SPRG Seminars
April 9, 2013:
"Radio Observations of Coronal Mass Ejections"
Hazel Bain, Space Sciences Laboratory, University of California at Berkeley
Traditionally, studies of the initiation and propagation phases of coronal mass ejections (CMEs) are carried out using extreme ultraviolet (EUV) and white light observations. However, meter wavelength radio observations have also proven to be ideal for investigating sources of coherent and incoherent emission during the early propagation phases of the CME. For example, observations from the Nançay Radioheliograph (NRH) have shown gyrosynchrotron emission, from nonthermal accelerated electrons, present in the expanding loops of CMEs. Furthermore CMEs are often associated with a variety of radio bursts observed at metric and decametric wavelengths. In particular type II radio bursts, which are considered to be a proxy for a shock associated with the propagating CME.
Using radio imaging and spectroscopy we can characterize the electron distribution and plasma parameters present in these sources. In this talk I will present the results of several such studies which used radio observations from NRH in conjunction with EUV observations from the Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamics Observatory, to investigate sources energetic electrons in the CME system, from the corona to the interplanetary medium.