Is molecular gas necessary for star formation? Simon Glover Institute for Theoretical Astrophysics, Heidelberg, Germany
The fact that star formation appears to take place only within molecular clouds can be easily explained if one assumes that the cooling provided by molecular gas is a necessary prerequisite to the onset of star formation. However, there is growing evidence that this explanation is incorrect, and that the efficient formation of molecular gas is simply a consequence of the same dynamical processes that also lead to the formation of stars. In this contribution, I will discuss a number of recent numerical simulations of cloud formation and evolution that follow the detailed chemistry and thermodynamics of the gas and that provide strong support for this picture. I will also discuss the consequences of this picture for our understanding of star formation in extreme environments.
Collaborators: P. Clark, ITA, Germany R. Klessen, ITA, Germany	Key publication