We present new multi-wavelength millimeter interferometric observations of the Herbig Ae star HDÂ 163296 obtained with the IRAM/PBI , SMA and VLA arrays both in continuum and in the ^ { 12 } CO , ^ { 13 } CO and C ^ { 18 } O emission lines .
Gas and dust properties have been obtained comparing the observations with self-consistent disk models for the dust and CO emission .
The circumstellar disk is resolved both in the continuum and in CO. We find strong evidence that the circumstellar material is in Keplerian rotation around a central star of 2.6Â M _ { \odot } .
The disk inclination with respect to the line of sight is 46 ^ { o } \pm 4 ^ { o } Â with a position angle of 128 ^ { o } \pm 4 ^ { o } .
The slope of the dust opacity measured between 0.87 and 7Â mm ( \beta = 1 ) confirms the presence of mm/cm-size grains in the disk midplane .
The dust continuum emission is asymmetric and confined inside a radius of 200Â AU while the CO emission extends up to 540Â AU .
The comparison between dust and CO temperature indicates that CO is present only in the disk interior .
Finally , we obtain an increasing depletion of CO isotopomers from ^ { 12 } CO to ^ { 13 } CO and C ^ { 18 } O .
We argue that these results support the idea that the disk of HDÂ 163296 is strongly evolved .
In particular , we suggest that there is a strong depletion of dust relative to gas outside 200Â AU ; this may be due to the inward migration of large bodies that form in the outer disk or to clearing of a large gap in the dust distribution by a low mass companion .