Water in Star and Planet Forming Regions

Abstract: In this paper we discuss the astronomical search for water vapor in order to understand the disposition of water in all its phases throughout the process of star and planet formation. Our ability to detect and study water vapor has recently received a tremendous boost with the successful launch and operations of the Herschel Space Observatory. Herschel spectroscopic detections of numerous transitions in a variety of astronomical objects, along with previous work by other space-based observatories, will be threaded throughout this contribution. In particular, we present observations of water tracing the earliest stage of star birth where it is predominantly frozen as ice. When a star is born the local energy release by radiation liberates ices in its surrounding envelope and powers energetic outflows that appear to be water factories. In these regions water plays an important role in the gas physics. Finally, we end with an exploration of water in planet forming disks surrounding young stars. The availability of accurate molecular data (frequencies, collisional rate coefficients, and chemical reaction rates) are crucial to analyze the observations at each of these steps.