RHESSI Observation of Chromospheric Evaporation

Details RHESSI Observation of Chromospheric Evaporation RHESSI Observation of Chromospheric Evaporation

2006-03-19

arxiv.org/abs/astro-ph/0603510v2

Astrophys.J.649:1124-1139,2006

Astronomy and Astrophysics

Astrophysics

36 pages, 14 figures (ApJ Vol. 649, No. 1, Sept 20, 2006, in press)

Scientific paper

10.1086/506268

We present analyses of the spatial and spectral evolution of hard X-ray emission observed by {\it RHESSI} during the impulsive phase of an M1.7 flare on 2003 November 13. In general, as expected, the loop top (LT) source dominates at low energies while the footpoint (FP) sources dominate the high energy emission. At intermediate energies, both the LT and FPs may be seen, but during certain intervals emission from the legs of the loop dominates, in contrast to the commonly observed LT and FP emission. The hard X-ray emission tends to rise above the FPs and eventually merge into a single LT source. This evolution starts first at low energies and proceeds to higher energies. The spectrum of the resultant LT source becomes more and more dominated by a thermal component with an increasing emission measure as the flare proceeds. The soft and hard X-rays show a Neupert-type behavior. With a non-thermal bremsstrahlung model the brightness profile along the loop is used to determine the density profile and its evolution, which reveals a gradual increase of the gas density in the loop. These results are evidence for chromospheric evaporation and are consistent with the qualitative features of hydrodynamic simulations of this phenomenon. However, some observed source morphology and its evolution cannot be accounted for by previous simulations. Therefore simulations with more realistic physical conditions are required to explain the results and the particle acceleration and plasma heating processes.

Affiliated with

Also associated with

No associations

Rating

RHESSI Observation of Chromospheric Evaporation does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with RHESSI Observation of Chromospheric Evaporation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and RHESSI Observation of Chromospheric Evaporation will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-170263