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Causal Relationships Between Eruptive Prominences and Coronal Mass Ejections

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Causal Relationships Between Eruptive Prominences and Coronal Mass Ejections Ann. Geophys., 26, 3025–3031, 2008 www.ann-geophys.net/26/3025/2008/ Annales © European Geosciences Union 2008 Geophysicae Causal relationships between eruptive prominences and coronal mass ejections B. Filippov1 and S. Koutchmy2 1Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation, Russian Academy of Sciences (IZMIRAN), Troitsk Moscow Region, Russia 2Institut d’Astrophysique de Paris, CNRS and Univ. P.& M. Curie, Paris, France Received: 17 September 2007 – Revised: 23 November 2007 – Accepted: 27 November 2007 – Published: 15 October 2008 Abstract. A close association between eruptive prominences 1 Introduction and CMEs, both slow and fast CMEs, was reported in many studies. Sometimes it was possible to follow the material mo- Hα observations of the activation of a filament (prominence) tion starting from the prominence (filament)1 Introduction activation to the frequently end up suddenly due to the shift of this line from CME in the high corona. Remnants of the prominence were the filter pass-band due to i) the Doppler effect, ii) the de- found in the bright core of the CME. However,Hα observations detailed com-of the activationcrease ofof thea filament emission (prominence) due to the decreasefrequently in end the up density suddenly of due parisons of the two phenomena reveal problemsto the shift in explainingof this line fromexpanding the filter pass-band material, anddue to iii) i) thethe ionizationDoppler effect, of hydrogen ii) the decrease due of CMEs as a continuation of filament eruptions in the upper to the heating of the prominence plasma. The subsequent corona. For example, the heliolatitudesthe of emission the disappeared due to the decreaseevolution in th cane density sometimes of expanding be observed material, in ultraviolet and iii) the or ionization radio, of filaments and subsequent coronal ejectionshydrogen sometimes due to differ the heatingbut theof fatethe ofprominen a prominencece plasma. usually The becomessubsequent visible evolution only can by tens of degrees. In order to clear up the problems ap- when it reaches the lower boundary of the field of view of a sometimes be observed in ultraviolet or radio, but the fate of a prominence usually becomes pearing when considering this association EP-CME, we ten- coronagraph and becomes visible in white light as a coronal tatively analyse the more general questionvisible of the only dynamics when it of reachesmass the ejection lower boundary (CME). A of typical the field CME of consistsview ofof a threecoronagraph parts: and the generic magnetic flux rope. Prominencesbecomes and visible filaments in white lighta bright as a corecoronal that ma isss the ejection remnant (CME). of an eruptiveA typical prominence CME consists of are the best tracers of the flux ropes in the corona long be- (EP); a large, dark, lower-density surrounding cavity; and an fore the beginning of the eruption. Athree twisted parts: flux a bright rope is core thatouter, is ratherthe remnan diffuset of envelope an eruptive having prominence the projected (EP); shape a large, of a dark, held by the tension of field lines of photosphericlower-density sources surrounding until closedcavity; loop and withan outer, its legs rather fixed diffuse on the envelope Sun (Crifo having et al, the 1983; projected parameters of the system reach critical values and a catastro- Sime et al., 1984). shape of a closed loop with its legs fixed on the Sun (Crifo et al, 1983; Sime et al., 1984). phe happens. We suggest that the associated flux rope height There is a very close association between eruptive promi- above the photosphere is one of these parametersThere is anda very that close it is associationnences andbetween CMEs. eruptive There prominences are no doubts, and that CMEs. in ejections There are no revealed by the measured height of the filament.doubts, that 80 filamentsin ejections withwith br brightight cores, cores, the the material material of er ofuptive eruptive prominences prominences is contained is were analysed and we found that eruptive prominences were contained in the cores (House et al, 1981). Figure 1 shows an near the so-called limit of stability a fewin the days cores before (House their et al,example 1981). ofFigure event 1 when show ans an eruptive example prominence of event was when recorded an eruptive eruptions. We suggest that a comparisonprominence of actual heights was recorded of inin He II 304 304 Ǻ lineline with with the the ultraviolet ultraviolet telescope telescope EIT EIT on on SOHO, prominences with the calculated critical heights from mag- SOHO, and then the remnants of the twisted prominence and then the remnants of the twisted prominence were well recognised in the core of the netograms could be systematically used to predict filament were