J/A+A/583/A120 AGN torus models. SED library (Siebenmorgen+, 2015)
Self-consistent two-phase AGN torus models. SED library for observers.
Siebenmorgen R., Heymann F., Efstathiou A.
<Astron. Astrophys. 583, A120 (2015)>
=2015A&A...583A.120S 2015A&A...583A.120S (SIMBAD/NED BibCode)
ADC_Keywords: Models ; Active gal. nuclei ; Energy distributions
Keywords: galaxies: active - radiative transfer - galaxies: quasars: general -
galaxies: Seyfert - methods: numerical -
astronomical databases: miscellaneous
Abstract:
We assume that dust near active galactic nuclei (AGNs) is distributed
in a torus-like geometry, which can be described as a clumpy medium or
a homogeneous disk, or as a combination of the two (i.e. a two-phase
medium). The dust particles considered are fluffy and have higher
submillimeter emissivities than grains in the diffuse interstellar
medium. The dust-photon interaction is treated in a fully
self-consistent three-dimensional radiative transfer code. We provide
an AGN library of spectral energy distributions (SEDs). Its purpose is
to quickly obtain estimates of the basic parameters of the AGNs, such
as the intrinsic luminosity of the central source, the viewing angle,
the inner radius, the volume filling factor and optical depth of the
clouds, and the optical depth of the disk midplane, and to predict the
flux at yet unobserved wavelengths. The procedure is simple and
consists of finding an element in the library that matches the
observations. We discuss the general properties of the models and in
particular the 10um silicate band. The AGN library accounts well
for the observed scatter of the feature strengths and wavelengths of
the peak emission. AGN extinction curves are discussed and we find
that there is no direct one-to-one link between the observed
extinction and the wavelength dependence of the dust cross sections.
We show that objects in the library cover the observed range of
mid-infrared colors of known AGNs. The validity of the approach is
demonstrated by matching the SEDs of a number of representative
objects: Four Seyferts and two quasars for which we present new
Herschel photometry, two radio galaxies, and one hyperluminous
infrared galaxy. Strikingly, for the five luminous objects we find
that pure AGN models fit the SED without needing to postulate
starburst activity.
Description:
There are 3600 ASCII tables files in two columns format. The first is
the wavelength in microns, the second column is the flux in Jy. SEDs
are computed for AGNs at a distance of 50Mpc and a luminosity of
1011L☉. The file names include the five basic model
parameters:
a) th: The viewing angle corresponding to bins at 86, 80, 73, 67, 60,
52, 43, 33, and 19 degree measured from the pole (z-axis).
thx= th1 ,.., th9
b) R : The inner radius of the dusty torus.
R= 300, 514, 772, 1000, 1545 in units: (10^15 cm)
c) Vc: The cloud volume filling factor.
Vc= 1.5, 7.7, 38.5, 77.7 (%).
d) Ac: The optical depth (in V) of the individual clouds.
Ac= 0, 4.5, 13.5, 45.
e) Ad: The optical depth (in V) of the disk midplane.
Ad= 0, 30, 100, 300, 1000.
Example: File notation.
RxxxxVcxxxAcxxxx_Adxxxx.thx
R1545Vc777Ac0135_Ad1000.th9
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
list.dat 53 3600 List of SED files
sedlib/* . 3600 Individual SED files
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 10+15cm R Inner radius of the dusty torus
6- 9 F4.1 % Vc Cloud volume filling factor
11- 15 F5.1 --- Ac Optical depth (in V) of the individual cloud
17- 20 I4 --- Ad Optical depth (in V) of the disk midplane
22- 23 I2 deg th Central value of bin viewing angle measured
from the pole (z-axis)
25- 53 A29 --- FileName Name of the SED file in subdirectory sedlib
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Byte-by-byte Description of file: sedlib/*
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 F13.9 um lambda Wavelength
15- 25 E11.7 Jy Flux Flux
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Acknowledgements:
Ralf Siebenmorgen, rsiebenm(at)eso.org
(End) Patricia Vannier [CDS] 28-Aug-2015