A flare compilation
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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.

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A flare compilation

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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


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.

Following filament eruption

Harra et al., 2005

Pre-eruption stage


CDS

SOHO/CDS slit

Position

Fe XIX Doppler velocity

Fe XIX intensity

Flux rope

Vl < 0

Flux rope

Vl > 0

Flare loops

Flare loops

Time  13:0015:00

Time 

Synthetic slit image made of TRACE data

TRACE EUV image

SOHO/CDS observations


rotated and tilted to event location

flare time

disc centre view

Magnetic modelling

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.


position

Fe XIX Doppler velocity

Vl<0

Vl>0

time

Combining modelling results with CDS Doppler shift

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


RHESSI observations:

Moving (rising) coronal X-ray source

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.

v≈60 km/s

Looptop source

Rising coronal source


Erupting filament (TRACE)

Rising X-ray source

(RHESSI)

Height-time plots - low corona

CDS obser-

vation

• 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 - TRACE & C2

Height-time plot

of CME leading

and trailing edges

in LASCO/C2 images

Height-time plot

of lifting filament

in TRACE images

vCME ~ 120 km s-1

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.


Blabla

blabla

Blab l

Height-time plot, low corona

Exponential growth

Height-time plot, high corona

EUV flux rope

v~45-75 km/s

LASCO/C2

v~120 km/s

LASCO/C2

RHESSI source

~60 km/s

TRACE

v~60 km/s

• New evidence for flux rope structure of an erupting filament

• Linking a rising RHESSI

coronal 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.

Contour:

RHESSI

10-15 keV

SOHO/CDS slit

position

Fe XIX Doppler velocity

Flux rope

Vl<0

+

Vl>0

Cooling loops

magnetic extrapolation 

3-D flare loop orientation

TRACE EUV image

A&A 434, 761 (2005)

time


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