Transcript LDEフレアにおけるエネルギーとプラズマ供給 - Nobeyama Solar Radio

A New Solar Flare Scenario
- High-beta Plasma Disruption Kiyoto Shibasaki
(Nobeyama Radio Observatory)
2002 July 12
Nobeyama one-day Symposium
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ACTON: I have difficulty thinking of things that I can’t draw
pictures of, and Dr. Zirin’s comment reminds me of something
that has puzzled me for a long time. If one looks at the Halpha image of a larger solar flare, one sees an enormously
complicated and convoluted object in the chromosphere, extending
over a very large area. We now think that this brightening
results from heat conducted from above. This says that in the
corona the hot volumes must be interconnected in a most complex
topology. The means by which this complex topology is
established might be a key to understanding the whole flare
process. I have become convinced that loops are physically
interacting. But if I try to draw a picture of interacting
loops, I find that the interaction can only take place on a
surface. How can appreciable magnetic flux be annihilated
there? The result in any case is that substantial volumes are
filled with hot plasma. How does it get there? It seems to me
that there are things happening to affect the transport of
energy transverse to the field lines, and in a very complicated
topology. I wonder if there is anybody here smart enough to
explain how this happens?
GROUP: (Hollow laughter.)
from Solar Phys. 86 (1983)
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Contents
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Current standard solar flare model
Difficulties with the current model
Flare observations (movies)
Proposal of a new solar flare model (highbeta plasma disruption)
• Application to the observed phenomena
• Further studies
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Current Standard Solar Flare Model
model
Computer simulation
by Yokoyama
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YOHKOH Observation (I)
Soft X-ray Telescope（SXT)
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YOHKOH Observation (II)
SXT
＆HXT
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Difficulties
• How to store all flare energy in a very thin
current layer (we cannot observe due to its
thinness)
• Plasma inflow observation (one candidate)
• How to realize the high energy state and
how to keep it as quasi-equilibrium until
release
• Number problem (thermal, non-thermal)
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Observation by NoRH
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Observation（TRACE/EUV）
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１９９９ Oct. 22 (171Å, 1MK)
2001 Nov. 01
2001 Nov. 27
2001 Sep. 18
2002 Apr. 21
2002 May 27
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Flare Configuration (Non-thermal)
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Flare Scenarios
• Low-beta scenario
– Magnetic free energy
(= current)
– Dissipation by
reconnection
• High-beta scenario
– Plasma free energy
(confinement,
curvature, flow)
– Dissipation by
High-beta disruption
(ballooning instability)
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High-beta Disruption Scenario of
Solar Flares (Shibasaki, ApJ 557, 2001)
• Activities in small loops:
– Small curvature
– High density
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Flows along loops
Activities above loops
Injection from small loop to large loop
Parallel magnetic field configuration
(small, large loops)
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Centrifugal force by thermal motion
and bulk flow V.S. Gravity
gc ＝ ｖ２/R
Bulk flow
Thermal motion
gc/go ~ 6 T6/R9
gc/go ~ 4 V72/R9
go
R9
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Centrifugal Force v.s. Magnetic Tension
Fc
Bulk Flow
Thermal motion
Fc / Ft = 2βk
Fc / Ft = βT
Ft
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Definitions
• βk = (1/2)ρV2 / (B2/8π）
= 2.1 ×N9V72 / BG2
• βT = P / (B2/8π）
= 6.9 ×N9T6 / BG2
• βg = ρgoR / (B2/8π）
=1.1 ×N9R9 / BG2
• κc = 1 / R
• κP = ∂ln(P)/∂ｎ
= 1 / lP
• κB =∂ln(B2/8π）/∂ｎ
= 1 / lB
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Equilibrium and Instability conditions
• Equilibrium at the
outer surface
βTκP +κB =
2κc(1+βg/2‐βk)
• Instability condition
βT＞2（lp/R）・
（ 1+βg/2‐βk ）
• Growth time
τ(s) ~100 √(lp9R9/T6)
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Magnetosphere
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High-beta
Disruption
in Tokamaks
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Prominence Eruption and Ballooning
Ballooning Instability
Prominence Eruption
１７GHｚ
（turbulence, particle accel., ejection,,,）
Spot
Flare ribbons
Event on 1999 Oct. 20
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Summary and Conclusions
• Common Features in Flares and Balloons:
– Turbulence, plasma ejection, high-energy
particle acceleration (upward and downward),
loop top plasma blobs, over-the-loop activity,
impulsive nature, quasi-periodicity in particle
acceleration
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Further Studies
• Beta loading mechanism
• Energetics
• High cadence imaging spectroscopy of
loops at various temperature
• Numerical simulations of non-linearly
developed ballooning instability under solar
coronal condition (3-D)
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LDEフレアにおけるエネルギー
とプラズマの供給
柴崎清登
（NRO)
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LDEフレアにおけるエネルギーとプラズマ供給
• LDEフレア
– 継続時間、温度、RAY構造、
Inflow(YOHKOH, SoHO/LASCO)
• 磁気再結合シナリオ
• Inflow によるエネルギーとプラズマの供給
– 継続時間と温度
• 高ベータ崩壊シナリオとの関係
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LDEフレア
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プロミネンス崩壊 / CME, Two ribbon flare
継続時間：数時間～1日
温度：８百万度、一定
RAY構造：YOHKOH／SXT
Inflow
– RAY構造に沿った下降流 (YOHKOH/SXT)
– 上空コロナでの下降流 (SoHO/LASCO)
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Inflowによるエネルギーとプラズマの供給
• 位置エネルギー
⇒運動エネルギー
⇒熱エネルギー
mpgoRo h
h
• T= ――― ――
T6=7.7 × ――
3kB
h+1
h+1
• プロミネンスの質量 ： 位置エネルギー
2×1015ｇ ～ 4×1030erg
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高ベータ崩壊シナリオとの関係
プロミネンス上昇
上空のアーケード磁場に衝突
バルーニング（櫛状のfingers）
Fingersの上昇 ： RAY構造
上昇しきれなかったプラズマの下降
LASCO: inflow & SXT: inflow
6. 位置エネルギーの解放とプラズマの供給
長時間（LDE),一定温度（８MK)のプラズマ供給
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