Počet záznamů: 1
Spectroscopic Diagnostics of the Non-Maxwellian kappa-distributions Using SDO/EVE Observations of the 2012 March 7 X-class Flare
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SYSNO ASEP 0494688 Druh ASEP J - Článek v odborném periodiku Zařazení RIV J - Článek v odborném periodiku Poddruh J Článek ve WOS Název Spectroscopic Diagnostics of the Non-Maxwellian kappa-distributions Using SDO/EVE Observations of the 2012 March 7 X-class Flare Tvůrce(i) Dzifčáková, Elena (ASU-R) RID, ORCID
Zemanová, Alena (ASU-R) ORCID, RID
Dudík, Jaroslav (ASU-R) RID, ORCID
Mackovjak, Šimon (ASU-R)Číslo článku 158 Zdroj.dok. Astrophysical Journal - ISSN 0004-637X
Roč. 853, č. 3 (2018)Poč.str. 13 s. Forma vydání Online - E Jazyk dok. eng - angličtina Země vyd. US - Spojené státy americké Klíč. slova data analysis ; radiation mechanisms ; non-thermal Vědní obor RIV BN - Astronomie a nebeská mechanika, astrofyzika Obor OECD Astronomy (including astrophysics,space science) CEP GA17-16447S GA ČR - Grantová agentura ČR GA18-09072S GA ČR - Grantová agentura ČR Institucionální podpora ASU-R - RVO:67985815 UT WOS 000424011300019 EID SCOPUS 85041917126 DOI 10.3847/1538-4357/aaa426 Anotace Spectroscopic observations made by the Extreme Ultraviolet Variability Experiment (EVE) on board the Solar Dynamics Observatory (SDO) during the 2012 March 7 X5.4-class flare (SOL2012-03-07T00: 07) are analyzed for signatures of the non-Maxwellian kappa-distributions. Observed spectra were averaged over 1 minute to increase photon statistics in weaker lines and the pre-flare spectrum was subtracted. Synthetic line intensities for the.distributions are calculated using the KAPPA database. We find strong departures (kappa less than or similar to 2) during the early and impulsive phases of the flare, with subsequent thermalization of the flare plasma during the gradual phase. If the temperatures are diagnosed from a single line ratio, the results are strongly dependent on the value of kappa. For kappa =. 2, we find temperatures about a factor of two higher than the commonly used Maxwellian ones. The non-Maxwellian effects could also cause the temperatures diagnosed from line ratios and from the ratio of GOES X-ray channels to be different. Multithermal analysis reveals the plasma to be strongly multithermal at all times with flat DEMs. For lower kappa, the DEM kappa are shifted toward higher temperatures. The only parameter that is nearly independent of. is electron density, where we find log n(e) [cm(-3)]) approximate to 11.5 almost independently of time. We conclude that the nonMaxwellian effects are important and should be taken into account when analyzing solar flare observations, including spectroscopic and imaging ones. Pracoviště Astronomický ústav Kontakt Radka Svašková, bibl@asu.cas.cz, Tel.: 323 620 326 Rok sběru 2019
Počet záznamů: 1