EDP Sciences Journals List
Advanced Search
Subscriber Authentication Point
Home All issues Volume 376/2 Article
Free access article

Issue A&A
Volume 376, Number 2, September II 2001
Page(s) 422 - 433
Section Extragalactic astronomy
DOI http://dx.doi.org/10.1051/0004-6361:20011027



A&A 376, 422-433 (2001)
DOI: 10.1051/0004-6361:20011027

Confidence limits of evolutionary synthesis models

III. On time-integrated quantities
M. Cerviño1, 2, 3, M. A. Gómez-Flechoso4, F. J. Castander1, 5, 6, D. Schaerer1, M. Mollá7, J. Knödlseder2 and V. Luridiana8, 9

1  UMR CNRS 5572, Observatoire Midi-Pyrénées, 14 avenue Édouard Belin, 31400 Toulouse, France
2  Centre d'Études Spatiales des Rayonnements, CNRS/UPS, BP 4346, 31028 Toulouse Cedex 4, France
3  Max-Planck-Institut für extraterrestrische Physik, Giessenbachstrasse, 85748 Garching, Germany
4  Observatoire de Genève, 1290 Sauverny, Switzerland
5  Yale University, PO Box 208101, New Haven, CT 06520-8101, USA
6  Universidad de Chile, Casilla 36-D, Santiago, Chile
7  Departamento de Física Teórica C-XI, Universidad Autónoma de Madrid, 28049 Madrid, Spain
8  Instituto de Astronomía, UNAM, Apdo. Postal 70-264, 04510 México D.F., Mexico
9  European Southern Observatory, Karl-Schwarzschild-Str. 2, 85748 Garching bei München, Germany

(Received 8 June 2001 / Accepted 9 July 2001 )

Abstract
Evolutionary synthesis models are a fundamental tool to interpret the properties of observed stellar systems. In order to achieve a meaningful comparison between models and real data, it is necessary to calibrate the models themselves, i.e. to evaluate the dispersion due to the discreteness of star formation as well as the possible model errors. In this paper we show that linear interpolations in the $\log M - \log t_{k}$ plane, that are customary in the evaluation of isochrones in evolutionary synthesis codes, produce unphysical results. We also show that some of the methods used in the calculation of time-integrated quantities (kinetic energy, and total ejected masses of different elements) may produce unrealistic results. We propose alternative solutions to solve both problems. Moreover, we have quantified the expected dispersion of these quantities due to stochastic effects in stellar populations. As a particular result, we show that the dispersion in the 14N/12C ratio increases with time.


Key words: galaxies: starburst -- galaxies: evolution -- galaxies: statistics

Offprint request: M. Cerviño, mcs@laeff.esa.es

SIMBAD Objects in preparation



© ESO 2001


What is OpenURL?

The OpenURL standard is a protocol for transmission of metadata describing the resource that you wish to access. An OpenURL link contains article metadata and directs it to the OpenURL server of your choice. The OpenURL server can provide access to the resource and also offer complementary services (specific search engine, export of references...). The OpenURL link can be generated by different means.
  • If your librarian has set up your subscription with an OpenURL resolver, OpenURL links appear automatically on the abstract pages.
  • You can define your own OpenURL resolver with your EDPS Account. In this case your choice will be given priority over that of your library.
  • You can use an add-on for your browser (Firefox or I.E.) to display OpenURL links on a page (see http://www.openly.com/openurlref/). You should disable this module if you wish to use the OpenURL server that you or your library have defined.