Community of European Solar Radio Astronomers – Page 24

Topical issue on solar radio physics published
by Ludwig Klein, Silja Pohjolainen and Lidia van Driel Gesztelyi

2008-11-25 119 views

Topical issue on solar radio physics published CESRA 2007 Workshop The CESRA workshop in 2007, titled Solar Radio Physics and the Flare-CME Relationship, was held at the University of Ioannina in Greece. Some 70+ participants attended the meeting, which consisted of invited and contributed talks in the mornings and working group discussions and presentations in the afternoons. The topics for the four working groups were 1) pre-flare and pre-CME phase, […]

Fragmented radio emission reveals a shock passing through solar active region loops
by Silja Pohjolainen, Jens Pomoell and Rami Vainio

2008-09-02 1,031 views

Shocks and type II bursts Radio type II bursts are observed in association with flares and coronal mass ejections (CMEs). Metric type II bursts can be observed in dynamic radio spectra as slowly drifting emission lanes, with drift rates approximately 0.1 — 1.0 MHz/s. The start frequency of metric type II bursts is usually at about 100 — 200 MHz. The mechanism behind the bursts is generally assumed to be […]

Type III bursts, magnetic field extrapolations, and the propagation of solar energetic particles
by Karl-Ludwig Klein

2008-08-21 408 views

Energetic particle propagation from the Sun to Earth Enhanced fluxes of solar energetic particles (SEP) — so-called SEP events — result from processes of explosive energy conversion in the corona, notably flares and coronal mass ejections. From Parker’s model of the interplanetary magnetic field, it is expected that particles accelerated in the corona reach the Earth, provided they are injected into interplanetary magnetic flux tubes near 50°—60° western longitude. Statistically […]

Synchrotron Radio Emission from a Fast Halo Coronal Mass Ejection
by Tim Bastian

2007-12-27 374 views

Coronal and interplanetary (IP) type II radio emissions are widely believed to result from the interaction of a super-Alfvenic shock with the coronal and/or the interplanetary medium, producing plasma radiation at the fundamental and/or harmonic of the electron plasma frequency. In the case of coronal type II radio bursts, the nature of the shock driver remains controversial: flare blast waves, flare ejecta, and coronal mass ejections (CMEs) have all been […]

A New Wind/WAVES Type II Burst Catalog Available Online
by Nat Gopalswamy

2007-11-22 308 views

The CDAW Data Center announces the availability of a new catalog of type II radio bursts detected by the Radio and Plasma Waves (WAVES) experiment on board the Wind spacecraft and the associated coronal mass ejections (CMEs) observed by the Solar and Heliospheric Observatory (SOHO). The catalog is available at http://cdaw.gsfc.nasa.gov/CME_list/radio/waves_type2.html The catalog also contains information on the associated flares (X-ray importance and NOAA active region number). The CME sources […]

Radio monitoring of solar activity
by Monique Pick

2007-04-24 98 views

We are pleased to announce the opening of a new web site Radio monitoring at http://secchirh.obspm.fr This radio survey is a joint effort of the Paris Observatory, the University of Athens, the University of Ioannina, and the Solar Physics Branch of the Naval Research Laboratory. The site is still under construction. At the present stage, it provides a daily survey (08-16 UT) which includes: Radio spectra covering the 600 MHz-30 […]

A solar type N burst at decametric wavelengths
by Karl-Ludwig Klein

2007-03-12 286 views

Electron beams travelling through the solar corona excite Langmuir waves near the local electron plasma frequency. When these Langmuir waves are converted into electromagnetic waves, the radiation can be detected by radio telescopes as bursts with very specific spectral signatures that depend on the magnetic structure which guides the beams. E.g., an electron beam that propagates upward along open magnetic fields produces a short pulse of emission at systematically decreasing […]

Radio-quiet Fast and Wide Coronal Mass Ejections
by Nat Gopalswamy

2007-02-07 81 views

Radio-quiet coronal mass ejections (CMEs) are those with no detectable type II radio emission in the metric and decameter-hectometric (DH) wavelengths. (The CMEs may be associated with other types of radio emission such as type III bursts, see definitions for the different types of bursts or the diagram of burst classification). The radio-loud CMEs are those with identifiable type II burst in the DH domain from Wind/WAVES data, irrespective of […]

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