STAR FORMATION AND DYNAMICS

摘要

The study of the distribution and kinematics of molecular gas is essential to have an insight into the dynamical mechanisms regulating star formation in galaxy disks. We discuss some of the latest results issued from the mapping of CO lines in galaxies by present mm-interferometers with a special emphasis on galactic nuclei. Understanding how nuclear activity is set off and how activity is connected to the starburst phenomenon in galactic nuclei requires high resolution and high sensitivity observations of molecular gas. The physical and chemical status of molecular gas in starbursts and AGNs clearly depart from that of quiescent star forming disks. The use of specific tracers adapted to probe the onset of large-scale shocks, as well as the prevalence of photon dominated and/or X-ray chemistries in molecular gas, helps to study the feedback of starbursts on the neutral ISM. ALMA will provide a unprecedented view of the dynamics of molecular gas in galaxies by expanding the number of objects studied at high spatial resolution using CO lines. ALMA, together with HERSCHEL, will expand by orders of magnitude the number of galaxies where the study of molecular gas chemistry can be undertaken through multi-lines/multi-species observations.