Surveys and the Blazar Parameter Space
Perlman, E. S. ; Padovani, P. ; Landt, H. ; ...Giommi, P. ; et al.
Jan - 2000

journal : PREPRINT
type: Article Journal

Abstract
The rareness of blazars, combined with the previous history of relatively shallow, single-band surveys, has dramatically colored our perception of these objects. Despite a quarter-century of research, it is not at all clear whether current samples can be combined to give us a relatively unbiased view of blazar properties, or whether they present a view so heavily affected by biases inherent in single-band surveys that a synthesis is impossible. We will use the coverage of X-ray/radio flux space for existing surveys to assess their biases. Only new, deeper blazar surveys approach the level needed in depth and coverage of parameter space to give us a less biased view of blazars. These surveys have drastically increased our knowledge of blazars properties. We will specifically review the discovery of ``blue blazars, objects with broad emission lines but broadband spectral characteristics similar to HBL BL Lac objects.

keywords : Astrophysics,Giommi Paolo: ASI author