Interaction between AGB Wind and Nova Outburst: The Case of V407 Cyg, a Symbiotic Star

We report on the time variation of SiO maser emission from the symbiotic star V407 Cyg after the classical nova outburst with concurrent γ-ray emission in 2010 March. The SiO J=1–0, v=2 line at 42.821 GHz has been detectable persistently, but the line profile exhibited a dramatic change two weeks after the outburst. A new persistent component appeared at the lower velocity side in the spectrum three weeks later. The observation indicates that the SiO emitting regions were terminated in a time-scale of two weeks by the hot wind of the nova, but the region was replenished quickly by cool molecular gases expelled from the mira, possibly through the first Lagrangian point of the binary system