Development of flare morphology in X-rays, and the flare scenario

✍ Scribed by C. Jager

• Publisher: Springer
• Year: 1983
• Tongue: English
• Weight: 580 KB
• Volume: 86
• Category: Article
• ISSN: 0038-0938
• DOI: 10.1007/bf00157171

✦ Synopsis

We define the ~p~iUs phgL6s of a flare as its first phase, characterized by: X-ray bursts of short (seconds to tens of seconds) duration, a patchy X-ray morphology, and injection of energy. It lasts some five to ten minutes. The g~d~cg~ or ~s phase starts virtually at the same time as the impulsive one and is characterized by a gradually varying X-ray flux from a larger, diffuse, area situated higher than the sources of the impulsive X-ray bursts. The diffuse cloud is initially (during the first five minutes) hotter by a few million degrees than the sources of the impulsive phase bursts and is assumed to be caused by convective motions with upward velocities of a few hundred km s -I. It contains about the same number of energetic electrons as the impulsive burst patches contained initially. It cools gradually down by radiative and conductive losses, a process that may last for about an hour.