Optical and near-infrared polarimetry of the infrared luminous galaxy IRAS 23060 + 0505

Abstract

Optical and NIR polarization and flux density measurements of the IR luminous galaxy IRAS 23060 + 0505 are presented. The flux density in an 8-arcsec diameter aperture follows an approximate power law, while the polarized flux density spectrum steepens from a spectral index of 2.48 in the NIR to 6.0 shortward of 0.8 microns. The wavelength dependence of degree of polarization is unusual, rising very steeply from 1 to 2 percent in the blue to a level of about 8 percent in the I band and then falling slowly through the NIR. A number of different models have been developed as an aid to interpreting the wavelength dependence of polarization and flux density observed for 23060 + 0505. Scattering of radiation from a continuum source largely obscured from the direct sight is the most likely explanation for the observed polarization. 44 refs.