Scientific Seminars

What are X-ray observations of optically selected Type 2 quasars telling us?

Christian Vignali
Dipartimento di Astronomia, Universita' degli Studi di Bologna

2006-04-12    14:00    Brera -

Recent X-ray surveys with Chandra and XMM-Newton have discovered many Type 2 quasars, the long-sought after "big cousins" of local Seyfert 2 galaxies. By contrast, till few years ago the number of these quasars from optical surveys was extremely limited, casting some doubts on the efficiency of these surveys in detecting luminous, high-ionization, narrow emission-line AGN. Here we present the Chandra and XMM-Newton spectral results of optically selected Type 2 quasar candidates drawn out from two large-area, ground-based surveys, the Sloan Digital Sky Survey and the Palomar Sky Survey.