1. TOMASZ MROZEK ASTRONOMICAL INSTITUTE, WROCŁAW UNIVERSITY
Energy-height relation for hard X-ray footpoint sources observed by RHESSI.
TOMASZ MROZEK
ASTRONOMICAL INSTITUTE, WROCŁAW UNIVERSITY

2. 2. METHOD The altitude of centroids (asterixs) above a
- Make images in the
wide energy range
divided into intervals of few keV, in steps of 1 keV.
- Determine positions
of centroids
- Fit the power-law
function:
The altitude of centroids (asterixs) above a
reference level versus the energy of hard X-rays.
The power-law function fit is presented with dotted line.

3. From thick-target model ( ):
Inverse it:
From thick-target model ( ):

4. Brown, J. C., Aschwanden, M. J., and Kontar, E. P., 2002, Solar Phys. 210, 373
Aschwanden, M. J., Brown, J. C., and Kontar, E. P., 2002, Solar Phys. 210, 383
* C7.5
* N16W80
* NOAA 9825

8. 3. RESULTS

9. • PseudoColor picture– the TRACE 171 Å image, obtained after the maximum;
• contours – the TRACE 171 Å images obtained during the impulsive phase, the times are given above each frame;
• crosses – locations of centroids of hard X-ray sources, the times are the same as above, brighter colours represent the higher energies; the solar limb is overplotted.

10. Relations made for consecutive 12s intervals covering the first, main peak.
Time evolution is represented by the brightness. The first interval is the
darkest one.

12. Number of events Number of events Number of events
Thick of the collisional-stopping region [km]

13. Comparision between several models of density (Aschwanden et al
Comparision between several models of density (Aschwanden et al. 2002) and densities obtained from RHESSI observations.

14. 4. QUESTIONS

17. THE END...?