552 citations · 16.5k across the 268 of their papers we have counts for
8 papers · 2 filters
Accretion Disk Instabilities, CDM models and their role in Quasar Evolution
E. Hatziminaoglou, A. Siemiginowska, M. Elvis
We have developed a consistent analytical model to describe the observed evolution of the quasar luminosity function. Our model combines black hole mass distributions based on the…
Blank Field X-Ray Sources
Ilaria Cagnoni, Annalisa Celotti, Martin Elvis +2
The X-ray sky is not as well known as is sometimes thought. We report on our search of minority populations (Kim & Elvis 1999). One of the most intriguing is that of `blank field s…
150 keV Emission from PKS2149-306 with BeppoSAX
Martin Elvis, Fabrizio Fiore, Aneta Siemiginowska +3
A BeppoSAX observation of the z=2.34 quasar PKS2149-306 produced a strong signal in the high energy PDS instrument up to a maximum observed energy of nearly 50 keV, 150 keV in the…
BeppoSAX broad-band observations of low-redshift quasars: Spectral curvature and iron K_alpha lines
T. Mineo, F. Fiore, A. Laor +7
We present results from BeppoSAX observations of 10 low redshift quasars. The quasars are part of the Laor et al. (1997) sample of 23 optically selected PG quasars with redshift <0…
An exploratory study of the hard X-ray variability properties of PG quasars with RXTE
M. Guainazzi, F. Fiore, E. Giallongo +3
We have monitored with the RXTE PCA the variability pattern of the 2-20 keV flux in four PG quasars (QSOs) from the Laor et al. (1994) sample. Six observations of each target at re…
Thomson Thick X-ray Absorption in a Broad Absorption Line Quasar PG0946+301
S. Mathur, P. J. Green, N. Arav +14
We present a deep ASCA observation of a Broad Absorption Line Quasar (BALQSO) PG0946+301. The source was clearly detected in one of the gas imaging spectrometers, but not in any ot…
Infrared Properties of High Redshift and X-ray Selected AGN Samples
Belinda J. Wilkes, Eric J. Hooper, Kim K. McLeod +7
The NASA/ISO Key Project on active galactic nuclei (AGN) seeks to better understand the broad-band spectral energy distributions (SEDs) of these sources from radio to X-rays, with…
A Long Observation of NGC 5548 by BeppoSAX: the High Energy Cut-off, Intrinsic Spectral Variability and a Truly Warm Absorber
F. Nicastro, L. Piro, A. De Rosa +11
NGC 5548 was observed by BeppoSAX in a single long (8 day) observation from 0.2 to 200 keV. We find (1) the spectral variation of the source is produced by a change of the intrinsi…