Abstract
THE different kinds of active galactic nuclei (AGNs) and quasars may be fundamentally similar, and owe their observed differences to anisotropy in the distribution of their emitted radiation: apparently different objects may then be the same thing seen from different viewpoints. In particular, it has been proposed that narrow-line Seyfert 2 galaxies are Seyfert 1 galaxies for which the broad-line and continuum emitting regions are hidden by obscuring material along our line of sight1,2 Here we present narrow-band imaging observations of the Seyfert 2 galaxy NGC5252 which strongly support such unifying hypotheses. Images in the light of the [O III] line at λ = 5,007 Å reveal a sharply defined bi-conical structure extending to a maximum radius of ∼33 kpc (H0 = 50 km s−1 Mpc−11) along the radio-emission axis. This is just the type of structure expected if the ionizing-radiation field from the nucleus is anisotropic. A map of the ratio of the [O III] and Hα lines shows a central band perpendicular to the cones that we identify as the disk or torus responsible for collimating the radiation field.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Lawrence, A. & Elvis, M. Astrophys. J. 256, 410–426 (1982).
Antonucci, R. R. J. & Miller, J. S. Astrophys. J. 297, 621–623 (1985).
Unger, S. W. et al. Mon. Not. R. astr. Soc. 228, 671–679 (1987).
Wilson, A. S., Ward, M. J. & Haniff, C. A. Astrophys. J. 334, 121–129 (1988).
van Breugel, W., Miley, G., Heckman, T., Butcher, H. & Bridle, A. Astrophys. J. 290, 496–516 (1985).
Tadhunter, C. N. et al. Mon. Not. R. astr. Soc. 235, 403–423 (1988).
Netzer, H. Mon. Not. R. astr. Soc. 216, 63–78 (1985).
Orr, M. J. L. & Browne, I. W. A. Mon. Not. R. astr. Soc. 200, 1067–1080 (1982).
Jackson, N., Browne, I. W. A., Murphy, D. W. & Saikia, D. J. Nature 338, 485–487 (1989).
Robinson, A., Binette, L., Fosbury, R. A. E. & Tadhunter, C. N. Mon. Not. R. astr. Soc. 227, 97–114 (1987).
Gottesman, S. T. & Harwarden, T. G. Mon. Not. R. astr. Soc. 219, 759–775 (1986).
Pérez, E., González-Delgado, R. M., Tadhunter, C. N. & Tsvetanov, Z. Mon. Not. R. astr. Soc. (in the press).
Meurs, E. J. A. Astrophys. & Space. Sci. 140, 353–358 (1988).
Cheng, F. Z., Danese, L., de Zotti, G. & Fanceschini, A. Mon. Not. R. astr. Soc. 212, 857–871 (1985).
Véron-Cetty, M.-P. Astr. Astrophys. Suppl. 58, 665.
Stockton, A. & McKenty, J. W. Astrophys. J. 316, 584–596 (1987).
Tadhunter, C. N. thesis, Univ. Sussex (1986).
Baum, S. A., Heckman, T. M., Bridle, A., van Breugel, W. J. M. & Miley, G. K. Astrophys. J. Suppl. 68, 643–714 (1989).
Baum, S. A. & Heckman, T. M. Astrophys. J. (in the press).
Barthel, P. D. Astrophys. J. 336, 606–611 (1989).
Nilson, P. Uppsala General Catalogue of Galaxies Series V: A, vol. 1 (Roy. Soc. Sci., Uppsala, 1973).
Edelson, R. A. Astrophys. J. 313, 651–661 (1987).
The MIDAS Users' Guide ESO Operating Manual No. 1 (European Southern Observatory, 1988).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Tadhunter, C., Tsvetanov, Z. Anisotropic ionizing radiation in NGC5252. Nature 341, 422–424 (1989). https://doi.org/10.1038/341422a0
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1038/341422a0
This article is cited by
-
The glowing dusty heart of a hidden quasar
Nature (2022)
-
Radio AGN in the local universe: unification, triggering and evolution
The Astronomy and Astrophysics Review (2016)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.
