what can we learn from the vector magnetic field measured in filament channels ?
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The 6th Solar-B Science meeting Kyoto Nov 8 2005
What can we learn from the vector magnetic
field measured in filament channels ?
Arturo López AristeB. Schmieder, G. Aulanier,
THEMIS Observations:Magnetic field vector
Introduction
Chirality and resolution of the 180° ambiguity
The 6th Solar-B Science meeting Kyoto Nov 8 2005
Barbs and feet are related to Minority magnetic polarities (Martin 1994)
Lin , Wiik, Engvold (2004, 2005) 60% of ends are rootedin network boundaries
How is oriented the field vector?Is it horizontal (Chae et al 2005)
or vertical (Lin et al 2005) ?
SST La Palma
The 6th Solar-B Science meeting Kyoto Nov 8 2005
Computations of the dips in each field line in the computation model box
ligne de champ
dH = Hg = 300 km
altitude (z)(B . ) B > 0
Bz = 0
Presence of minority polarities in filament channels
Simulation of the observations of cool plasma visible in multi- (Aulanier and Démoulin 1998, van Ballegooijen 2004, Régnier and Amari 2004)
Dips filled by plasma
The 6th Solar-B Science meeting Kyoto Nov 8 2005
Extrapolation of B from SoHO/MDI
3D magneto-hydrostatic linear model with free parameters constrained by the theory and the observations
08:12 UT 07:52 UT
Lignes de champ
filament
arcades coronales
Matière froide
z > 4 Mm
z < 4 Mm
Topology of B and distribution of the cool matter Aulanier G., Schmieder B., 2002, A&A, 386, 1106-1122
CDS OV
THEMIS
The 6th Solar-B Science meeting Kyoto Nov 8 2005
Modeled dipsAdapted from
Aulanier et al. (1999)
H filament Bz (z=0) & Magnetic dips
Bt (z=0)
Dipsviewed in 3D
–+
barb
The 6th Solar-B Science meeting Kyoto Nov 8 2005
THEMIS
JOP 178 International campaign 16 October 2004
The 6th Solar-B Science meeting Kyoto Nov 8 2005
THEMIS Observations in the Multi lines mode
1. Simulaneously observations of the polarized profiles ofFe I doublet 6301-6302 A, Na I, Hwith beam exchange techniqueData processing (flat field, dark current) SQUV3. Inversion code for the Fe I doublet with a PCA-based algorithmin a Milne-Eddington atmosphere using a grid of models B, Inc., Azi. with error bars in the LOS ref. frame4. Change of the system of reference to local frame5. The 180 ° ambiguity is not resolved, two solutions for incl. and azi.
Criterion used for resolving the ambiguity : the chirality rules for filaments
The 6th Solar-B Science meeting Kyoto Nov 8 2005
SINISTRAL CASE DEXTRAL CASE
According to the directions of the fine structures and the feet (Halpha)
Filament
The 6th Solar-B Science meeting Kyoto Nov 8 2005
I(H)
B (Fe I)
B Sinistral filament
The 6th Solar-B Science meeting Kyoto Nov 8 2005
+
–
Filament axisPhotospheric inversion line (Bz)
SINISTRAL CASE
B horizontal mean direction if the chirality is sinistral
The 6th Solar-B Science meeting Kyoto Nov 8 2005
+
–
B horizontal mean direction if the chirality is dextral
DEXTRAL CASE
Filament axisPhotospheric inversion line (Bz)
The 6th Solar-B Science meeting Kyoto Nov 8 2005
#1#5
#3 #4
#2
#6
The 6th Solar-B Science meeting Kyoto Nov 8 2005
#1#5
#3 #4
#2
#6
The 6th Solar-B Science meeting Kyoto Nov 8 2005
114.7 Mx/cm2 -8.8 Mx/cm2
The 6th Solar-B Science meeting Kyoto Nov 8 2005
Inversion errors (case #1)
The 6th Solar-B Science meeting Kyoto Nov 8 2005
Case #1
–+
3D
The 6th Solar-B Science meeting Kyoto Nov 8 2005
Case #1 3D view
In the filament channel : horizontal dip
Case 2
Case 4
Case 5
The 6th Solar-B Science meeting Kyoto Nov 8 2005
Bz & Bt (z=0)
Lopez Ariste, Aulanier, Schmieder , Sainz A &A 2006
H filament
–+barb
Dipviewed in 3D
The 6th Solar-B Science meeting Kyoto Nov 8 2005
Conclusion
THEMIS/MTR observes simultaneously in multi lines: H, Fe 6302 and 6301, Na D1
High sensitivity of the magnetic flux: -10 Mx/cm2
Magnetic field vector tangential to the photosphere
Photospheric dips = « bald patches » observed
in filament channels
consistent with model of Aulanier & Démoulin (1998)
Needs more cases : SOLAR-B
The 6th Solar-B Science meeting Kyoto Nov 8 2005
Observational evidence of photospheric magnetic dips
in filament channels
Arturo López AristeB. Schmieder, G. Aulanier,
Magnetic loops
filament flux tube
overlaying arcades
Magnetic dips
z > 4 Mm
z < 4 Mm
Adapted from Aulanier & Schmieder (2002)
The 6th Solar-B Science meeting Kyoto Nov 8 2005
EUV filament
A
C
C
ADark, bright threads or no existing
Emission in hot lines
B BOV 105 K
Long extensions
The 6th Solar-B Science meeting Kyoto Nov 8 2005
Case # 6
The 6th Solar-B Science meeting Kyoto Nov 8 2005
Conclusion
THEMIS/MTR observes simultaneously in multi lines: H, Fe 6302 and 6301, Na D1
THEMIS/MSDP H and Na D1 High sensitivity of the magnetic flux: -10 Mx/cm2
Magnetic field vector tangential to the photosphere
Photospheric dips = « bald patches » observed
in filament channelsconsistent with the model of Aulanier & Démoulin (1998)
1.
2. Emerging and cancellation of magnetic fluxFilament disappearance and formation
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