Princeton University Star Formation/ISM Rendezvous (SFIR)

Local star formation thresholds proposed in the literature typically refer to a gas density above which star formation occurs. There has been plenty of debate regarding the existence of such a threshold. I will discuss how we can search for a threshold in simulations, recover it from observations, and link this star formation threshold to the gas density PDF in molecular clouds. Using simulations of supersonic, isothermal, self-gravitating turbulence, we can systematically study the variation of the density PDF with global cloud properties like the Mach number or Virial parameter, and come up with analytical relations that describe this dependence I will highlight how the different moving parts of the density PDF can be determined in terms of these global cloud parameters.