SiO Maser Spectra of V407 Cyg after the 2010 March Nova Outburst

Abstract

We report on the time variation of SiO maser emission from the symbiotic stellar system V407 Cyg after the classical nova outburst on 2010 March 10. Although both the SiO $J=1$--0 $v=1$ and 2 lines at 43.122 and 42.821 GHz were found previously in the envelope of a mira in the binary system, only weak emission of the $J=1$--0 $v=2$ line has continuously been detectable after the nova outburst. The line profile exhibited a dramatic change several weeks after the burst; the component on the higher-velocity side of the systemic velocity disappeared two weeks after the burst, and a new persistent component appeared on the lower-velocity side later. These observations indicate that the SiO emitting regions are wiped out in a time scale of two weeks by the nova shock, but a part of the masing region is quickly replenished by cool molecular gases expelled by the mira pulsation.