Is the Asymmetric Cone Model for Halo Coronal Mass Ejections Correct?

Abstract

A set of 106 limb CMEs which are wide and could be possible halo events, when directed towards Earth, are used to check the accuracy of the asymmetric cone model. For this purpose characteristics of CMEs (widths and radial speeds) measured for the possible halo CMEs are compared with these obtained for halo CMEs using the asymmetric cone model (Michalek, Solar Phys.237, 101, 2006). It was shown that the width and speed distributions for both datasets are very similar and with a probability of p>0.93 (using the Kolmogorov – Smirnov test) were drawn from the same distribution of events. We also determined the accurate relationship between radial (Vrad) and expansion (Vexp) speeds of halo CMEs. This relation for the halo CMEs is simply Vrad=Vexp and could be very useful for space weather application.