Forum Springer Astron. Astrophys.
Forum Whats New Search Orders

Astron. Astrophys. 360, L5-L8 (2000)

Table of Contents
Available formats: HTML | PDF | (gzipped) PostScript

Letter to the Editor

Confidence levels of evolutionary synthesis models

M. Cerviño  *  1,2, V. Luridiana 3 and F.J. Castander 1

1 Observatoire Midi-Pyrénées, 14, avenue Edouard Belin, 31400 Toulouse, France
2 Centre d'Etude Spatiale des Rayonnements, CNRS/UPS, B.P. 4346, 31028 Toulouse Cedex 4, France
3 Instituto de Astronomía, UNAM, Apdo. Postal 70-264, 04510 México D.F., México

Received 8 June 2000 / Accepted 30 June 2000


The stochastic nature of the IMF in young stellar clusters implies that clusters of the same mass and age do not present the same unique values of their observed parameters. Instead they follow a distribution. We address the study of such distributions, parameterised in terms of their confidence limits, in evolutionary synthesis models. These confidence limits can be understood as the inherent uncertainties of the synthesis models. Here we concentrate on some parameters such as EW(H[FORMULA]) in emission. For instance, we show that for a cluster where 105 [FORMULA] have been transformed into stars, the dispersion of EW(H[FORMULA]) is about 18% within the 90% confidence levels at ages between 3.5 and 5 Myrs.

Key words: Galaxies:Evolution

* ESA posdoctoral fellow.

Send offprint requests to: Miguel Cerviño

Correspondence to: mcervino@obs-mip.fr

© European Southern Observatory (ESO) 2000

Online publication: July 27, 2000