Radio-quiet fast and wide coronal mass ejections

We report on the properties of radio-quiet (RQ) and radio-loud (RL) coronal mass ejections (CMEs) that are fast and wide (FW). RQ CMEs lack type II radio bursts in the metric and decameter-hectometric (DH) wavelengths. RL CMEs are associated with metric or DH type II bursts. We found that similar to 40% of the FW CMEs from 1996 to 2005 were RQ. The RQ CMEs had an average speed of 1117 km s(-1) compared to 1438 km s(-1) for the RL, bracketing the average speed of all FW CMEs (1303 km s(-1)). The fraction of full halo CMEs (apparent width 360 degrees) was the largest for the RL CMEs (60%), smallest for the RQ CMEs (16%), and intermediate for all FW CMEs (42%). The median soft X-ray flare size for the RQ CMEs (C6.9) was also smaller than that for the RL CMEs (M3.9). About 55% of RQ CMEs were back sided, while the front-sided ones originated close to the limb. The RL CMEs originated generally on the disk with only similar to 25% being back sided. The RQ FW CMEs suggest that the Alfven speed in the low-latitude outer corona can often exceed 1000 km s(-1) and can vary over a factor of >= 3. None of the RQ CMEs was associated with large solar energetic particle events, which is useful information for space weather applications.