Neupert effect RHESSI analysis ot the Neupert effect A. Berlicki, R. Falewicz 1) Observatoire de Paris, Section de Meudon, LESIA, FRANCE 2) Astronomical Institute of the Wrocław University, POLAND

Neupert effect The aim of the work: Using the RHESSI data to analyse the Neupert effect within a wide range of the hard X-rays energies. We used 3-second GOES 8 observations to obtain time profiles of the soft X-ray fluxes at high (0.5-4 Å) and low (1-8 Å) channels. Next we calculated time derivatives of both fluxes. The RHESSI X-ray fluxes were obtained in 47 energy bins (channels) of 2 keV width within the energy range keV. The accumulation time was the same as for GOES data (3 seconds). GOES 10 & 12 – problems ?

Neupert effect

For all 24 analysed flares we found the Neupert effect between the hard X-ray emission observed by RHESSI and the soft X-ray emission observed by GOES 8. The time profiles of the GOES soft X-ray derivatives and RHESSI hard X-ray fluxes exhibit high correlations even in the time scale of the order of a few dozen seconds. The correlation depends on the energy. For all flares we found the energy range of RHESSI flux which is highly correlated with the GOES. The RHESSI hard X-ray flux at lower and higher energies is poorer correlated but for stronger flares the correlation coefficients are still high even up to the upper limit of the analysed energy range (100 keV). For smaller flares the correlation coefficient decreases strongly for lower as well as for higher energies than for the energy of maximum correlation. The larger X-ray class of the flare cause that the energy range of the RHESSI flux with maximum correlation is higher. It means that for bigger flares the Neupert effect occurs at higher energies and probably the soft X-ray response is produced by the non-thermal electrons of higher energies.