The excitation of molecular gas in winds and its impact for wind detections and masses

Winds that could be important for the evolution of their host galaxies are frequently seen in molecular gas lines. The importance of molecular winds has largely been attributed to their high mass content and to their direct connection with star formation. Excitation studies of CO molecules now provide a refined view of the ISM conditions in the wind vs. in the ambient ISM. I will present examples in which winds are probed by the kinematics and/or by the heating of such molecules. A clear example is that of the nearby galaxy IC5063. ALMA data of this galaxy indicate that the accelerated molecular gas is heated near jet-ISM impact points. RADEX maps provide gas excitation temperatures of order hundred degrees Kelvin. Besides highly excited, part of the accelerated gas is also optically thin. This result can translate in an easier detection of molecular winds in intermediate/high-J CO lines, and in a lower α_CO and gas mass content of molecular winds than previously thought.