UV radiation from quasars

Schiminovich came down for the day and we worked on the ionizing radiation in the Universe from quasars, as a function of redshift. We are making a direct measurement using GALEX, but also using SDSS to tell us where to photometer the GALEX data, which is too shallow to detect many of the quasars of interest. We discussed—and Schiminovich made some progress on incorporating—incompleteness information from (imperfect) quasar selection.


  1. Not sure how high up you are going in z, but watch out for SDSS selection effects at z~3.4, since it's biased *towards* qsos having lyman limits

  2. Excellent point, which I only understood for the first time this summer. I think we will have to build a model of the IGM absorption. That model might end up being trivial!