Near-infrared imaging polarimetry of Cygnus A |
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| Authors: | C. Packham,S. Young,J. H. Hough,C. N. Tadhunter,& D. J. Axon |
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| Affiliation: | Department of Physical Sciences, University of Hertfordshire, Hatfield, Herfordshire AL10 9AB,;Department of Physics, University of Sheffield, Sheffield S3 7RH,;Nuffield Radio Astronomy Laboratory, University of Manchester, Jodrell Bank, Macclesfield, Cheshire SK11 9DR |
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| Abstract: | We present a 2.2-μm polarization image of the nuclear regions of Cygnus A. The degree of polarization in the central 1 arcsec is (4.1±0.50) per cent, at a position angle of (23.6±3.6)°, approximately perpendicular to the axis of the radio jet.
Modelling of the results suggests that at this wavelength the polarization along the line of sight to the central source is most likely produced by dichroism, through an A v∼40 mag, with the polarization in surrounding regions produced by scattering. For this model, the K -band luminosity of the central source is calculated to be ∼2×1044 erg s−1. |
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| Keywords: | polarization methods: observational techniques: polarimetric galaxies: individual: Cygnus A galaxies: nuclei infrared: galaxies. |
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