SPECTROPOLARIMETRY OF THE CIRCINUS GALAXY

High quality 4500-6800 Angstrom spectropolarimetric observations of th e Circinus galaxy are reported. These show polarized and relatively br oad (FWHM similar to 3300 km/s) H alpha (as well as marginal H beta) a rising from a < 3'' (< 60 pc) region centered on the nucleus and coinc ident with the the peak of the narrow line region. Broad H alpha might also be present similar to 8'' (160 PC) SE from the nucleus and close to the dust lane, but the result is only marginal and should be verif ied by higher s/n data. The continuum is dominated by stellar emission with less than or equal to 3% contribution from the scattered AGN con tinuum, and all the light (i.e. all the stellar continuum and narrow l ines) is polarized, most probably by transmission through and scatteri ng by dust in the disk. The data are compatible with a simple model wh ere the scattered broad lines and AGN emission are quite polarized (P similar to 25%) but account for only 1% of the observed continuum. The scattered broad H alpha has an equivalent width W-lambda similar or e qual to 400 Angstrom, a flux similar to the narrow H alpha and a lumin osity similar or equal to 5 10(5) L-circle dot. Assuming an efficiency of 1% for the BLR mirror, the intrinsic luminosity of the broad Her i s roughly 5 10(7) L-circle dot and similar to 0.5% of the FIR luminosi ty, a ratio similar to those found in type 1 Seyferts. Specific predic tion for future observations are also presented.