5 papers
Type II quasar candidates in the Sloan Digital Sky Survey: evidence for X-ray obscuration
C. Vignali, D. M. Alexander, A. Comastri
Recent X-ray surveys with Chandra and XMM-Newton have found several genuine Type II quasars, the long sought-after population of high-luminosity (high-redshift) Seyfert 2 galaxies,…
The ROSAT North Ecliptic Pole Survey: The Optical Identifications
I. M. Gioia, J. P. Henry, C. R. Mullis +4
The X-ray data around the North Ecliptic Pole (NEP) of the ROSAT All Sky Survey have been used to construct a contiguous area survey consisting of a sample of 445 individual X-ray…
The Galaxy Luminosity and Selection Functions of the NOG Sample
C. Marinoni, G. Giuricin, B. Costantini +1
In order to map the galaxy density field on small scales in the local universe, we use the Nearby Optical Galaxy (NOG) sample, which is currently one of the largest, nearly complet…
Peculiar Motions and the Galaxy Density Field
C. Marinoni, G. Giuricin, B. Costantini +1
We use an all--sky, complete sample of nearby galaxies, extracted from the LEDA data base, to map the optical galaxy density field in the nearby universe. In order to determine thi…
GOHSS: a Fibre-fed Multiobject NIR Spectrograph for the Italian Galileo Telescope
R. Scaramella, E. Cascone, F. Cortecchia +6
We present the concept and preliminary design of the Galileo OH Subtracted Spectrograph [GOHSS], a multifibre NIR spectrograph for faint objects. The instrument represents a collab…