Characteristics of coronal mass ejection associated with DH type II radio bursts (All and Limb events)

Abstract

We have studied the characteristics of coronal mass ejections (CMEs) associated with Deca-Hectometric (DH) type II radio bursts (1–14 MHz) in the interplanetary medium during the year 1997–2005. The DH CMEs are divided into two parts: (i) DH CMEs (All) and (ii) DH CMEs (Limb). We found that 65% (177/273) of all events have the speed >900 km s−1 and the remaining 35% (96/273) events have the speed below 900 km s−1. The average speed of all and limb DH CMEs are 1230 and 1288 km s−1, respectively, which is nearly three times the average speed of general population of CMEs (473 km s−1). The average widths of all and limb DH CMEs are 105° and 106°, respectively, which is twice the average width (52°) of the general population of CMEs. We found a better correlation between the speed and width of limb DH CMEs (R=−0.61) than all DH CMEs (R=−0.53). Only 28% (177/637) of fast >900 km s−1 general population of CMEs are reported with DH type II bursts counterpart. The above results gives that the relation between the CME properties is better for limb events.