Now showing items 1-8 of 8

    • Constraints on the nuclear emission of the Circinus galaxy: The torus 

      Ruiz, Milagros; Efstathiou, Andreas; Alexander, David M.; James H. Hough, James (2001-08-11)
      In the context of the unified model of Seyfert galaxies, we use observations from the literature and a radiative transfer model to investigate the near-IR to mm emission produced by the presumed torus in the Circinus galaxy, ...
    • Magnetic fields in discs: What can be learned from infrared and mm polarimetry? 

      Aitken, David K.; Efstathiou, Andreas; McCall, Alan; James H. Hough, James (2002-01-21)
      Polarimetric imaging in the infrared and submm offers the possibility of identifying magnetic field configurations in astronomical objects. To test this conjecture a set of field geometries within internally heated discs ...
    • Observations and a model for the infrared continuum of Centaurus A 

      Alexander, David M.; Efstathiou, Andreas; James H. Hough, James; Aitken, David K.; Lutz, Dieter; Roche, Patrick F.; Sturm, Eckhard (1999-11-21)
      We present ISOSWS, ISOPHOT_S and 8-13 μm observations of Centaurus A which show prominent PAH and silicate features. These and other data are used to construct a model for the infrared continuum. We find that, in a small ...
    • Polarimetry and modelling of narrow-line active galaxies 

      Young, Stuart; James H. Hough, James; Efstathiou, Andreas; Wills, Beverley J.; Bailey, Jeremy A.; Ward, Martin J.; Axon, David J. (1996-01-01)
      We present optical spectropolarimetry along with optical and infrared broad-band filter polarimetry of selected warm [f(25 μm)/f(60 μm) ≥ 0.3] IRAS galaxies and other known Seyfert 2 galaxies. Broad lines in polarized flux ...
    • Polarimetry and the torus 

      James H. Hough, James; Young, Stuart; Efstathiou, Andreas (1996-01-01)
      While the torus plays an obvious role in blocking direct light, and thus increasing the observed polarization from scattering, its role in directly producing polarized flux is less clear. Contributions to the infrared ...
    • Polarization due to dichroic absorption and emission by aligned grains in dusty discs 

      Efstathiou, Andreas; McCall, Alan; James H. Hough, James (1997-01-01)
      We present a method for calculating the infrared polarization due to absorption and emission by aligned grains distributed in a disc or a torus. The temperature distribution in the torus is calculated with the axially ...
    • Scattered broad optical lines in the polarized flux spectrum of the FR II galaxy 3C 321 

      Young, Stuart; James H. Hough, James; Efstathiou, Andreas; Wills, Beverley J.; Axon, David J.; Bailey, Jeremy A.; Ward, Martin J. (1996-01-01)
      We present optical/infrared broad-band filter polarimetry and optical spectropolarimetry of the powerful FR II galaxy 3C 321. The latter observations reveal a scattered broad component to the Hα emission line, detectable ...
    • The nuclear torus in the active galaxy NGC 1068 

      Young, Stuart; Packham, Christopher C.; James H. Hough, James; Efstathiou, Andreas (1996-01-01)
      We present near-infrared polarized images of the active galaxy NGC 1068. At these wavelengths, the counter-cone is observed in scattered light. At H (1.64 μm) we detect an absorption band across the counter-cone, which we ...