XXIVth IAP Colloquium

Far away : light in the young universe at redshift beyond three

Monday July 7 to Friday July 11, 2008

List of DEHARVENG's Presentation(s) ( Updated 20/01/2011 11:57:04 )

Precise if your presentation is oral or a poster : oral
Title of your presentation : Cosmic evolution of the Ly-alpha luminosity density

The significant number of Lyman alpha emitting galaxies observed at high redshifts and recently at low z with GALEX provides now a picture of
the evolution of Lyman alpha emission over a large range of redshift. The GALEX sample improves over previously known nearby emitters by its statistical significance. Since Ly-a emission is affected by resonant scattering, the Ly-a evolution is appreciated by comparison with the evolution of massive star. We present a comparison in terms of luminosity density (LD).
From z=0 to z about 3, the Ly-alpha LD increases slightly faster than the UV LD, suggesting a possible increase of the average Ly-a escape fraction as a function of redshift. Beyond z=3, if the UV LD declines as shown by some authors, there is again a slight increase of the average Ly-a escape up to z=6. At the epoch of reionization, the LD comparison is probably less appropriate than the direct comparison of Ly-a LFs for a search of increased IGM opacity.

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