ACTIVE GALACTIV NUCLEIN IN THE INFRARED
Institut d'Astrophysique de Paris
Jeudi 27/09/2007, 11:00
Bât 709, p 220 (salle Godunov), CEA Saclay, Orme des Merisiers
SEMINAIRE régulier du Service d’Astrophysique
Active Galactic Nuclei in the infrared: identification, energetic and
properties of the obscuring matter
Mari Polletta (Institut d'Astrophysique de Paris)
Using multi-wavelength data from the largest Spitzer legacy project, SWIRE,
the properties (spectral energy distributions, redshifts and luminosities)
of Active Galactic Nuclei (AGN) are investigated. The AGN content among
infrared populations is estimated and compared with previous findings and models.
We show that a mid-infrared selection can efficiently find the
long-sought obscured and luminous AGNs at high redshifts.
We present a remarkable sample of extremely luminous and heavily
obscured AGNs at z~2 selected in the mid-infrared. Their spectral energy
distributions and infrared spectra are modeled with clumpy torus models, and the
properties of their obscuring matter are constrained. Large far-infrared
luminosities, above the predictions of the torus models, are measured in a sub-set of these
obscured AGNs, implying extreme star formation rates if powered by a starburst.
The implications of our results on current AGN models and predictions
for future Herschel observations of obscured and luminous AGNs are discussed.