1. Magnetic Flux Ropes in the Solar Photosphere: The Vector Magnetic Field under Active Region Filaments B.W.Lites the Astrophysical Journal, 622: ,2005, April1
雑誌会　速報2005年10月3日 J. Kiyohara

2. Introduction & Abstract
Where is the helicity of solar atmospheric structures generated ?
 by sheering flows
( Pneuman1983, van Ballegooijen & Martens 1989 etc. )
 by actions in the solar interior

3. Active Region Filaments :　　　 An Observational Diagnostic of Twisted Magnetic Fields
In quiet regions
- Most prominences reside at
heights well above the photosphere.
In the photosphere, strong magnetic fields
are highly buoyant, and this buoyant
force tends to align them with gravity.
( Martinez Pillet et al, 1997,
Parker 1979, pp )

4. Active Region Filaments :　　　 An Observational Diagnostic of Twisted Magnetic Fields
In active regions
- Arch Filaments
upward velocity at the apex of the arch
downwards at the two ends of the arch
roots on opposite sides of the polarity inversion line(PIL)
- very narrow , low-lying filaments
follow along the PIL
This paper focus on filaments in active region plage well separated from sunspots.
the telltale signature of a flux rope
as measured in the vector magnetic field
The concave geometry is a characteristic signature
for a flux rope whose axis has emerged into the
atmosphere.

5. 3. Observational Requirements
-- vector magnetic field measurements
DLSP ( Sankarasubramanian et al )
SOLIS ( Keller et al )
POLIS ( Schmidt et al )
TIP and LPSP ( Martinez Pillet et al )
-- high angular resolution
1”-2” resolution to reveal concave geometry
-- chromospheric diagnostic
Ha Stokes spectra and slit-jaw images of the line core

6. CASE1: An evolving region with persistent concave field geometry
NOAA 8948

7. CASE1: An evolving region with persistent concave field geometry
NOAA 8948
White lines :
separator between positive and
negative polarity magnetic fields
(the PIL).
Yellow lines :
spatially smoothed PIL.
In the vicinity of the PIL,
Field strengths are generally
weaker ( G) and fill factors
are larger than in the plage on either
side ( G ).
April 6-10 :
the photospheric field is generally
aligned with the PIL.
April 6-9 :
the concave geometry

8. CASE1: An evolving region with persistent concave field geometry
NOAA 8948
April 7
White lines :
separator between positive and
negative polarity magnetic fields
(the PIL).
Yellow lines :
spatially smoothed PIL.
In the vicinity of the PIL,
Field strengths are generally
weaker ( G) and fill factors
are larger than in the plage on either
side ( G ).
April 6-10 :
the photospheric field is generally
aligned with the PIL.
April 6-9 :
the concave geometry

9. Orientation of the horizontal component of the magnetic field vector
relative to the local tangent of the PIL.
convex geometry ( frel<0 )
concave-up geometry
( 0 < frel< 180deg. )

10. CASE2: An active filament in NOAA390

11. CASE2: An active filament in NOAA390

12. Discussion
・ The observation presented herein show a qualitatively different vector
magnetic field structure at the PIL than is normally found in plage.
 The magnetic system associated with low-lying filaments has a profound
influence on the magnetic field at the photosphere.
 The likely scenario is that the flux ropes are generated in the solar interior
and buoyantly rise through the photophere into the corona.
・ This first study points to the need for more complete studies that will be
facilitated by new instrumentation for observing solar vector magnetic fields.
 not only the imaging of the chromophere and corona
but also the velocity field in the photosphere and in the chromosphere,
both for Doppler measurements and proper motions.