well recognised in the core of the CME up to a dis- eruptions and the corresponding CMEs.CME up to a distance oftance several of severalsolar radii solar from radii the from surface. the surface. Another Another example exam- (Fig. 2) Keywords. Solar physics, astrophysics,indicates and a astronomygood correspondenceple (Fig. in 2)time, indicates spatial aposition good correspondence and direction of in motion time,spa- of an EP (Corona and transition region– Flares and mass ejections – tial position and direction of motion of an EP filament and a filament and a CME. Even in the case of a limb CME observed at the time of a solar total Magnetic fields) CME. Even in the case of a limb CME observed at the time of eclipse, when the inner anda the solar outer total white-light eclipse, when corona the are inner both and well the imaged, outer white-light this association corona are both well imaged, this association is obvious (see is obvious (see Koutchmy et al., 2004) including the occurrence of a high loop/cavity Koutchmy et al., 2004) including the occurrence of a high association. At the same time,loop/cavity there are association. ejections without At the bright same core, time, or events, there are for ejec-which it is impossible to find the presumedtions without prominence bright core, eruption or events, or filament for which disappearance. it is impos- The Correspondence to: B. Filippov sible to find the presumed prominence eruption or filament (bfi[email protected]) opposite, when a CME isdisappearance. absent after a The filament opposite, eruption, when was a CME reported. is absent However after this happens in the case of "confined" eruptions, when the filament does not fly away too far but Published by Copernicus Publications onstops behalf at some of the height European in a Geosciences new equilibrium Union. position (Vrsnak et al., 1990; Filippov and Koutchmy, 2002; Torok and Kliem, 2005; Alexander et al., 2006). Thus, the relationship between these two phenomena is not always obvious, and it is the subject of analysis in many works. The purpose of this paper is to discuss these and some other problems of EP-CME association and try to resolve them in the frame of a magnetic flux rope model. 2 3026 B. Filippov and S. Koutchmy: Eruptive prominences and coronal mass ejections Fig. 2. Eruptive process on 25 Aug 2003 shown in subsequently in- creasing scale. White light SOHO/LASCO C2 corona at 04:26 UT (left), SOHO/EIT Fe XII 195 line image at 02:24 UT (middle), and TRACE Fe IX 171 line image at 02:26 UT (right). Erup- tive filament just after the start of ascending motion is seen as dark semicircular feature at the upper-right corner of the TRACE filter- Fig. 1. Polar crown filament eruption on 14 June 1999 visible in gram. (Courtesy of SOHO/EIT, SOHO/LASCO, and TRACE con- SOHO/EIT He II 304 line (top row) and the following CME ob- sortiums. SOHO is a joint ESA-NASA project. TRACE is a mis- served with LASCO C2 (bottom row). (Courtesy of SOHO/EIT and sion of the Stanford-Lockheed Institute for Space Research (a joint SOHO/LASCO consortiums. SOHO is a joint ESA-NASA project.) program of the Lockheed-Martin Advanced Technology Center’s Solar and Astrophysics Laboratory and Stanford’s Solar Observato- ries Group) and part of the NASA Small Explorer program.) a filament eruption, was reported. However, this happens in the case of “confined” eruptions, when1 the filamentIntroduction does not fly away too far but stops at some height in a new equilib- Hα observations of the activation of a filament (prominence) frequently end up suddenly due rium position (Vrsnak et al., 1990; Filippov and Koutchmy, The choice of data used in the correlation analysis can 2002; Torok and Kliem, 2005; Alexanderto etthe al., shift 2006). of this Thus, line fromprobably the filter influencepass-band the due result. to i) the For Doppler example, effect, a low ii) the correla- decrease of tion of 10–30% between CMEs and prominence eruptions the relationship between these two phenomenathe emission is not due always to the decrease in the density of expanding material, and iii) the ionization of obvious, and it is the subject of analysis in many works. together with sudden filament disappearances was obtained by Yang and Wang (2002); it is possibly a consequence of The purpose of this paper is to discusshydrogen these due and to some the heating of the prominence plasma. The subsequent evolution can including thermal disappearances of filaments not connected other problems of EP-CME associationsometimes and try tobe resolveobserved in ultraviolet or radio, but the fate of a prominence usually becomes with dynamic events into the data set (Mouradian et al., them in the frame of a magnetic flux rope model. visible only when it reaches1995). the lower In the boundary same period of the of time,field of 82% view of eruptiveof a coronagraph promi- and becomes visible in white lightnences as a observed coronal ma withss ejection the Nobeyama (CME).
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