1. -Short Talk-
The soft X-ray characteristics of solar flares, both with and without associated CMEs
Kay H.R.M., Harra L.K., Matthews S.A., Culhane J.L., Green L.M., 2003, A&A, 400, 779
July 14, 2003, Yu Liu

2. Introduction
Complex relationship between flares and CMEs is not clear: case studies, statistical studies
SXR statistical investigation: a close relationship between temperature, emission measure, duration and peak intensity (Harrison 1995, Feldman et al. 1995, 1996, Aschwanden 1999, Veronig et al. 2002), however, they do not differentiate between flares with and without CMEs

3. Purpose of this work
To investigate the relationship between flares and CMEs using a comparison of flare parameters.
With data from:
GOES SXR
LASCO (range of solar radii)
EIT (dimming signatures of CME lower in the corona)

4. Flares selected (69 samples)
Both with and without CMEs
GOES Class B to X
Duration >= 3min
simple events were included
long duration flares with minor events during the decay phase were not excluded
unambiguous determination of whether or not there was an associated CME

5. Flare parameters 1.peak intensity 2.duration 3.peak temperature
4.emission measure
5.EIT wave
peak intensity
1-8 Å
0.5-4 Å
duration
Fig. 1

6. Detection of a CME LASCO EIT (FeXII 195A, dimming)
If insufficient EIT data available, then compare EIT images before and after the event to examine field opening. Only those appeared without no CME were included

7. Results Table 1. mean temperature and flare durations
Table 2. Mean flare duration and peak temperature

8. Table 3. Upper and lower limits of SXR flare characteristics

9. Figure 2. peak intensity vs. duration (69 flares)

10. Figure 3. Peak temperature vs. peak emission measure

11. Figure 4. Peak temperature vs. peak intensity

12. Figure 5. Rise time vs decay time

13. Figure 6. Rise time vs peak temperature

14. Discussion:
How to understand the differences between flares with and without CMEs
For a given peak intensity, flares with CMEs appear to reach lower peak temperatures, suggesting CMEs play the role to remove some energy from the region, so less energy to heat the plasma
For a given peak temperature, flares with CMEs have higher values for the peak emission measure , suggesting a longer time is required to heat the plasma to the give peak temperature
No correlation between peak intensity and duration for flares with CMEs, while a clear correlation for those without CMEs, suggesting CMEs can affect the timescale for energy release and cooling within the flares

15. Conclusion
Clear correlation between peak intensity and duration for flares without CMEs
Same correlation between peak temperature and peak emission measure for these two classes of flares
No difference relationship between rise and decay time
No relationship between the flare rise time and the peak temperature, suggesting…
EIT waves have no correlation between those parameters

16. Further work
To make more complete comparison, we should base on more samples and more wavelengths observations
We will study the HXR properties and non-thermal velocities, using data from Yohkoh
We will make detailed analysis of EIT and TRACE images, because magnetic field morphology may play an important role for a CME occurrence