Puzeras, E. and Tautvaišienė, G. and Cohen, J. G. and Gray, D. F. and Adelman, S. J. and Ilyin, I. and Chorniy, Y. (2010) High-resolution spectroscopic study of red clump stars in the Galaxy: iron-group elements. Monthly Notices of the Royal Astronomical Society, 408 (2). pp. 1225-1232. ISSN 0035-8711 http://resolver.caltech.edu/CaltechAUTHORS:20101101-105709114
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The main atmospheric parameters and abundances of the iron-group elements (vanadium, chromium, iron, cobalt and nickel) are determined for 62 red giant ‘clump’ stars revealed in the Galactic field by the Hipparcos orbiting observatory. The stars form a homogeneous sample with the mean value of temperature T_(eff)= 4750 ± 160 K, of surface gravity log g= 2.41 ± 0.26 and the mean value of metallicity [Fe/H]=−0.04 ± 0.15 dex. A Gaussian fit to the [Fe/H] distribution produces the mean 〈[Fe/H]〉=−0.01 and dispersion σ_([Fe/H])= 0.08. The near-solar metallicity and small dispersion of σ_([Fe/H]) of clump stars of the Galaxy obtained in this paper confirm the theoretical model of the Hipparcos clump by Girardi & Salaris. This suggests that nearby clump stars are (in the mean) relatively young objects, reflecting mainly the near-solar metallicities developed in the local disc during the last few Gyr of its history. We find iron-group element to iron-abundance ratios in clump giants to be close to solar.
|Additional Information:||© 2010 The Authors. Journal compilation © 2010 RAS. Accepted 2010 June 14. Received 2010 June 14; in original form 2010 May 20. Article first published online: 17 Aug. 2010. This project has been supported by the European Commission through the Baltic Grid project as well as through ‘Access to Research Infrastructures Action’ of the ‘Improving Human Potential Programme’, awarded to the Instituto de Astrofísica de Canarias to fund European Astronomers’ access to the European Nordern Observatory, in the Canary Islands. EP and GT acknowledge support from the Lithuanian National Science and Studies Foundation through GridTechno project. JGC acknowledges the inspiration of the late Bohdan Paczynski for stimulating her interest in this area and is grateful to NSF grant AST-0507219 and AST-0908139 for partial support. DFG is grateful for financial support from the Natural Sciences and Engineering Research Council of Canada. SJA thanks Dr James E. Hesser, Director of the Dominion Astronomical Observatory, for the observing time used for this project and Dr Austin Gulliver for help in reducing the DAO Spectrograms. Financial support was provided to SJA by The Citadel Foundation.|
|Subject Keywords:||stars: abundances; stars: atmospheres; stars: horizontal branch|
|Official Citation:||Puzeras, E., Tautvaišienė, G., Cohen, J. G., Gray, D. F., Adelman, S. J., Ilyin, I. and Chorniy, Y. (2010), High-resolution spectroscopic study of red clump stars in the Galaxy: iron-group elements. Monthly Notices of the Royal Astronomical Society, 408: 1225–1232. doi: 10.1111/j.1365-2966.2010.17195.x|
|Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Jason Perez|
|Deposited On:||01 Nov 2010 20:32|
|Last Modified:||26 Dec 2012 12:35|
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