A High-Frequency Type Ii Solar Radio Burst Associated With the 2011 February 13 Coronal Mass Ejection

We examine the relationship between the high-frequency (425 MHz) type II radio burst and the associated white-light coronal mass ejection (CME) that occurred on 2011 February 13. The radio burst had a drift rate of 2.5 MHz s −1 , indicating a relatively high shock speed. From SDO /AIA observations we find that a loop-like erupting front sweeps across high-density coronal loops near the start time of the burst (17:34:17 UT). The deduced distance of shock formation (0.06 Rs) from the flare center and speed of the shock (1100 km s −1 ) using the measured density from SDO /AIA observations are comparable to the height (0.05 Rs, from the solar surface) and speed (700 km s −1 ) of the CME leading edge observed by STEREO /EUVI. We conclude that the type II burst originates even in the low corona (<59 Mm or 0.08 Rs, above the solar surface) due to the fast CME shock passing through high-density loops.