Bibcode
Hatziminaoglou, E.; Fritz, J.; Franceschini, A.; Afonso-Luis, A.; Hernán-Caballero, A.; Pérez-Fournon, I.; Serjeant, S.; Lonsdale, C.; Oliver, S.; Rowan-Robinson, M.; Shupe, D.; Smith, H. E.; Surace, J.
Referencia bibliográfica
Monthly Notices of the Royal Astronomical Society, Volume 386, Issue 3, pp. 1252-1264.
Fecha de publicación:
5
2008
Número de citas
68
Número de citas referidas
65
Descripción
We derive the properties of dusty tori in active galactic nuclei from
the comparison of observed spectral energy distributions (SEDs) of SDSS
quasars and a precomputed grid of torus models. The observed SEDs
comprise SDSS photometry, Two-Micron All-Sky Survey J, H and K data,
whenever available, and mid-infrared (mid-IR) data from the Spitzer
Wide-area InfraRed Extragalactic Survey. The adopted model is that of
Fritz, Franceschini & Hatziminaoglou. The fit is performed by
standard χ2-minimization the model, however, can be a
multicomponent comprising a stellar and a starburst component, whenever
necessary. Models with low equatorial optical depth,
τ9.7, were allowed as well as `traditional' models with
τ9.7 >= 1.0, corresponding to AV >= 22
and the results were compared. Fits using high optical depth tori models
only produced dust more compactly distributed than in the configuration
where all τ9.7 models were permitted. Tori with
decreasing dust density with the distance from the centre were favoured
while there was no clear preference for models with or without angular
variation of the dust density. The computed outer radii of the tori are
of some tens of parsecs large but can reach, in a few cases, a few
hundreds of parsecs. The mass of dust, MDust, and IR
luminosity, LIR, integrated in the wavelength range between 1
and 1000 μm, do not show significant variations with redshift, once
the observational biases are taken into account. Objects with 70-μm
detections, representing 25 per cent of the sample, are studied
separately and the starburst contribution (whenever present) to the IR
luminosity can reach, in the most extreme but very few cases, 80 per
cent.
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Este grupo desarrolla varios proyectos extragalácticos en diferentes rangos del espectro electromagnético utilizando satélites y telescopios en tierra para estudiar la evolución cosmológica de las galaxias y el origen de la actividad nuclear en galaxias activas. En el aspecto instrumental, el grupo forma parte del consorcio internacional que ha
Ismael
Pérez Fournon