Megamaser detection in Seyfert galaxies Virtual Observatory Resource

Authors
  1. Ramolla M.
  2. Haas M.
  3. Bennert V.N.
  4. Chini R.
  5. Published by
    CDS
Abstract

We revisit the relation between H_2_O maser detection rate and nuclear obscuration for a sample of 114 Seyfert galaxies, drawn from the CfA, 12um and IRAS F25/F60 catalogs. These sources have mid-infrared spectra from the Spitzer Space Telescope and they are searched for X-ray and [OIII] (5007{AA}) fluxes from the literature. We use the strength of the [OIV] (25.9um) emission line as tracer for the intrinsic AGN strength. After normalization by [OIV] the observed X-ray flux provides information about X-ray absorption. The distribution of X-ray/[OIV] flux ratios is significantly different for masers and non-masers: The maser detected Seyfert-2s (Sy 1.8-2.0) populate a distinct X-ray/[OIV] range which is, on average, about a factor four lower than the range of Seyfert-2 non-masers and about a factor of ten lower than the range of Seyfert-1s (Sy 1.0-1.5). Non-masers are almost equally distributed over the entire X-ray/[OIV] range. This provides evidence that high nuclear obscuration plays a crucial role for the probability of maser detection. Furthermore, after normalization with [OIV], we find a similar but weaker trend for the distribution of the maser detection rate with the absorption of the 7um dust continuum. This suggests that the obscuration of the 7um continuum occurs on larger spatial scales than that of the X-rays. Hence, in the AGN unified model, at moderate deviation from edge-on, the 7um dust absorption may occur without proportionate X-ray absorption. The absorption of [OIII] appears unrelated to maser detections. The failure to detect masers in obscured AGN is most likely due to insufficient observational sensitivity.

Keywords
  1. seyfert-galaxies
  2. astrophysical-masers
  3. radio-astronomy
  4. galaxies
  5. infrared-sources
  6. x-ray-sources
Bibliographic source Bibcode
2011A&A...530A.147R
See also HTML
https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/530/A147
IVOA Identifier IVOID
ivo://CDS.VizieR/J/A+A/530/A147
Document Object Identifer DOI
doi:10.26093/cds/vizier.35300147

Access

Web browser access HTML
http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/530/A147
https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/530/A147
http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/530/A147
IVOA Table Access TAP
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Run SQL-like queries with TAP-enabled clients (e.g., TOPCAT).
IVOA Cone Search SCS
For use with a cone search client (e.g., TOPCAT).
http://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/530/A147/table1?
https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/530/A147/table1?
http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/530/A147/table1?
IVOA Cone Search SCS
For use with a cone search client (e.g., TOPCAT).
http://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/530/A147/table3?
https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/530/A147/table3?
http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/530/A147/table3?

History

2011-05-26T09:30:45Z
Resource record created
2011-05-26T09:30:45Z
Created
2018-01-04T08:21:25Z
Updated

Contact

Name
CDS support team
Postal Address
CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France
E-Mail
cds-question@unistra.fr