Astronomy and Astrophysics – Astrophysics
Scientific paper
2000-01-17
Astronomy and Astrophysics
Astrophysics
10 pages, 4 Postscript figures, to be published in Astronomy and Astrophysics main journal
Scientific paper
Deep long-slit spectroscopic observations of the blue compact galaxy IZw 18 obtained with the CFH 3.6 m Telescope are presented. The very low value of oxygen abundance previously reported is confirmed and a very homogeneous abundance distribution is found (no variation larger than 0.05 dex) over the whole ionized region. We concur with Tenorio-Tagle (1996) and Devost et al. (1997) that the observed abundance level cannot result from the material ejected by the stars formed in the current burst, and propose that the observed metals were formed in a previous star formation episode. Metals ejected in the current burst of star formation remain most probably hidden in a hot phase and are undetectable using optical spectroscopy. We discuss different scenarios of star formation in IZw 18. Combining various observational facts, for instance the faint star formation rate observed in low surface brightness galaxies van Zee et al. (1997), it is proposed that a low and continuous rate of star formation occurring during quiescent phases between bursts could be a significant source of metal enrichment of the interstellar medium.
Kunth Daniel
Legrand François
Mas-Hesse Jose Miguel
ROY Jean-Rene
Walsh Jonathan R.
No associations
LandOfFree
A continuous low star formation rate in IZw 18 ? 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 A continuous low star formation rate in IZw 18 ?, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A continuous low star formation rate in IZw 18 ? will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-429466