J/A+A/473/369 VISIR/VLT mid-infrared imaging of Seyfert nuclei (Haas+, 2007)
VISIR/VLT mid-infrared imaging of Seyfert nuclei: nuclear dust emission and
the Seyfert-2 dichotomy.
Haas M., Siebenmorgen R., Pantin E., Horst H., Smette A., Kaufl H.-U.,
Lagage P.-O., Chini R.
<Astron. Astrophys. 473, 369 (2007)>
=2007A&A...473..369H 2007A&A...473..369H
ADC_Keywords: Galaxies, Seyfert ; Galaxies, IR
Keywords: galaxies: nuclei - galaxies: active - galaxies: Seyfert -
infrared: galaxies
Abstract:
Half of the Seyfert-2 galaxies escaped detection of broad lines in
their polarised spectra observed so far. Some authors have suspected
that these non-HBLRs contain real Sy2 nuclei without intrinsic broad
line region hidden behind a dust torus. If this were true, then their
nuclear structure would fundamentally differ from that of Sy2s with
polarised broad lines: in particular, they would not be explained by
orientation-based AGN unification. Further arguments for two
physically different Sy2 populations have been derived from the warm
and cool IRAS F25/F60 ratios. These ratios, however, refer to the
entire host galaxies and are unsuitable to conclusively establish the
absence of a nuclear dust torus. Instead, a study of the Seyfert-2
dichotomy should be performed on the basis of nuclear properties only.
Here we present the first comparison between [OIII] λ 5007Å
and mid-infrared imaging at matching spatial resolution. The aim
is to check whether the nuclear dust emission scales with AGN
luminosity as traced by [OIII].
Description:
During the scientific verification phase of the VISIR instrument at
the ESO Very Large Telescope we observed 16 Sy1 and Sy2 nuclei at
11.25um with 0.35" spatial resolution (FWHM). We supplement
our observations with high-resolution 10-12um literature data of
58 Seyfert galaxies, for which spectroscopic or spectropolarimetric
information and far-infrared data are available.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 139 102 Source parameters
refs.dat 93 32 References
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See also:
VIII/65 : 1.4GHz NRAO VLA Sky Survey (NVSS) (Condon+ 1998)
VIII/71 : The FIRST Survey Catalog, Version 03Apr11 (Becker+ 2003)
II/156 : IRAS Faint Source Catalog |b|>10, Version 2.0 (Moshir+ 1989)
J/AJ/126/1607 : IRAS Revised Bright Galaxy Sample (Sanders+, 2003)
J/ApJS/98/477 : Optical spectral atlas of Seyfert nuclei (Ho+ 1995)
J/ApJS/112/315 : Spectroscopic parameters of Seyfert nuclei (Ho+ 1997)
J/ApJS/141/23 : JHK' imaging photometry of Seyfert 1. I. (Enya+, 2002)
J/ApJS/141/31 : JHK' imaging photometry of Seyfert 1. II. (Enya+, 2002)
J/MNRAS/366/480 : Emission-line properties of Seyfert 2 nuclei (Gu+, 2006)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 14 A14 --- Name Source name
18- 22 F5.1 Mpc Dist Distance (1)
26- 28 F3.1 --- SType Seyfert type
31- 34 A4 --- HBLR Hidden broad line region flag (2)
39 A1 --- l_F12umn Limit flag for 3-sigma upper limit in case
of non-detection
40- 44 I5 mJy F12umn Nuclear flux ay 12um
47- 48 I2 --- r_F12umn [1/13] References for nuclear 12um flux
51 A1 --- l_F12um Limit flag on F12um
52- 57 F6.3 Jy F12um Total flux density at 12um (3)
60 A1 --- l_F25um Limit flag on F25um
61- 66 F6.3 Jy F25um Total flux density at 25um (3)
70- 76 F7.3 Jy F60um Total flux density at 60um (3)
79 A1 --- l_F100um Limit flag on F100um
80- 86 F7.3 Jy F100um Total flux density at 100um (3)
90- 95 I6 10-19W/m2 [OIII] Line flux at [OIII]
100-104 I5 10-19W/m2 Hbeta ? Hbeta line flux
109-113 I5 10-19W/m2 Halpha ? Halpha line flux
118-119 I2 --- r_[OIII] [21/39] reference for line fluxes
123-128 F6.1 mJy Frad1 ? FIRST (VIII/71) flux at 1.4GHz
132-139 F8.1 mJy Frad2 ? NVSS (VIII/65) flux at 1.4GHz
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Note (1): We used a Lambda cosmology with H0=71km/s/Mpc,
Omegamatter=0.27 and OmegaLambda=0.73.
Note (2): HBLR flag as follows:
yes = hidden broad line region
no = Not hidden broad line region
? = unknown
NLS1 = narrow line Seyfert-1
References are: Heisler et al. (1997Natur.385..700H 1997Natur.385..700H), Lumsden et al.
(2001MNRAS.327..459L 2001MNRAS.327..459L, 2001MNRAS.328L..32L 2001MNRAS.328L..32L, 2004MNRAS.348.1451L 2004MNRAS.348.1451L), Moran
et al. (2000ApJ...540L..73M 2000ApJ...540L..73M, 2001ApJ...556L..75M 2001ApJ...556L..75M, 2007, ASP, in press
astroph/070369), Tran (2003ApJ...583..632T 2003ApJ...583..632T), see compilation by Gu &
Huang (2002ApJ...579..205G 2002ApJ...579..205G).
Note (3): IRAS photometry was taken from NED, mostly Sanders et al. (2003,
Cat. J/AJ/126/1607), if available, otherwise from Faint Source
Catalog (Cat. II/156), the source of photometry had no significant
effect on the analysed quantities F25/F60 or nuclear/galactic F12.
For some sources the photometry was estimated/improved: for NGC3362,
NGC5252, NGC5283, Mrk334, IRAS01527+0622 from ISO (Perez Garcia &
Rodriguez Espinosa, 2001ApJ...557...39P 2001ApJ...557...39P), and for Mrk897, NGC2992,
NGC3081, NGC3783, NGC3786, NGC5427, NGC7213, NGC7682 from Spitzer data
(this work).
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Ref Reference number
4- 22 A19 --- BibCode BibCode
24- 46 A23 --- Aut Author's name
48- 93 A46 --- Com Comments
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Acknowledgements:
Martin Haas, haas(at)astro.rub.de
(End) Patricia Vannier [CDS] 18-Sep-2007