caa a22 4500 445346566 CHVBK 20180317142830.0 cr unu---uuuuu 170323e20110301xx s 000 0 eng 10.1007/s11207-010-9690-5 doi (NATIONALLICENCE)springer-10.1007/s11207-010-9690-5 On Integrated Hard X-Ray Broken-Up Spectra ofSolarFlares [Elektronische Daten] [Y. Li, W. Gan] The summation of two single power-law spectra with a rather big difference of the spectral indices and with comparable intensities looks like a broken-up spectrum. The spatially integrated hard X-rays contain contributions from different sources, like footpoint and looptop sources. Within the standard scenario of solar flares, the power-law index difference between the footpoints and looptop should betwo. Taking the M7.6 flare on 24October 2003 as an example, we showed that the hard X-ray spectrum itself for footpoints and looptop is a single power-law, but the spatially integrated spectrum presents a broken-up form. It is also shown that the time-integrated spectrum could present a broken-up form, although the spectrum in further refined intervals presents a single power-law. It is concluded that the integrated broken-up spectrum observed here is produced either by the summation of individual sources or by the temporal variation of a single source, not by the acceleration itself. Springer Science+Business Media B.V., 2010 Flares, spectrum nationallicence Spectrum, X-ray nationallicence X-ray bursts, hard nationallicence Li Y. Purple Mountain Observatory, Chinese Academy of Sciences, 210008, Nanjing, China aut Gan W. Purple Mountain Observatory, Chinese Academy of Sciences, 210008, Nanjing, China aut Solar Physics Springer Netherlands 269/1(2011-03-01), 59-66 0038-0938 269:1<59 2011 269 11207 https://doi.org/10.1007/s11207-010-9690-5 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11207-010-9690-5 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Li Y. Purple Mountain Observatory, Chinese Academy of Sciences, 210008, Nanjing, China aut NATIONALLICENCE 700 1- Gan W. Purple Mountain Observatory, Chinese Academy of Sciences, 210008, Nanjing, China aut NATIONALLICENCE 773 0- Solar Physics Springer Netherlands 269/1(2011-03-01), 59-66 0038-0938 269:1<59 2011 269 11207 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer