Astronomy and Astrophysics – Astrophysics
Scientific paper
2000-09-07
Astrophys.Space Sci. 277 (2001) 183-187
Astronomy and Astrophysics
Astrophysics
to appear in "Evolution of Galaxies. I. Observational clues", Eds. J.M. Vilchez, G. Stasinska, Astrophysics and Space Science,
Scientific paper
10.1023/A:1012753711017
The similarity between observed velocity structures of Al III and singly ionised species in damped Lyman-alpha systems (DLAs) suggests the presence of ionised gas in the regions where most metal absorption lines are formed. To explore the possible implications of ionisation effects we construct a simplified two-region model for DLAs consisting of an ionisation bounded region with an internal radiation field and a neutral region with a lower metal content. Within this framework we find that ionisation effects are important. If taken into account, the element abundance ratios in DLAs are quite consistent with those observed in Milky Way stars and in metal-poor H II regions in blue compact dwarf galaxies. In particular we cannot exclude the same primary N origin in both DLAs and metal-poor galaxies. From our models no dust depletion of heavy elements needs to be invoked; little depletion is however not excluded.
Charbonnel Corinne
Izotov Yuri
Schaerer Daniel
No associations
LandOfFree
On ionisation effects and abundance ratios in damped Lyman-alpha systems 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 On ionisation effects and abundance ratios in damped Lyman-alpha systems, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and On ionisation effects and abundance ratios in damped Lyman-alpha systems will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-721927