The He II Gunn-Peterson Effect
Abstract
The UV background at a given redshift is representative of the starlight and QSO-light generated in earlier redshifts. It holds key information on the populations of stars and QSO's at high redshift. We have used observations of the He II Gunn-Peterson (G-P) effect along the line of sight to Q 0302-003 at z = 3.286 to constrain the spectral energy distribution of the UV background spectrum over the redshift range, z = 2.78 - 3.28. Assuming that stars have softer spectra than do QSO's, we used the softness of the UV background to discriminate between these two possible classes of ionizing sources. We find that stars appear to be significant contributors to the UV background at z > 3, but below z = 3, there is a hardening of the UV background suggestive of an increased contribution by QSO's.
- Publication:
-
The First Stars
- Pub Date:
- 2000
- DOI:
- 10.1007/10719504_61
- Bibcode:
- 2000fist.conf..323H