H2O in Protoplanetary Disks: the Snow Line and the Planets' Nest

Protoplanetary disks represent the stage between the pre-stellar collapse of the molecolar cloud and the formation of a planetary system surrounding a main sequence star. The goal of the DIANA FP7 project (P.I.: P.Woitke) is to investigate the disks in multiwavelengths, considering available data of photometry and spectroscopy, and give reason of the observed single and global properties of the protoplanetary disks. It will work on a sample of 85 selected targets in different evolutionary stage and surrounding different central stars. At NIR-MIR wavelengths, it is possible observe many lines of water. Water is one of the main cooling agents of the disk, due to its abundance and the presence of energy levels with excitation temperatures from few tens to few thousands of Kelvin. Water can also exist in condensate phase (frozen on dust) outside the so-called "snow line", which increases the surface density of solid material and therefore helps the formation of planets. Using a range of water lines, we can scan the disk surface, thus probing the disk from the lowest to the highest temperature regions and potentially indirectly detect the presence of the "snow line". Spectroscopic data from Spitzer and Herschel is used to investigate the spatial distribution and the synthesis of water, in the context of the thermophysical structure of the disk. This study is carried out with the codes ProDiMo and MCMax, producing different models of disks and investigating the physical conditions to which the water spectroscopy is sensitive. The work is done as part of the FP7 DIANA project.