VLT-ISAAC 3-5 μm Spectroscopy of Low-Mass Young Stellar Objects: Prospects for CRIRES.

We present results from an extensive spectroscopic survey in the 3-5 μm wavelength region of low-mass young stellar objects using VLT-ISAAC. Medium resolution spectra (λ/$\varDelta\lambda$ ~ 1000-10000) of young embedded stars in the mid-infrared allow for detailed studies of ro-vibrational lines from molecular gas, interstellar ices and Polycyclic Aromatic Hydrocarbons (PAHs). By taking advantage of this wide range of molecular tracers available within a few spectral settings, the survey has helped to constrain the chemical evolution of cold molecular material in low-mass star forming regions as well as the physics of disks surrounding protostars. In this contribution, we will review the various spectral diagnostics of molecular material, which require ground-based high resolution infrared spectroscopy. The importance of a high resolution spectroscopic capability as will be offered by CRIRES is discussed in the context of the physics and chemistry of low-mass star formation. [ABSTRACT FROM AUTHOR]