 (Australia)
- Jeremiah Horrocks Institute for Astrophysics and Super-computing, University of Central Lancashire, Preston (United Kingdom)
- Kapteyn Astronomical Institute, University of Groningen, Postbus 800, 9700 AV Groningen (Netherlands)
- INAF Osservatorio Astronomico di Padova, Via dell'Osservatorio 8, Asiago I-36012 (Italy)
- University of Victoria, P.O. Box 3055, Station CSC, Victoria, BC V8W 3P6 (Canada)
- Macquarie University, Sydney, NSW 2109 (Australia)
- Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, RH5 6NT (United Kingdom)
- Astrophysikalisches Institut Potsdam, An der Sternwarte 16, D-14482 Potsdam (Germany)
Very metal-poor stars are of obvious importance for many problems in chemical evolution, star formation, and galaxy evolution. Finding complete samples of such stars which are also bright enough to allow high-precision individual analyses is of considerable interest. We demonstrate here that stars with iron abundances [Fe/H] <-2 dex, and down to below -4 dex, can be efficiently identified within the Radial Velocity Experiment (RAVE) survey of bright stars, without requiring additional confirmatory observations. We determine a calibration of the equivalent width of the calcium triplet lines measured from the RAVE spectra onto true [Fe/H], using high spectral resolution data for a subset of the stars. These RAVE iron abundances are accurate enough to obviate the need for confirmatory higher-resolution spectroscopy. Our initial study has identified 631 stars with [Fe/H] {<=}-2, from a RAVE database containing approximately 200,000 stars. This RAVE-based sample is complete for stars with [Fe/H] {approx_lt}-2.5, allowing statistical sample analysis. We identify three stars with [Fe/H] {approx_lt}-4. Of these, one was already known to be 'ultra metal-poor', one is a known carbon-enhanced metal-poor star, but we obtain [Fe/H] = -4.0, rather than the published [Fe/H] = -3.3, and derive [C/Fe] = +0.9, and [N/Fe] = +3.2, and the third is at the limit of our signal-to-noise ratio. RAVE observations are ongoing and should prove to be a rich source of bright, easily studied, very metal-poor stars.
- OSTI ID:
- 21452656
- Journal Information:
- Astrophysical Journal Letters, Vol. 724, Issue 1; Other Information: DOI: 10.1088/2041-8205/724/1/L104; ISSN 2041-8205
- Country of Publication:
- United States
- Language:
- English
Similar Records
Spectroscopic Validation of Low-metallicity Stars from RAVE
The metal-poor stellar halo in RAVE-TGAS and its implications for the velocity distribution of dark matter