O2 signature in thin and thick O2-H2O ices

We present a systematic set of experiments with O_2_-H_2_O ice mixtures designed to disentangle how the molecular ratio affects the O_2_ signature in the mid- and near-infrared spectral regions. All the experiments were conducted in a closed-cycle helium cryostat coupled to a Fourier transform infrared spectrometer.

The ice mixtures comprise varying thicknesses from 8x10^-3^ to 3um. The absorption spectra of the O_2_-H_2_O mixtures are also compared to the one of pure water. In addition, the possibility to detect the O_2_ in icy bodies and in the interstellar medium is discussed.