EDP Sciences
Free access
Issue
A&A
Volume 417, Number 1, April I 2004
Page(s) 325 - 332
Section The Sun
DOI http://dx.doi.org/10.1051/0004-6361:20034249


A&A 417, 325-332 (2004)
DOI: 10.1051/0004-6361:20034249

Series of high-frequency slowly drifting structures mapping the flare magnetic field reconnection

M. Karlický

Astronomical Institute of the Academy of Sciences of the Czech Republic, 25165 Ondrejov, Czech Republic
(Received 30 August 2003 / Accepted 28 November 2003)

Abstract
Rare series of the slowly drifting structures observed during two solar flares (April 11, 2001 and March 18, 2003) in the 0.8-4.5 GHz frequency range are studied. Their time-frequency evolution is compared with topological and X-ray characteristics of the flares. Based on recent modelling of the magnetic field reconnection in the bursting and intermittent regime, it is proposed that these slowly drifting structures map the flare magnetic field reconnection. In such a scenario the drifting structures correspond to the radio emission from primary and secondary plasmoids which are formed in the extended current sheet due to tearing and coalescence processes and they move upwards in the solar atmosphere. An increase and decrease of the frequency drifts of the drifting structures in the initial and decaying flare phases are interpreted as an increase and decrease of the reconnection rate, respectively. On the other hand, individual bursts in the drifting pulsating structures are considered to be radio manifestations of separate electron beams accelerated during the secondary tearing processes. The observed characteristic times are compared with those theoretically predicted and the basic plasma parameters in the flare process are estimated.


Key words: plasmas -- Sun: flares -- Sun: radio radiation -- Sun: activity




© ESO 2004

What is OpenURL?

The OpenURL standard is a protocol for transmission of metadata describing the resource that you wish to access.

An OpenURL link contains article metadata and directs it to the OpenURL server of your choice. The OpenURL server can provide access to the resource and also offer complementary services (specific search engine, export of references...). The OpenURL link can be generated by different means.

  • If your librarian has set up your subscription with an OpenURL resolver, OpenURL links appear automatically on the abstract pages.
  • You can define your own OpenURL resolver with your EDPS Account.
    In this case your choice will be given priority over that of your library.
  • You can use an add-on for your browser (Firefox or I.E.) to display OpenURL links on a page (see http://www.openly.com/openurlref/). You should disable this module if you wish to use the OpenURL server that you or your library have defined.