We investigate the star formation history and chemical evolution of low surface brightness (LSB) disk galaxies by modelling their observed spectro-photometric and chemical properties using a galactic chemical and photometric evolution model incorporating a detailed metallicity dependent set of stellar input data. For a large fraction of the LSB galaxies in our sample, observed properties are best explained by models incorporating an exponentially decreasing global star formation rate (SFR) ending at a present-day gas fraction M-gas/(M-gas + M-stars) = 0.5 for a galaxy age of 14 Gyr. For some galaxies small amplitude star formation bursts are required to explain the contribution of the young (5-50 Myr old) stellar population to the galaxy integrated luminosity. This suggests that star formation has proceeded in a stochastic manner.
The presence of an old stellar population in many late-type LSB galaxies suggests that LSB galaxies roughly follow the same evolutionary history as HSB galaxies, except nl a much lower rate. In particular, our results imply that LSB galaxies do not form late, nor have a delayed onset of star formation, but simply evolve slowly.
|Number of pages||17|
|Journal||Astronomy & astrophysics|
|Publication status||Published - May-2000|
- galaxies : evolution
- galaxies : fundamental parameters
- galaxies : formation
- galaxies : spiral
- STAR FORMATION RATES
- SPIRAL GALAXIES
- IRREGULAR GALAXIES
- MAGELLANIC CLOUDS
- GALACTIC DISKS
- VIRGO CLUSTER