Issue |
A&A
Volume 366, Number 2, February I 2001
|
|
---|---|---|
Page(s) | 407 - 417 | |
Section | Astrophysical processes | |
DOI | https://doi.org/10.1051/0004-6361:20000105 | |
Published online | 15 February 2001 |
Testing current synthesis models of the X-ray background
1
Dipartimento di Astronomia e Scienza dello Spazio, Università di Firenze, Largo E. Fermi 5, 50125 Firenze, Italy e-mail: gilli@arcetri.astro.it
2
Astrophysikalisches Institut Potsdam, An der Sternwarte 16, 14482 Potsdam, Germany e-mail: ghasinger@aip.de
3
Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125 Firenze, Italy e-mail: salvati@arcetri.astro.it
R. Gilli
Received:
3
October
2000
Accepted:
14
November
2000
We present synthesis models of the X-ray background where
the available X-ray observational constraints are used to
derive information on the AGN population properties.
We show the need for luminous X-ray absorbed AGNs, the QSO2s,
in reproducing the 2-10 keV source counts at relatively bright fluxes.
We compare a model where the evolution of absorbed AGNs
is faster than that of unabsorbed ones, with a standard model where
absorbed and unabsorbed AGNs evolve at the same rate. It is found
that an increase by a factor of ∼ 2 from to
in the ratio between absorbed and unabsorbed AGNs would
provide a significant improvement in the data description.
Finally, we make predictions on the AGNs to be observed in deep X-ray
surveys which contain information on the AGN space density at high redshift.
Key words: X / rays: galaxies / galaxies: nuclei / cosmology: diffuse radiation
© ESO, 2001
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