Contributed Talk - Splinter Computation

Friday, 25 September 2020, 09:28   (virtual room B)

The dispersal of molecular clouds by stellar feedback

Stefanie Walch^1, Richard W√ľnsch^2, Sebastian Haid^1, Daniel Seifried^1
1: University of Cologne; 2: Astronomical Institute, Czech Academy of Sciences, Prague

Star formation takes place in the densest and coldest parts of the interstellar medium (ISM), in dark molecular clouds. These are swept up by multiple supernova explosions on scales of several hundred parsec. While condensing out of the warm ISM, the clouds are continuously fed with fresh gas. Thus, the turbulent substructure and magnetic field properties are imprinted during cloud formation. The formation of dense clouds from the multi-phase ISM, the onset of star formation, and the evolution of the molecular clouds under the impact of stellar feedback from newly born massive stars is studied in high-resolution simulations within the SILCC-Zoom project. I will present some of our latest results on molecular cloud dispersal. For instance, we find that the detailed cloud substructure determines the clouds' vulnerability to stellar feedback processes, in particular to ionizing radiation. I will particularly focus on describing the numerical methods we use. The simulations are carried out with the modular finite-volume, adaptive mesh refinement code FLASH. We developed multiple additional physics modules, such as the radiative transfer scheme TreeRay. TreeRay is a backward radiative transfer method which uses the same Barnes-Hut tree as the self-gravity calculation. The way TreeRay is constructed, the method shows almost ideal weak and strong scaling and the computational cost is independent of the number of sources. Thus, the method is particularly powerful when ray-tracing the radiation of several tens to hundreds of massive stars, or even thousands of grid cells of radiatively cooling gas.