Solar-­‐Cで探る	  磁気リコネクションの物理	

Shinisuke	  Imada	  (Nagoya	  Univ.,	  STEL)	

Plasmas	  condiAons	  in	  solar	  corona	Weak Collision Plasma	Diﬀerence	  from	  collisionless	  plasma		  • Momentum	  transfer	  by	  coulomb	  collision	  衝突による運動量交換	

• Thermal	  conducAon	  along	  magneAc	  ﬁeld	  衝突による熱伝導	• IonizaAon	  and	  recombinaAon	  衝突による電離・再結合	

• RadiaAve	  energy	  loss	  (not	  synchrotron	  radiaAon)	
衝突による輻射	What plasma parameter control theenergy conversion rate?	

Target	  of	  MRX	  obs.	
• HeaAng	  associated	  with/without	  slow-­‐shock.	  	  	  	  	  	  	  	  	  	  	  	  	  Electron	  heaAng	  	  	  	  	  	  	  	  	  	  	  	  	  Ion	  heaAng	  (Possible???)	  • Alfvenic	  ﬂow	  	  	  	  	  	  	  	  	  	  	  	  	  Doppler	  shiS	  measurement	  	  	  	  	  	  	  	  	  	  	  	  	  IonizaAon	  informaAon	  	  • ParAcle	  acceleraAon	  	  	  	  	  	  	  	  	  	  	  	  	  Supra-­‐thermal	  &	  High	  energy	  electron	  acc.	

8Standard	  model	  for	  Solar	  Flare	
Hot & Fast Flow should be observed!
CHAPTER 10. MAGNETIC RECONNECTION

with Solar-C

with Yohkoh and Hinode

Yokoyama&Shibata
2001

gure 10.21: Elaborate version of the standard 2D X-type reconnection model that also in-Tsuneta et al., 1996

des the slow and fast shocks in the outflow region, the upward-ejected plasmoid, and theations of the soft X-ray bright flare loops (Tsuneta 1997).

erating particles in a downward direction and producing shock waves and plasmoid

Hara	  et	  al.	  2011	  ApJ	  RX	  ﬂows	

hysical Journal, 741:107 (20pp), 2011 November 10(a)

(c)

(b)

(d)

(e)

Line-of-sightdirection

Wt~20 deg

Direction ofEIS raster scanNpatial relationships among (a) Fe xii 195 line-of-sight Doppler velocity VD showing an inflow structure to a site near S1, (b) enhancement
index as a signature of hot outflows, and (c) electron density from the intensity line ratio of Fe xii 186/Fe xii 195. (d) Schematic picture olocity observations near the loop-top region with the RHESSI 4–6 keV thermal source at 12:50:30–12:52:30 UT in green contours. (e) Int

Spectroscopic	  obs:	  EIS	  Line	  Proﬁles	-400 km/s	

Imada et al., 2013 ApJL

0 km/s	

400 km/s	Thermal	  Non-­‐Equilibrium	  Plasma	Because RX is highly dynamic, plasma may not reached toEquilibrium stage! This is new regime for Solar physics obs.

• Non-­‐Gaussian	  DistribuAon	  funcAon	  	  	  	  	  	  	  	  ガウス分布でない		  	  	  	  	  	  	  	  → Power-­‐law	  distribuAon,	  beam	  plasma	  	  	  	  	  	  	  	  	  Ame	  scale	  for	  equilibrium	  is	  very	  short	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  (kineAc	  regime	  or	  e-­‐e	  or	  i-­‐i	  collision)	  • Diﬀerent	  temperature	  in	  diﬀerent	  species	  	  	  →	  Ti>Te	  	  	  	  	  	  	  	  	  Ame	  scale	  for	  equilibrium	  is	  relaAvely	  long	  	  	  	  	  	  	  	  	  	  (e-­‐i	  collision)	  プラズマ種で平衡でない	
• IonizaAon	  non-­‐equilibrium	  	  	  	  →	  strong	  heaAng	  or	  ﬂare	  電離非平衡		  	  	  	  	  	  	  Ame	  scale	  for	  equilibrium	  is	  long	  IonizaAon	  Process	
Fe13+
FeXIV

Fe14+
FeXV

Fe15+	FeXVI	

ionization	

αS

Fe16+

Fe17+	FeXVIIFeXVIII	

recombination	

collisional and dielectronic recombination
collisional ionization	

We can discuss the history of heating!

Example	  of	  IonizaAon	  CalculaAon	

ournal, 742:70 (11pp), 2011 December 1

time-dependent ionization in magneticInitialreconnection(Run1). TimeEquilibrium
starts from shock crossing. The calculation was carri: Ionization

Te: 1.5 MK à 31.3 MK @ t=0
Ne: 2.45 x 10^9 /cc	figure is available in the online journal.)

