Water Vapor Reservoirs In Herbig AeBe disks
Water is a fundamental molecule for the physical and chemical evolution of proto-stellar and proto-planetary systems and eventually for the fomation of planetary atmospheres. Spitzer observations have revealed a high abundance of water in the inner region of protoplanetary disks. Most recent observations with Herschel shed light on the water content in the outer, cold, disk reservoir. The relative flux of multiple water transitions can be directly used to address the different reservoirs of water in disks. In my talk I will present new results on the water vapor abundance in two Herbig Ae disks, namely HD 100546 and HD 163296. The analysis of the Herschel (PACS and HIFI) spectra shows that, despite the similar stellar mass, the distribution of water vapor in the two disks is very different.