A flare compilation
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Transcript of A flare compilation
A flare compilation
• Lots of people including Louise Harra, Lidia van Driel Gesztelyi, Chris Goff, Sarah Matthews, Len Culhane, Cristina Mandrini, Pascal Demoulin, Lyndsay Fletcher
15 Jul 02 – two filament eruptions and a couple of CMEs
Spectroscopic evidence for break-out
• In contrast to the standard model reconnection starts high in the corona.
• Evidence has been found in the form of remote brightenings (and flows) prior to the impulsive phase.
Gary and Moore., 2004, Harra et al. 2005
Sterling and Moore
Pre-eruption stage Following filament eruption
Spatially resolved evaporation has been observed in various cases now e.g .Brosius and Phillips (2004) with velocities 10s km/s and del Zanna et al (2005) with velocities reaching 140 km/s.
Harra et al., 2005
SOHO/CDS slit
TRACE EUV image
Fe XIX Doppler velocity
Vl < 0
Vl > 0
Time 13:00 15:00
Flare loops
Flux rope
Fe XIX intensity
Flux rope
Flare loops
Time
Position
CDS
Synthetic slit image made of TRACE data
SOHO/CDS observations
disc centre view
rotated and tilted to event location
view tilted to show arcade orientation
Magnetic field lines extrapolated in the linear force-free approximation (=0.015 Mm-1)using a SOHO/MDI magnetic field map on 14 April in order to determine the 3-D spatial orientation of the flare loop and deduce the direction of plasma flows from the Doppler data.
flare time
Magnetic modelling
Vl>0
Vl<0
time
position
Fe XIX Doppler velocity
S leg points away from us - Red-shifted in CDS N leg points towards us - Blue-shifted in CDS
Plasma is flowing down along both legs of the flare loops
Combining modelling results with CDS Doppler shift
RHESSI 10-15 keV contours (made with PIXON) over TRACE images show a rising coronal X-ray source.
Images made in the 5-10 keV and 15-20 keV ranges show very similar motion pattern.
RHESSI observations:Moving (rising) coronal X-ray source
Looptop source Rising coronal source
v≈60 km/s
Erupting filament (TRACE)
Rising X-ray source(RHESSI)
• Height - time plot of the lifting flux rope as seen by TRACE. • The cross in the red circle represents the leading edge of the flux rope as seen by CDS. • Below the best-fit lines are data points from the coronal hard X-ray source.
• HXR RHESSI light curve between 5-50 keV.
Height-time plots - low corona
CDS obser-vation
Height-time plotof lifting filamentin TRACE images
Height-time plotof CME leading and trailing edgesin LASCO/C2 images
An exponential growth makes the link between the two curves, while neither the linear nor the polynomial fit can reach the required height by the C2 appearance time of the CME.
Height-time plots - TRACE & C2
vCME ~ 120 km s-1
Vl>0
Vl<0Flux rope
SOHO/CDS slit
TRACE EUV image time
position
Fe XIX Doppler velocity
Cooling loops
+
magnetic extrapolation 3-D flare loop orientation
• New evidence for flux rope structure of an erupting filament
• Linking a rising RHESSIcoronal source to the erupting filament
• New evidence for exponential growth of CMEs in the low corona - result of kink instability?
• Results consistent with down-flows of hot plasma along both loop legs.
RHESSI source~60 km/s
LASCO/C2 v~120 km/s
Blablablabla
Blab l
Height-time plot, high corona
TRACE
LASCO/C2
Contour:RHESSI10-15 keV
EUV flux ropev~45-75 km/s
Exponential growth Height-time plot, low corona
v~60 km/s
A&A 434, 761 (2005)