1. |
- Penston, M. V., et al.
(author)
-
The extended narrow line region of NGC 4151. I. Emission line ratios and their implications
- 1990
-
In: Astronomy and Astrophysics. - 0004-6361 .- 1432-0746. ; 236:1, s. 53-6262
-
Journal article (peer-reviewed)abstract
- The paper presents the first results from long-slit spectra of the Seyfert galaxy NGC 4151 which give average diagnostic ratios of weak lines in the extended narrow line region (ENLR) of that galaxy and the first direct density measurement in an ENLR. These data confirm that the ENLR is kinematically undisturbed gas in the disc of the galaxy which is illuminated by an ionizing continuum stronger by a factor of 13 than a power law interpolated between observed ultraviolet and X-ray fluxes. Explanations of this apparent excess include a hot thermal continuum, time variations and an anisotropic radiation field. The authors give reasons for favouring anisotropy which might be caused by shadowing by a thick accretion disc or by relativistic beaming. Shadowing by a molecular torus is unlikely, given the absence of an infrared signal from the reradiated flux absorbed by any torus. Anisotropy would have important implications for the bolometric luminosity and nature of active galactic nuclei
|
|
2. |
- Argo, M.K., et al.
(author)
-
OH in Messier 82
- 2004
-
In: in "Proceedings of the 7th European VLBI Network Symposium", Oct. 2004, Toledo, eds. R. Bachiller, F. Colomer, J.F. Desmurs, P. de Vicente, Obs. Astronómico Nacional, Alcala de Henares, Spain. ; , s. 151-152
-
Conference paper (other academic/artistic)
|
|
3. |
|
|
4. |
- Beswick, R.J., et al.
(author)
-
Sub-Arcsecond Imaging of the Radio Contiuum and HI Absorption in the Medusa Merger
- 2005
-
In: in Proceedings of The Evolution of Starbursts, Bad Honnef 16-20 August 2004, eds. S. Hüttemeister, E. Manthey, D. Bomans, K. Weis, AIP Conf. Proc., American Institute of Physics. - 0735402701 ; :783, s. pp. 263-270
-
Conference paper (peer-reviewed)
|
|
5. |
- Pedlar, A., et al.
(author)
-
OH Molecules and Masers in Messier 82
- 2004
-
In: in Proceedings of "The Neutral ISM in Starburst Galaxies", Marstrand, June 2003, eds. Aalto S., Huettemeister S., Pedlar A., Astronomical Society of the Pacific Conf. Series, San Francisco. - 1583811826 ; , s. 183-186
-
Conference paper (peer-reviewed)
|
|
6. |
|
|
7. |
|
|