On the origin of de-polarization in CB54

Abstract

We present polarimetric observations of the Bok globule CB54 in the far-infrared via SOFIA/HAWC+ bands D (154 (Formula presented.) m) and E (214 (Formula presented.) m). We detect polarization with mean polarization degrees of (Formula presented.) (Formula presented.) 5.4 (Formula presented.) and (Formula presented.) (Formula presented.) 5.4 (Formula presented.) at 154 and 214 (Formula presented.) m, respectively. The polarization degree decreases toward the inner region of CB54, revealing a “polarization hole”. This finding can be explained by the impact of dichroic absorption counteracting the effect of polarized emission. The same effect allows us to explain the observed wavelength-dependent orientation of the linear polarization in the dense, central region of CB54. The polarization pattern appears uniform at core scales but un-ordered at larger scales—similar to what was found in previous studies of this object. The mean polarization angle amounts to (Formula presented.) = 62.4 (Formula presented.) 44.5° and (Formula presented.) = (Formula presented.) 60.0° at 154 and 214 (Formula presented.) m, respectively