14 research outputs found
Radio Observations of the January 20, 2005 X-Class Event
We present a multi-frequency and multi-instrument study of the 20 January
2005 event. We focus mainly on the complex radio signatures and their
association with the active phenomena taking place: flares, CMEs, particle
acceleration and magnetic restructuring. As a variety of energetic particle
accelerators and sources of radio bursts are present, in the flare-ejecta
combination, we investigate their relative importance in the progress of this
event. The dynamic spectra of {Artemis-IV-Wind/Waves-Hiras with 2000 MHz-20 kHz
frequency coverage, were used to track the evolution of the event from the low
corona to the interplanetary space; these were supplemented with SXR, HXR and
gamma-ray recordings. The observations were compared with the expected radio
signatures and energetic-particle populations envisaged by the {Standard
Flare--CME model and the reconnection outflow termination shock model. A proper
combination of these mechanisms seems to provide an adequate model for the
interpretation of the observational data.Comment: Accepted for publication in Solar Physic
The Origin, Early Evolution and Predictability of Solar Eruptions
Coronal mass ejections (CMEs) were discovered in the early 1970s when space-borne coronagraphs revealed that eruptions of plasma are ejected from the Sun. Today, it is known that the Sun produces eruptive flares, filament eruptions, coronal mass ejections and failed eruptions; all thought to be due to a release of energy stored in the coronal magnetic field during its drastic reconfiguration. This review discusses the observations and physical mechanisms behind this eruptive activity, with a view to making an assessment of the current capability of forecasting these events for space weather risk and impact mitigation. Whilst a wealth of observations exist, and detailed models have been developed, there still exists a need to draw these approaches together. In particular more realistic models are encouraged in order to asses the full range of complexity of the solar atmosphere and the criteria for which an eruption is formed. From the observational side, a more detailed understanding of the role of photospheric flows and reconnection is needed in order to identify the evolutionary path that ultimately means a magnetic structure will erupt
Are there Radio-quiet Solar Flares?
This submission has been withdrawn by arXiv administrators because it is a
duplicate of astro-ph/0701570