Skip to main content


Wednesday 10 Feb 2021Molecular clouds: linking simulations and observations

Daniel Seifried -

Remote seminar 14:00-15:00

In my talk I will present simulations of molecular cloud formation in galactic disks within the SILCC-Zoom collaboration. The simulations include a detailed chemical network for H_2 and CO formation and thus provide a unique tool to discuss important aspects of molecular cloud formation: the (1) chemo-dynamical evolution and (2) the comparison with actual observations by means of synthetic observations. I will show that molecular clouds can be out of chemical equilibrium which provides a huge challenge for numerical simulations. I will also discuss how the complex filamentary structure of these molecular clouds can affect their interaction with stellar feedback like supernova but also the emission of e.g. the CO(1-0) and the HI 21 cm line. Furthermore, in view of the increasing number of polarisation observations, I present the first self-consistent synthetic dust polarisation maps created with the POLARIS code. I will show that observed polarisation vectors in clouds probe the real field structure with an accuracy of about 5 degree and that the long-debated de-polarisation on clouds scales results from strongly tangled field lines rather than inefficient grain alignment. Finally, I will shed light on the origin of the alignment of magnetic fields and density structures as recently observed by e.g. the Planck and BlastPol collaboration.

Add to calendar

Add to calendar (.ics)