J/A+A/459/55 Narrow-band imaging of 5 Seyfert-1 galaxies (Bennert+, 2006)
Size and properties of the narrow-line region in Seyfert-1 galaxies
from spatially-resolved optical spectroscopy.
Bennert N., Jungwiert B., Komossa S., Haas M., Chini R.
<Astron. Astrophys. 459, 55 (2006)>
=2006A&A...459...55B 2006A&A...459...55B
ADC_Keywords: Galaxies, Seyfert ; Active gal. nuclei ; Photometry, narrow-band
Keywords: galaxies: active - galaxies: nuclei - galaxies: Seyfert
Abstract:
Spatially resolved emission-line spectroscopy is a powerful tool to
determine the physical conditions in the narrow-line region (NLR) of
active galactic nuclei (AGNs). We recently used optical long-slit
spectroscopy to study the NLRs of a sample of six Seyfert-2 galaxies.
We have shown that such an approach, in comparison to the commonly
used [OIII] narrow-band imaging alone, allows us to probe the size of
the NLR in terms of AGN photoionisation. Moreover, several physical
parameters of the NLR can be directly accessed. We here apply the same
methods to study the NLR of six Seyfert-1 galaxies and compare our
results to those of Seyfert-2 galaxies. We employ diagnostically
valuable emission-line ratios to determine the physical properties of
the NLR, including the core values and radial dependencies of density,
ionisation parameter, and reddening. Tracking the radial change of
emission-line ratios in diagnostic diagrams allows us to measure the
transition between AGN-like and HII-like line excitation, and thus we
are able to measure the size of the NLR. In the diagnostic diagrams,
we find a transition between line ratios falling in the AGN regime and
those typical for HII regions in two Seyfert-1 galaxies, thus
determining the size of the NLR. The central electron temperature and
ionisation parameter are in general higher in type-1 Seyferts than in
type 2s. In almost all cases, both electron density and ionisation
parameter decrease with radius. In general, the decrease is faster in
Seyfert-1 galaxies than in type 2s. In several objects, the gaseous
velocity distribution is characteristic for rotational motion in an
(inclined) emission-line disk in the centre. We give estimates of the
black hole masses. We discuss our findings in detail for each object.
Description:
Observed and reddening-corrected emission-line ratios relative
to Hβ are presented as a function of distance from the nucleus.
The uncertainties are in the range of ∼1-15%.
Objects:
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RA (2000) DE Designation(s)
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18 44 54.0 -62 21 53 FRL 51 = ESO 140- 43
05 19 35.6 -32 39 30 MCG-05-13-017 = ESO 362- 18
22 36 46.5 -12 32 43 Mrk 915 = MCG-02-57-023
01 23 54.2 -35 03 55 NGC 526A = ESO 352- 66
20 08 46.1 -61 05 55 NGC 6860 = ESO 143- 9
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 95 75 Observed and reddening-corrected emission-line
ratios relative to Hbeta for 5 galaxies
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See also:
J/A+A/456/953 : Narrow-band imaging of 6 Seyfert-2 galaxies (Bennert+, 2006)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- Name Galaxy name
15- 20 F6.2 arcsec r Distance from center (1)
22- 26 F5.2 --- OIIobs ? Observed line-ratio [OII] 3727 to Hbeta
28- 32 F5.2 --- OIIder ? Reddening-corrected line-ratio
[OIII] 3727 to Hbeta
34- 38 F5.2 --- OIIIobs Observed line-ratio [OIII] 5007 to Hbeta
40- 44 F5.2 --- OIIIder Reddening-corrected line-ratio
[OIII] 5007 to Hbeta
46- 49 F4.2 --- OIobs ?=- Observed line-ratio [OI] 6300 to Hbeta
51- 54 F4.2 --- OIder ?=- Reddening-corrected line-ratio
[OI] 6300 to Hbeta
56- 59 F4.2 --- HAobs Observed line-ratio Halpha to Hbeta
61- 64 F4.2 --- HAder Reddening-corrected line-ratio
Halpha to Hbeta
66- 70 F5.2 --- NIIobs Observed line-ratio [NII] 6583 to Hbeta
72- 75 F4.2 --- NIIder Reddening-corrected line-ratio
[NII] 6583 to Hbeta
77- 80 F4.2 --- SII1obs ?=- Observed line-ratio [SII] 6716 to Hbeta
82- 85 F4.2 --- SII1der ?=- Reddening-corrected line-ratio
[SII] 6716 to Hbeta
87- 90 F4.2 --- SII2obs ?=- Observed line-ratio [SII] 6731 to Hbeta
92- 95 F4.2 --- SII2der ?=- Reddening-corrected line-ratio
[SII] 6731 to Hbeta
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Note (1): Negative values correspond to spectra to the southeast of the
center, positive values correspond to spectra to the northwest.
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Acknowledgements: Nicola Benner, nicola.bennert(at)ucr.edu
References:
Bennert et al., NGC 1386, 2006A&A...446..919B 2006A&A...446..919B
(End) Patricia Vannier [CDS] 16-Jun-2006