Mid-IR Water Emission and the 10 μm Silicate Feature in Protoplanetary Disks Surrounding T Tauri Stars

To get en enhanced understanding of water in the planet forming region of protoplanetary disks, it is important to understand how dust, which is the main source of opacity affects the mid-IR emission of water. Therefore, this thesis presents a comprehensive study of the connection between the mid-IR water emission and the peak strength of the 10 μm silicate feature. Besides the investigation of observational data of TTauri disk systems that involved the analysis of Spitzer spetra, a detailed view on the influence of the structure of protoplanetary disks on these quantities is provided using the protoplanetary disk model (ProDiMo) from Woitke et al. (2009). Effects of grain growth, total disk gas mass and central star were explored. No correlation is found from the observations, but rather a diverse behavior between these quantities. Analysis of the silicate feature shows that sources with lower peak strengths of the silicate feature show larger degrees of crystallization. From the model series we find an anti-correlation between the mid-IR water emission and the peak strength of the 10 μm silicate feature, and showed that the peak strength of the 10 μm silicate feature is proportional to the bolometric luminosity. Our results show that dust significantly alters the emission of water, and thus reflects the fact that the amount of water emission that is observed from protoplanetary disks in not per se reflecting the abundance of water.