Astronomy and Astrophysics – Astrophysics
Scientific paper
1998-04-07
Astronomy and Astrophysics
Astrophysics
30 pages LaTex, 16 postscript figues
Scientific paper
Multicolour images of the starbursting metal poor blue compact galaxy ESO338-IG04 have been obtained with WFPC2/HST. In the images we find numerous point-like sources concentrated towards the main body of the galaxy, which we identify as globular cluster candidates. We show that these objects are physically associated with the galaxy and that they are spatially extended. Given their high intrinsic luminosities, these objects cannot be individual stars. Using photometric evolution models we show that the objects constitute a rich population of massive star clusters with ages ranging from a few Myr to 10 Gyr, and masses ranging from 10^4 to more than 10^7 solar masses. We show that these objects are most likely globular clusters of varying age. There are peaks in the age distribution of the clusters: at <30 Myr, ~100 Myr, ~600 Myr, 2.5-5 Gyr and ~10 Gyr. The youngest objects are found in the crowded starburst region. The galaxy presently appears to be involved in a merger, which is the probable cause of the present globular cluster formation. The presence of a numerous intermediate age (2.5 to 5 Gyr) population of globular clusters, suggests that a previous merger might have occurred. As the starburst fades, this galaxy will become very rich in globular clusters. Transforming all objects to an age comparable to that of Milky Way globular clusters reveals a luminosity function similar to the Galactic. We suggest that this galaxy is the result of a merger between a dwarf elliptical and a gas rich dwarf. The possibility of dating the globular clusters offers an efficient way of studying the history of violent star formation in this and similar galaxies.
Bergvall Nils
Östlin Göran
Ronnback Jari
No associations
LandOfFree
Globular clusters in the blue compact galaxy ESO~338-IG04 (Tol~1924-416), as tracers of the star formation history. Results from HST/WFPC2 observations does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Globular clusters in the blue compact galaxy ESO~338-IG04 (Tol~1924-416), as tracers of the star formation history. Results from HST/WFPC2 observations, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Globular clusters in the blue compact galaxy ESO~338-IG04 (Tol~1924-416), as tracers of the star formation history. Results from HST/WFPC2 observations will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-433857