Investigating supercooled water with laser- and X-ray spectroscopy

Water exhibits a variety of anomalies, some of which are particularly pronounced in the supercooled region. Its specific properties and possible structural and dynamical origins have been extensively studied, leading to the still inconclusive theory that water may exist in two structural motifs at low temperatures. In this talk, experimental results of temperature-dependent studies of various properties of liquid water will be presented. Special emphasis will be placed on experiments investigating liquid jets evaporatively cooled in vacuum using Raman and soft X-ray emission spectroscopy. For the specific sample environments, the methods give access to the temperature-dependent behavior of the inter- and intramolecular vibrational modes, the electronic structure, and also optical properties such as the refractive index of the liquid.