Le. Kay et al., Spectropolarimetry of the luminous narrow-line Seyfert galaxies IRAS 20181-2244 and IRAS 13224-3809, ASTROPHYS J, 518(1), 1999, pp. 219-225
We observed the narrow-line Seyfert 1 galaxies IRAS 20181-2244 and IRAS 132
24-3809 with a new spectropolarimeter on the Ritchey-Chretien spectrograph
at the CTIO 4 m telescope. Previously it had been suggested that IRAS 20181
-2244 was a type 2 QSO and thus might contain an obscured broad-line region
that could be detected by the presence of broad Balmer lines in the polari
zed flux. We found the object to be polarized at about 2% and constant with
wavelength (unlike most narrow-line Seyfert 1 galaxies), but with no evide
nce of broad Balmer lines in polarized flux. The spectropolarimetry indicat
es that the scattering material is inside the broad-line region. IRAS 13224
-3809, notable for its high variability in X-ray and UV wavelengths, has a
low polarization consistent with a Galactic interstellar origin.