  Planets and minor bodies such as asteroids, Kuiper-belt objects and comets
are integral components of a planetary system. Interactions among them leave
clues about the formation process of a planetary system. The signature of such
interactions is most prominent through observations of its debris disk at
millimeter wavelengths where emission is dominated by the population of large
grains that stay close to their parent bodies. Here we present ALMA 1.3 mm
observations of HD 95086, a young early-type star that hosts a directly imaged
giant planet b and a massive debris disk with both asteroid- and Kuiper-belt
analogs. The location of the Kuiper-belt analog is resolved for the first time.
The system can be depicted as a broad ($\Delta R/R \sim$0.84), inclined
(30\arcdeg$\pm$3\arcdeg) ring with millimeter emission peaked at 200$\pm$6 au
from the star. The 1.3 mm disk emission is consistent with a broad disk with
sharp boundaries from 106$\pm$6 to 320$\pm$20 au with a surface density
distribution described by a power law with an index of --0.5$\pm$0.2. Our deep
ALMA map also reveals a bright source located near the edge of the ring, whose
brightness at 1.3 mm and potential spectral energy distribution are consistent
with it being a luminous star-forming galaxy at high redshift. We set
constraints on the orbital properties of planet b assuming co-planarity with
the observed disk.
