These clouds contain a surprisingly rich variety of molecules and small solid particles called grains, and form a unique chemical laboratory in which processes occur that are not normally found in a laboratory on Earth. Moreover, dark clouds are the birthplaces of new stars and planets, and molecular lines are often the only means to penetrate and study these stellar nurseries. The gas and dust in clouds provide the raw building blocks from which future planetary systems are made, so that tracing their chemical evolution is an essential step in establishing our origins. These questions are addressed through observations at submillimeter and infrared wavelengths, combined with models of the excitation and abundance of molecules. Our group uses primarily data obtained with ISO , JCMT , CSO , OVRO millimeter array and ESO-VLT .
Molecular lines are excellent diagnostics of the physical conditions in star-forming regions.
From the relative strength of lines information about temperature and density can be obtained, whereas the absolute strengths give the abundances. The line profiles provide kinematical and dynamical data. To extract this information, sophisticated radiative transfer models are required, some of which have been developed in our group. Our research focusses on a systematic study of the physical and chemical structure of young stellar objects at different stages of evolution, including low-mass protostars, massive stars in the embedded phase, and circumstellar disks around young stars. In the Sackler Laboratory for Astrophysics, the physical and chemical processes that take place in these ices are simulated.