Chunliang Mu

Light curves of 3D Common Envelope Simulations

The common envelope (CE) binary interaction happens when two stars’ come so close that their envelopes merge. This typically takes place when one of the two stars expands on its journey to becoming a giant. Typically the more compact of the two stars experience a (gravitational) drag force at the hand of the envelope of the larger star, which leads to either the complete ejection of the common envelope, or to the companion merging with the primary. CEs are thought to be the main mechanism to form compact evolved binaries such as the neutron star binaries, NS-black-hole or binary black holes that can merge and generate observable gravitational waves. It is entirely plausible that the transients named luminous red novae are common envelope interactions caught in the act. 3D simulations are required to quantify the CE physical mechanism, due to the complex asymmetric nature of CE evolution. To constrain the simulations and make them effective tools to explain observations, we need to predict light curves. Here I present the first light curve results of our SPH-based 3D numerical CE simulations, including an assessment of the uncertainty and future steps.