Detection of a Violent Line Profile Variation of the ^28SIO V=2, J=3-2 Maser Emission toward Orion KL IRC2
Time monitoring observations of the ^28SiO v=0-2, J=3-2 transitions were performed on an annual basis from 1995 to 1998 with the 14 m radio telescope at Taeduk Radio Astronomy Observatory toward Orion KL IRc2 containing the ^28SiO v=1, J=2-1 maser emission. On 1996 March 1, a violent line profile variation with three spikes was detected in the high-velocity component of the SiO v=2, J=3-2 maser. The strongest spike, with V_LSR=20.5 km s^-1, constituted a new appearance. We suggest that the line profile variation of the SiO v=2, J=3-2 maser is probably the result of time variations in bipolar outflows from a young stellar object in the Orion KL IRc2 region. In addition, our observational results show that the high-velocity component of the SiO v=2, J=3-2 maser is the most active.