Characterization of intensity and spatial variations along coronal loops II. A TRACE case study

BORGAZZI, ANDREA, COSTA, ANDREA

ASTRONOMY AND ASTROPHYSICS

EDP Science

Año: 2005 vol. 441 p. 327 - 335

0004-6361

Abstract. We describe dynamical features and evolutionary characteristics of brightening coronal loops. We describe intensity variations, both in space and time, along a coarse grain loop structure, conrming high speed velocity scenarios. We apply the method to TRACE space.born images that show a compound of several magnetic threads. MICA ground.based images display a unique non.resolved loop structure. We confirm that a coherent behavior of the intensity along neighboring magnetic tubes occurs, i.e we obtain a similar pattern from both telescopes: each has two branches, suggesting the sliding down of plasma in both directions from a given position on the loop structure. The apparent sliding down occurs in approximately 12 minutes. After the first appearance, TRACE registers two reiterations of the phenomenon suggesting a wave-based explanation. The feasibility of wave.based and fow.based models is analyzed. In either case, in order to explain the coherent coronal behavior the scenario of apparently non-interacting coronal threads requires theoretical explanations that consider uniform chromospheric conditions covering the footpoints of all the related magnetic tubes. We suggest a characteristic longitude of coherence.We describe dynamical features and evolutionary characteristics of brightening coronal loops. We describe intensity variations, both in space and time, along a coarse grain loop structure, conrming high speed velocity scenarios. We apply the method to TRACE space.born images that show a compound of several magnetic threads. MICA ground.based images display a unique non.resolved loop structure. We confirm that a coherent behavior of the intensity along neighboring magnetic tubes occurs, i.e we obtain a similar pattern from both telescopes: each has two branches, suggesting the sliding down of plasma in both directions from a given position on the loop structure. The apparent sliding down occurs in approximately 12 minutes. After the first appearance, TRACE registers two reiterations of the phenomenon suggesting a wave-based explanation. The feasibility of wave.based and fow.based models is analyzed. In either case, in order to explain the coherent coronal behavior the scenario of apparently non-interacting coronal threads requires theoretical explanations that consider uniform chromospheric conditions covering the footpoints of all the related magnetic tubes. We suggest a characteristic longitude of coherence. Key words. Solar Corona . post fare loopsSolar Corona . post fare loops