Formation of dense gas cores in supernova remnant-cloud interactions

• Applicant: Dr. Udo Ziegler
• Subject Area: Astrophysics and Astronomy
• Term: from 2014 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 262821815

Star formation takes place in dense, gravity-bound gas aggregations within interstellar clouds. Such pre-stellar 'cores' are believed to be created by the nonlinear interaction between gravity and strongly converging flows emerging in a turbulent environment sustained by energy input from e.g. supernova explosions. In this project, the idealized but fundamental problem is studied whether the collision of an isolated supernova remnant with an interstellar cloud is able to trigger in-situ core formation. In order to achieve this goal, high-level numerical modeling based on state-of-the-art numerics, adaptive mesh refinement and parallel computing is conducted using the NIRVANA simulation software. Our model couples magnetohydrodynamics with self-gravity, radiative cooling of the interstellar medium and anisotropic thermal conduction. Although lacking other physics like non-ideal magnetohydrodynamical processes and detailed ionisation/chemistry, the approach means a substantial improvement over current shock-cloud interaction models. Major progress in this respect stems from the development of a parallel Poisson solver and from the implementation of an efficient stiff integrator for the anisotropic thermal conduction term. The stiff integrator for conduction makes a modeling of the supernova remnant expansion computationally accessible and, hence, allows to go beyond the usually adopted small-cloud approximation.By exploring the complex interplay between all aforesaid physical effects in three-dimensional simulations the project aims to contribute to the key question under which conditions dense gas cores may be formed before the crushed cloud is disrupted by the action of magnetohydrodynamical instabilities.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1573: Physics of the Interstellar Medium