Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.stsci.edu/ftp/stsci/library/abstracts/1134.abs Дата изменения: Thu Apr 17 20:57:50 1997 Дата индексирования: Sun Dec 23 00:17:45 2007 Кодировка: Поисковые слова: cygnus

\documentstyle{preprint}
\begin{document}
\title{DETECTION OF WOLF-RAYET STARS OF WN AND WC SUBTYPES\\
~\\
IN SUPER STAR CLUSTERS OF NGC~5253\thanks{Based on observations obtained at the European
Southern Observatory, Chile}}
\author{Daniel Schaerer\/\thanks{Also Observatoire de Gen\`eve, CH-1290
Sauverny, Switzerland}\\
\\
Space Telescope Science Institute, 3700 San Martin Drive, MD 21218\\
\and
Thierry Contini\/\thanks{Present address: School of Physics and Astronomy,
Tel Aviv University, 69978 Tel Aviv, Israel; contini@wise.tau.ac.il}\\
\\
UMR 5572, Observatoire Midi-Pyr\'en\'ees, 14 avenue E.~Belin, F-31400
Toulouse, France\\
\and
Daniel Kunth\\
\\
Institut d'Astrophysique de Paris, 98 bis Bd.~Arago, F-75014 Paris,
France\\
\and
Georges Meynet\\
\\
Observatoire de Gen\`eve, CH-1290 Sauverny, Switzerland}

\pub{ApJ (Letters)}
\recacc{21 November 1996}{13 March 1997}
\maketitle
\begin{abstract}
We present spectroscopic observations of the central star clusters in
NGC~5253 the aim of which is to search for WC stars. Our observations
show the presence of Wolf-Rayet (WR) stars not only of WN but also of WC
subtype in the two star forming regions corresponding to the maximum
optical and UV emission. The massive star population we derive is
consistent with young bursts of $\sim3$ and 4~Myr. The region of
maximum optical emission is found to provide the dominant contribution
of the ionizing flux as opposed to the less extinguished region of
maximum UV brightness. The presence of WR stars near the N-enriched
regions found by Walsh \& Roy (1987, 1989) and Kobulnicky \etal (1997)
suggests they are a possible source of N. It is presently unclear whether
or not our detection of WC stars is compatible with the normal observed He/O
and C/O abundance ratios.
\end{abstract}
\end{document}