A multiwavelength study of three solar flares
| dc.contributor.author | Kundu, M. R. | en |
| dc.contributor.author | Nindos, A. | en |
| dc.contributor.author | White, S. M. | en |
| dc.contributor.author | Grechnev, V. V. | en |
| dc.date.accessioned | 2015-11-24T18:33:41Z | |
| dc.date.available | 2015-11-24T18:33:41Z | |
| dc.identifier.issn | 0004-637X | - |
| dc.identifier.uri | https://olympias.lib.uoi.gr/jspui/handle/123456789/16780 | |
| dc.rights | Default Licence | - |
| dc.subject | sun : corona | en |
| dc.subject | sun : flares | en |
| dc.subject | sun : radio radiation | en |
| dc.subject | sun : x-rays, gamma rays | en |
| dc.subject | x-ray observations | en |
| dc.subject | microwave-bursts | en |
| dc.subject | flaring loop | en |
| dc.subject | millimeter emission | en |
| dc.subject | radio-emission | en |
| dc.subject | acceleration | en |
| dc.subject | wavelengths | en |
| dc.subject | configuration | en |
| dc.subject | resolution | en |
| dc.subject | images | en |
| dc.title | A multiwavelength study of three solar flares | en |
| heal.abstract | In this paper we seek a self-consistent model for three strong limb flares observed at 17 and 34 GHz by the Nobeyama radioheliograph and also in soft X-rays and hard X-rays by the Yohkoh SXT (Soft X-Ray Telescope) and HXT (Hard X-Ray Telescope) instruments. Additional radio spectral data were provided by the Nobeyama polarimeter. The flare geometry is simple, with one well-defined flaring loop in each event. The 17 and 34 GHz emissions are optically thin gyrosynchrotron radiation from energetic electrons that outlines the flaring loops and peaks close to the loop tops. We infer that the variation of magnetic field along the loops is vary small. We try to reproduce the observed radio morphologies and fluxes using a model gyrosynchrotron loop. The results of our modeling rely on the model magnetic field geometry that we choose. Although the exact loop geometry cannot be constrained from a two-dimensional snapshot, we choose for simplicity a line-dipole magnetic field, and the model field lines are circular. The. SXT/HXT images are used to provide the physical parameters of the model loops. The high-frequency polarimeter data give the energy spectral index of the radio-emitting electrons. We could not reconcile the observed radio morphologies and fluxes using classic dipole magnetic field models. The best-fit model that uses the same input parameters for both frequencies and partly reconciles the observed 17 and 34 GHz morphologies and fluxes is produced when we invoke a magnetic field with constant strength along the model loop. These model loops have uniform thickness. The derived densities of the radio-emitting electrons are (1-6) x 10(4) cm(-3) with energy limits between 60 and 5000 keV. These models are the best fits we can get under the best assumptions we can justify, but they do not in fact match the radio morphologies very well; their problems and limitations are discussed. | en |
| heal.access | campus | - |
| heal.fullTextAvailability | TRUE | - |
| heal.identifier.secondary | <Go to ISI>://000170704800036 | - |
| heal.identifier.secondary | http://iopscience.iop.org/0004-637X/557/2/880/pdf/0004-637X_557_2_880.pdf | - |
| heal.journalName | Astrophysical Journal | en |
| heal.journalType | peer reviewed | - |
| heal.language | en | - |
| heal.publicationDate | 2001 | - |
| heal.recordProvider | Πανεπιστήμιο Ιωαννίνων. Σχολή Επιστημών και Τεχνολογιών. Τμήμα Βιολογικών Εφαρμογών και Τεχνολογιών | el |
| heal.type | journalArticle | - |
| heal.type.el | Άρθρο Περιοδικού | el |
| heal.type.en | Journal article | en |