We present high-sensitivity ( \sigma _ { I } \sim 0.2 - 0.5 mJy , \sigma _ { QU } \sim 0.05 mJy ) , high-resolution ( \sim 0 \farcs 12 - 0 \farcs 2 ) observations of polarized 872 \mu m dust emission from the young multiple system VLA 1623 in \rho Ophiuchus and the protostar L1527 in Taurus .
We detect the circumstellar material of VLA 1623A , the extended Keplerian disk surrounding VLA 1623A which we call VLA 1623CBdisk , VLA 1623B , VLA 1623W , and L1527 strongly in the polarized emission , at the \sim 1 - 3 \% level .
We spatially resolve VLA 1623A into two sources , VLA 1623Aa and VLA 1623Ab , separated by \sim 30 au and located within a cavity of radius \sim 50 au within the circumbinary Keplerian disk , as well as the edge-on disk of VLA 1623W .
The polarization angle of the emission is uniform across each protostellar source and nearly coincides with each disk ’ s minor axis .
The offsets between the minor axis and the polarization angle are not uniformly distributed at the P \lesssim 2 \times 10 ^ { -4 } level .
The circumbinary disk surrounding VLA 1623Aab is azimuthally symmetrically polarized .
Each compact source ’ s emission is partially optically thick ( \tau \gtrsim 1 ) at 872 \mu m , complicating interpretations of polarization involving aligned grains .
We find evidence against alignment by radiative flux in each source , particularly in the edge-on VLA 1623W and L1527 .
We detect astrometric offsets between the polarized emission and the total intensity in VLA 1623Aa , VLA 1623Ab , and VLA 1623B , as predicted if self-scattering in the optically thick limit operates .
We conclude that self-scattering is likely responsible for disk-scale polarization at 872 \mu m in these systems .