Open AccessNear‐infrared imaging polarimetry of Cygnus A
Author(s) -
Packham C.,
Young S.,
Hough J. H.,
Tadhunter C. N.,
Axon D. J.
Publication year - 1998
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.1998.01586.x
Subject(s) - physics , polarization (electrochemistry) , polarimetry , position angle , astrophysics , line of sight , scattering , degree of polarization , astronomy , infrared , wavelength , perpendicular , optics , galaxy , geometry , chemistry , mathematics
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 ∼2×10 44 erg s −1 .