Reference : The photospheric abundances of active binaries. II. Atmospheric parameters and abundance...
Scientific journals : Article
Physical, chemical, mathematical & earth Sciences : Space science, astronomy & astrophysics
http://hdl.handle.net/2268/31994
The photospheric abundances of active binaries. II. Atmospheric parameters and abundance patterns for 6 single-lined RS CVn systems
English
Morel, Thierry [Osservatorio Astronomico di Palermo G. S. Vaiana, Istituto Nazionale di Astrofisica > > > >]
Micela, G. [Istituto Nazionale di Astrofisica, Osservatorio Astronomico di Palermo G. S. Vaiana, Piazza del Parlamento 1, 90134 Palermo, Italy]
Favata, F. [Astrophysics Division, Research and Science Support Department of ESA, ESTEC, Postbus 299, 2200 AG Noordwijk, The Netherlands]
Katz, D. [Observatoire de Paris, GEPI, place Jules Janssen, 92195 Meudon, France]
Pillitteri, I. [Dipartimento di Scienze Fisiche ed Astronomiche, Università di Palermo, Piazza del Parlamento 1, 90134 Palermo, Ital]
1-Dec-2003
Astronomy and Astrophysics
EDP Sciences
412
495-512
Yes (verified by ORBi)
International
0004-6361
1432-0746
Les Ulis
France
[en] stars: fundamental parameters ; stars: abundances
[en] Photospheric parameters and abundances are presented for a sample of single-lined chromospherically active binaries from a differential LTE analysis of high-resolution spectra. Abundances have been derived for 13 chemical species, including several key elements such as Li, Mg, and Ca. Two methods have been used. The effective temperatures, surface gravities and microturbulent velocities were first derived from a fully self-consistent analysis of the spectra, whereby the temperature is determined from the excitation equilibrium of the Fe I lines. The second approach relies on temperatures derived from the (B-V) colour index. These two methods give broadly consistent results for the stars in our sample, suggesting that the neutral iron lines are formed under conditions close to LTE. We discuss the reliability in the context of chromospherically active stars of various colour indices used as temperature indicators, and conclude that the (V-R) and (V-I) colours are likely to be significantly affected by activity processes. Irrespective of the method used, our results indicate that the X-ray active binaries studied are not as metal poor as previously claimed, but are at most mildly iron-depleted relative to the Sun (-0.41protect <~ [Fe/H]protect la +0.11). A significant overabundance of several chemical species is observed (e.g., the alpha -synthezised elements). These abundance patterns are discussed in relation to stellar activity. Based on observations collected at ESO (La Silla, Chile). Table A.1 is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/412/495
http://hdl.handle.net/2268/31994
10.1051/0004-6361:20031469
http://adsabs.harvard.edu/abs/2003A%26A...412..495M
http://de.arxiv.org/abs/astro-ph/0309535

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