Multiwavelength Study of a Solar Eruption from AR NOAA 11112: II. Large-Scale Coronal Wave and Loop Oscillation

摘要

We analyze multiwavelength observations of an M2. 9/1N flare that occurred in AR NOAA 11112 on 16 October 2010. AIA 211 ? EUV images reveal the presence of a faster coronal wave (decelerating from ≈ 1390 to ≈ 830 km s~(-1)) propagating ahead of a slower wave (decelerating from ≈ 416 to ≈ 166 km s~(-1)) towards the western limb. The dynamic radio spectrum from Sagamore Hill radio telescope shows the presence of a metric type II radio burst, which reveals the presence of a coronal shock wave (speed ≈ 800 km s~(-1)). The speed of the faster coronal wave, derived from AIA 211 ? images, is found to be comparable to the coronal shock speed. AIA 171 ? high-cadence observations showed that a coronal loop, which was located at a distance of ≈ 0. 32R_⊙ to the west of the flaring region, started to oscillate by the end of the impulsive phase of the flare. The results indicate that the faster coronal wave may be the first driver of the transversal oscillations of coronal loop. As the slower wave passed through the coronal loop, the oscillations became even stronger. There was a plasmoid eruption observed in EUV and a white-light CME was recorded, having velocity of ≈ 340 - 350 km s~(-1). STEREO 195 ? images show an EIT wave, propagating in the same direction as the lower-speed coronal wave observed in AIA, but decelerating from ≈ 320 to ≈ 254 km s~(-1). These observations reveal the co-existence of both waves (i. e. coronal Moreton and EIT waves), and the type II radio burst seems to be associated with the coronal Moreton wave.