Computing time at IT4I

We were again successful in the competition for time on national supercomputer IT4Innovations. PhD student Camille Landri won 20 000 node hours (4.32 million CPU hours) on Barbora cluster and postdoc Damien Gagnier secured 82 000 node hours (10.496 million CPU hours) on Karolina cluster. Both awards are intended for projects involving binary star interactions and common envelope evolution.

Post-dynamical inspiral phase of common envelope evolution. The role of magnetic fields

In his newest paper, Damien Gagnier takes the next step by simulating post-dynamical common envelope evolution with MHD with Athena++. We see amplification of B to similar levels as in other contemporary work, but with a much lower kinetic-to-magnetic energy ratio and no evidence for jets. Magnetic fields have a negligible impact on many features including binary orbit evolution. Damien performed detailed analysis of reservoirs of energy and transfer between them. He also measured α-disk parameter of ≃0.034, but the “viscosity” is not straighforwardly due to B. There is much more – check out the paper at, now under review in A&A.

EAS meeting 2023

Our group had a strong presence at the EAS meeting in Krakow, where Jakub Cehula, Damien Gagnier, Milan Pešta, and Ondřej Pejcha presented talks. It was great meeting old friends, making new, and learning about exciting science.