"The 3D barrier in star formation"

Juergen Steinacker (LERMA & MPIA/Heidelberg)

Although stars are the most prominent objects in astronomy, we still do not understand how they form.
Many observations and simulations indicate that star formation is a complex interplay of gravitation, gas
forces, magnetic fields, radiation, chemistry, and turbulence. But it remains to be determined which agents
initiate and dominate the formation process at what time. Currently, this research about the physical
mechanisms triggering the initial collapse of molecular cloud cores hits a barrier. For well-resolved nearby
cores, both the quality of observational data as well as the simulation resolutions are ready for 3D modeling,
but the models are not. And this gap will widen with new data from Herschel and ALMA.
I this talk, I will review the obstacles that hinder the development of 3D models for early star formation. In a
selection of examples I will report on currently performed research to overcome them. The applications range
from the 3D structure of molecular cloud cores, the dust properties and their growth in cores, to candidates for
circumstellar disks around young massive stars. The modeled data cover the wavelength range from optical
over MIR to mm observations."