EDP Sciences Journals List
Advanced Search
Subscriber Authentication Point
Home All issues Volume 389/1 Article
Free access article

Issue A&A
Volume 389, Number 1, July I 2002
Page(s) 106 - 114
Section Extragalactic astronomy
DOI http://dx.doi.org/10.1051/0004-6361:20020592



A&A 389, 106-114 (2002)
DOI: 10.1051/0004-6361:20020592

Chemical evolution of starburst galaxies: How does star formation proceed?

M. Mouhcine1, 2 and T. Contini1, 3

1  Observatoire Astronomique de Strasbourg, 11 rue de l'Université, 67000 Strasbourg, France
2  Division of Astronomy & Astrophysics, University of California, Los Angeles, CA 90095-1562, USA
3  Laboratoire d'Astrophysique de l'Observatoire Midi-Pyrénées - UMR 5572, 14 avenue E. Belin, 31400 Toulouse, France

(Received 6 August 2001 / Accepted 11 April 2002)

Abstract
We compute chemical evolution models to constrain the mode and the history of star formation in starburst galaxies as a whole, i.e. over a large range of mass and metallicity. To this end, we investigate the origin of the dispersion observed in the evolution of both nitrogen-to-oxygen abundance ratio and galaxy luminosity as a function of metallicity for a large sample of starburst galaxies. We find that the variation of the star formation efficiency, in the framework of continuous star formation models, produces a scatter equivalent to that observed in the N/O versus O/H diagram for low-mass HII galaxies only. However, continous star formation models are unable to reproduce i) the scatter observed for massive starburst and UV-selected galaxies in the N/O versus O/H relation, and ii) the scatter in the MB versus O/H scaling relation observed for the whole sample of starburst galaxies. The dispersion associated with the distribution of N/O as a function of metallicity, for both low-mass and massive galaxies, is well explained in the framework of bursting star formation models. It is interpreted as a consequence of the time-delay between the ejection of nitrogen and that of oxygen into the ISM. These models also reproduce the spread observed in the luminosity-metallicity relation. Metal-rich spiral galaxies differ from metal-poor ones by a higher star formation efficiency and starburst frequency. Low-mass galaxies experienced a few bursts of star formation whereas massive spiral galaxies experienced numerous and extended powerful starbursts. Finally, we confirm previous claims (Contini et al. 2002) that UV-selected galaxies are observed at a special stage in their evolution. Their low N/O abundance ratios with respect to other starburst galaxies is well explained if they have just undergone a powerful starburst that enriched their ISM in oxygen.


Key words: galaxies: starburst -- galaxies: abundances -- galaxies: evolution

Offprint request: T. Contini, contini@ast.obs-mip.fr




© ESO 2002


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.