Bibcode
Hatziminaoglou, E.; Perez-Fournon, I.; Rowan-Robinson, M.; Babbedge, T.; Lonsdale, C. J.; Fritz, J.; Afonso-Luis, A.; Hernan-Caballero, A.; SWIRE Team
Referencia bibliográfica
American Astronomical Society Meeting 207, #63.02; Bulletin of the American Astronomical Society, Vol. 37, p.1246
Fecha de publicación:
12
2005
Número de citas
2
Número de citas referidas
2
Descripción
SWIRE's wide-area multi-band coverage offers unprecedented opportunities
for constructing large, unbiased AGN samples and for studying their
cosmological evolution and physical properties. Here we present a
collection of SWIRE results, namely on the infrared (IR) luminosity
functions and on the tori characteristics of type-1 AGN. Type-1 AGN show
clear signs of luminosity evolution out to z ˜ 3 but also indicate
some density evolution. This trend stops at higher redshifts suggesting
that the epoch of peak formation and/or fueling has been reached. The 24
micron luminosity function shows stronger evolution than the IRAC bands.
Results from a simple template fitting of the entire SWIRE sample
indicate a high proportion of galaxies whose mid-IR SEDs are fitted by
an AGN dust torus template (around one third). Of these only a small
fraction are type-1 AGN according to the optical-near-IR template
fitting, whereas the remaining are either type-2 AGN or Seyfert
galaxies. The implied dust covering factor of more than 75% is much
higher than that inferred for bright optically selected quasars. More
detailed modeling of the torus surrounding the AGN can greatly benefit
from SWIRE data. The IRAC and MIPS 24 micron data points impose strong
constraints on the torus model parameters, such as the torus size,
density law, and optical depth. Models with intermediate outer radii and
density decreasing with increasing distance from the center are favored,
while low optical depths are not ruled out.