EVIDENCE FOR STABLE v = 0, J = 1 → 0 SiO MASER EMISSION FROM VY CANIS MAJORIS

Abstract

Observations of the SiO v=0, J=1→0 spectra from VY CMa from 2003 through 2006 indicate an unusually long-lived, highly linearly polarized maser emission at a Vlsr of approximately 18.5 km/s. A time series cross-correlation analysis has been developed for calculating the characteristic lifetime of linearly polarized spectra. Applying the cross-correlation to these spectra indicates a characteristic lifetime of 5600 ± 400 days. These emission characteristics may be generated in a region of relatively stable outflow geometry and magnetic field rather than in the more ephemeral circumstellar environment.