  In the past decade, ALMA observations of protoplanetary disks revealed
various substructures including gaps and rings. Their origin may be probed
through statistical studies on the physical properties of the substructures. We
present the analyses of archival ALMA Band 6 continuum data of 43 disks (39
Class II and 4 Herbig Ae) in the Taurus-Auriga region. We employ a novel 2D
super-resolution imaging technique based on sparse modeling to obtain images
with high fidelity and spatial resolution. As a result, we have obtained images
with spatial resolutions comparable to a few au ($0''.02 - 0''.1$), which is
two to three times better than conventional CLEAN methods. All dust disks are
spatially resolved, with the radii ranging from 8 to 238 au with a median
radius of 45 au. Half of the disks harbor clear gap structures, whose radial
locations show a bimodal distribution with peaks at $\lesssim20$ au and
$\gtrsim30$ au. We also see structures indicating weak gaps at all the radii in
the disk. We find that the widths of these gaps increase with their depths,
which is consistent with the model of planet-disk interactions. The inferred
planet mass-orbital radius distribution indicates that the planet distribution
is analogous to our Solar System. However, planets with Neptune mass or lower
may exist in all the radii.
