We present ALMA observations of the 0.88Â millimeter dust continuum , ^ { 13 } CO , and C ^ { 18 } O J=3-2 line emission of the circumbinary disk HDÂ 142527 at a spatial resolution of \sim 0.25 \arcsec .
This system is characterized by a large central cavity of roughly 120 AU in radius , and asymmetric dust and gas emission .
By comparing the observations with theoretical models , we find that the azimuthal variations in gas and dust density reach a contrast of 54 for dust grains and 3.75 for CO molecules , with an extreme gas-to-dust ratio of 1.7 on the dust crescent .
We point out that caution is required in interpreting continuum subtracted maps of the line emission as this process might result in removing a large fraction of the line emission .
Radially , we find that both the gas and dust surface densities can be described by Gaussians , centered at the same disk radius , and with gas profiles wider than for the dust .
These results strongly support a scenario in which millimeter dust grains are radially and azimuthally trapped toward the center of a gas pressure bump .
Finally , our observations reveal a compact source of continuum and CO emission inside the dust depleted cavity at \sim 50 AU from the primary star .
The kinematics of the CO emission from this region is different from that expected from material in Keplerian rotation around the binary system , and might instead trace a compact disk around a third companion .
Higher angular resolution observations are required to investigate the nature of this source .