Astronomy and Astrophysics – Astrophysics
Scientific paper
2004-04-15
Astronomy and Astrophysics
Astrophysics
8 pages, invited contribution for the Cancun Workshop on Formation and Evolution of Young Massive Clusters, eds. H.J. Lamers,
Scientific paper
In this talk I discuss the role of proto-globular clusters as the dominant sources of radiation that reionised hydrogen in the intergalactic medium (IGM) at redshift z~6. Observations at lower redshifts indicate that only a small fraction, f_esc, of hydrogen ionising radiation emitted from massive stars can escape unabsorbed by the galaxy into the IGM. High redshift galaxies are expected to be more compact and gas rich than present day galaxies, consequently f_esc from their disks or spheroids might have been very small. But if the sites of star formation in the galaxies are off-centre and if the star formation efficiency of the proto-clusters is high, then the mean f_esc calculated for these objects only, is expected to be close to unity. Here I argue that this mode of star formation is consistent with several models for globular clusters formation. Using simple arguments based on the observed number of globular cluster systems in the local universe and assuming that the oldest globular clusters formed before reionisation and had f_esc~1, I show that they produced enough ionising photons to reionise the IGM at z~6. I also enphasize that globular cluster formation might have been the dominant mode of star formation at redshifts from 6 to 12.
No associations
LandOfFree
Reionisation: the role of Globular Clusters 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 Reionisation: the role of Globular Clusters, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Reionisation: the role of Globular Clusters will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-556375