Continuous star formation in BCD galaxies

Autor(en)

Simone Recchi, Gerhard Hensler

Abstrakt

Blue Compact Dwarf galaxies are generally believed to be unevolved objects, due to their blue colors, compact appearance and large gas fractions. Owing to the short gas consumption time-scales, they have been thought to be very young and characterized by bursting star formation. By means of 2-D hydrodynamical simulations, coupled with detailed chemical yields originating from SNeII, SNeIa and intermediate-mass stars, we study the dynamical and chemical evolution of galaxies with structural parameters similar to the Blue Compact Galaxies IZw18 and NGC1569. Bursts of star formation with negligible durations are not able to account for the chemical and morphological properties of these galaxies. The best way to reproduce the chemical composition of these objects is by assuming a long-lasting episode of star formation (270 Myr for IZw18 and 1.4 Gyr for NGC1569) and a more recent episode, separated from the previous one by a short quiescent period. In most of the explored cases, the derived chemical composition of the galaxy is dominated by the products of the old stars, since the enriched gas produced by young stars is in a too hot phase to be detectable with the optical spectroscopy. © 2005 American Institute of Physics.

Organisation(en)

Institut für Astrophysik

Seiten

105-111

Anzahl der Seiten

7

DOI

https://doi.org/10.1063/1.2034973

Publikationsdatum

2005

ÖFOS 2012

103003 Astronomie

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/38f18544-f27e-4f5f-bc3d-a122a2553cb6