We present high-resolution 5 au imaging of the dust polarization in the HL Tau circumstellar disk at 870 microns using ALMA. With well over 1000 independently sampled polarization angles measured at this resolution, HL Tau is the most spatially sampled circumstellar disk in polarization to date. The polarized emission fraction is often <1% in the rings, while in the gaps reaching levels of about ~3%, i.e. the most highly polarized emission is in the gaps, not the rings. Although most of the disk has uniform polarization, there is considerable variation in the disk, especially in the gaps. The polarized emission is mostly consistent with scattering, but there exists an additional component that may be due to emission from aligned grains. We also detect a new 8th gap in the disk from the deep Stokes I continuum. In addition, we present new multi-wavelength polarization observations at 30 au resolution for Bands 4, 5, and 7. The Bands 4 and 5 polarization patterns also continue the transition from uniform polarization parallel to the disk minor axis to an elliptically oriented distribution.
[Poster PDF File]