A&A 433, 1133-1138 (2005)
Multispacecraft observations of the hard X-ray emission from the giant solar flare on 2003 November 4S. R. Kane, J. M. McTiernan and K. Hurley
Space Sciences Laboratory, 7 Gauss Way, University of California, Berkeley, 94720-7450, USA
(Received 19 August 2004 / Accepted 20 December 2004)
The hard X-ray emission from the "giant" solar flare on 4 November 2003 (~1947 UT) was observed by the hard X-ray/gamma ray spectrometer on the Ulysses spacecraft located at ~114 degrees west of the Sun-Earth line at a distance of 5.28 AU from the Sun. A "small" hard X-ray burst during the early rise of the giant flare and a part of the decay of the hard X-ray emission associated with the giant flare were also observed by the hard X-ray imager on the RHESSI satellite located near the Earth. The maximum of the hard X-ray emission during the giant flare could not be observed by the RHESSI instrument because of satellite night. The flare view angles for Ulysses and RHESSI were ~31 West and 83 East respectively. The H- flare (importance 3B) was located at S19 W83 in the active region NOAA 10486. GOES observations of the associated soft X-ray emission saturated during the period 1943-1958 UT. It has been estimated that the soft X-ray maximum occurred at ~1947 UT with peak flux equivalent to NOAA class X28. OVSA radio observations show that the flare produced intense microwave emission, the peak flux at 15.4 GHz being ~60 000 sfu at ~1945 UT. Intense type II, III and IV radio bursts have also been reported at metric and decimetric wavelengths. RHESSI has provided 10-100 keV X-ray images and spectra for 1930-1936 UT (the early rise of the flare) and 10-30 keV images and spectra for 2016-2114 UT (a part of the late decay of the flare). Ulysses observed an increase in 25-150 keV X-rays from 1933 UT to 2015 UT with the maximum at ~1944 UT, almost simultaneously with the maximum in 15.4 GHz radio emission and ~3 min before the maximum in the soft X-ray emission. This indicates that the X-ray emission observed by Ulysses was mostly non-thermal. An assumed hard X-ray spectrum of ~ for >20 keV photons leads to an energy dissipation rate of at the time of the hard X-ray maximum. The total energy in >20 keV electrons released during the flare is estimated to be ~ .
Key words: Sun: activity -- Sun: flares -- Sun: X-rays -- gamma rays
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