A hydrodynamic model of the gradual phase of the solar flare loop

Journal Article · Sun Jul 01 04:00:00 EDT 1990 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/168989· OSTI ID:6577286

Gan, W Q; Fang, C ^[1]

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1. Purple Mountain Observatory, Nanjing (China) China Center for Advanced Science and Technology, Beijing (China) Nanjing Univ. (China)

The hydrodynamic cooling process after the maximum phase of a solar flare has been simulated numerically, with improvements on the chromospheric radiative loss and the resolution of the transition region, together with the introduction of the mechanism of chromospheric heating by coronal soft X-rays. At the early stage of the gradual phase, chromospheric evaporation continues to take place and the transition region moves further downward. At the middle stage of the gradual phase, the corona atmosphere appears to have a quasi-periodic oscillation, and the transition region remains at the same position for a long time. At the later stage to of the gradual phase, the descent of coronal material does not happen, and the atmosphere evolves into a state with high density and low temperature. Finally, the atmosphere does not reach the quiet-sun conditions directly, and it would perhaps undergo a process of instability and develop into the stage of postflare loop. The efficiency of flare soft X-ray heating of the chromosphere is also discussed. 43 refs.

• OSTI ID: 6577286
• Journal Information: Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 358; ISSN ASJOA; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

640104* -- Astrophysics & Cosmology-- Solar Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERES
CHROMOSPHERE
COOLING
ELECTROMAGNETIC RADIATION
EVAPORATION
FLUID MECHANICS
HEATING
HYDRODYNAMICS
IONIZING RADIATIONS
MATHEMATICAL MODELS
MATHEMATICS
MECHANICS
NUMERICAL ANALYSIS
PHASE TRANSFORMATIONS
RADIATIONS
SOLAR ACTIVITY
SOLAR ATMOSPHERE
SOLAR FLARES
STAR MODELS
X RADIATION