Table 1
ow-Mode Shock Jump Conditions

The continuity equations for iron are expres

How	  to	  diagnose	  MRX	  region?	
Slow-mode ShockIonization process with line spectroscopy
Spatial resolution is enough to resolve.
Scanning time <100s

Fast scanning (<Alfven time~100s)
with high throughput spectrometer.
Wide temperature coverage.
Diagnose velocity, temperature, densitywith spectroscopic observation!
Imada et al., 2011 ApJ

How	  to	  diagnose	  MRX	  region?	

10sec:L2	
1sec:L1	

Density:	  Line	  raAo	  	  (L2-­‐L1)/9=v1	  (L3-­‐L2)/70=v2	  80sec:L3	 Assume	  V1~V2	  Te	  and	  V	  can	  be	  inverted.	

Sweet-­‐Parker	  .vs.	  Petschek	  RX	  	Bhattacharjee+, 2009
Sweet-Parker like RX
Heating is localized
inside CS
Yokoyama&Shibata, 1997

1. "Color online# Time-sequence of the nonlinear evolution of the current density Jy of a Sweet–Parker current sheet in a large system of Lundquist
er SL = 6.28! 105. The black lines represent surfaces of constant ".

s to settles down to a plateau, until about t ! 9. At thisof the third nonlinear phase, some of the small islands
uced by the secondary instability coalesce to form larger
ds that are convected toward the boundaries. "If the iss grow to large size but are constrained to stay fixed atenter of the computational domain by reason of symmeimposed in the simulations, the third nonlinear phasebe short-lived, and the reconnection rate may fall rapAt about this point in time, the extended current sheet
ws yet another burst of secondary tearing activity producmultiple plasmoids, and a consequent enhancement in thennection rate, which at about t ! 12 attains nearly anorder of magnitude higher than the Sweet–Parker rate at thisvalue of SL. Due to insufficient spatial resolution, caused by
the slow drift of the current sheet away from the region
where the grid points along z are clustered, we are not able tocarry these simulations forward longer in time.
The plasmoid instability of Sweet–Parker sheets occurs
after SL exceeds a critical value, determined numerically tobe approximately 3 ! 104 in the present study. Like the blackcurve, the blue dashed curve in Fig. 2 corresponds to anothervalue of SL "=2.51! 105# above the threshold and shows
generically similar behavior, while the red dashed curve corresponds to a value "=3.14! 104# at about the threshold. WePetschek RX

Heating region is larger
by Slow-mode Shock etc.

s copyrighted as indicated in the article. Reuse of AIP content is subject to the terms at: http://scitation.aip.org/termsconditions. Downloaded to IP:
133.47.145.22 On: Sun, 03 Aug 2014 04:20:26

まとめ	• Solar-­‐Cでは格段にeﬀecAve	  area	  が大きくなる	  • 高時間分解能で観測が可能になる	  • 多波長での分光観測	  • 迷光・散乱光等のノイズを極力軽減	  • 電離過程から加熱の履歴（時間）を診断する事を目指す	  • Forward	  modeling	  または	  inversionから短い時間スケールの現象を診断可能に！	

Strategy	  to	  solve	
Part3	  RadiaAon	Part1	  IonizaAon	

Part2	  HD、MHD	  One,	  or	  Two	  ﬂuid？	

T, N, V	 T、V、N、ﬁelds	
Obs.	

Rad.	

Ionization	
IonizaAon	
Rad.	  E.	  loss	

T, N, V	 T、V、N、ﬁelds	
Ionization	
IonizaAon	
Obs.	

Rad.	

Rad.	  E.	  loss	電離非平衡計算結果	
初期条件：電離平衡	

FeXII	FeXXI	

点線：電離平衡	  実線：電離非平衡	  FeXV	FeXXIV	RX	  2D	  calculaAon	  +	  Time	  dependent	  ionizaAon	
MHD	
Ne	
Te	
Vx	

Ionization	
FeXII	FeXVII	FeXXI	Vz	FeXXVI	

We have to improve our code in some points(e.g., numerical diffusion).

Coronal	  HeaAng	  :ObservaAon	  Ion	  Temperature	Imada et al., APJL 2009

彩層蒸発計算	  CANS	HYDRODYNAMI

パラメータ

変数

無次元値

有次元値ループ半長

Lxtr
Tcor
Hf0

130
12.5200
5 × 10−426000 km
2500 km2 MK3 erg cm−3 s−1Tcl
ncl

2010−52 × 105 K
1012 cm−3T0
ρ0H0111104 K
1017 cm−3200 km

111/γ

10 km/sreconnect to close and accumulate on the lower-lying close
20 s of the closed loops increases. The total energy release rate
2 hatched regions in each closed loop represent the heatsmall
270 m/s

遷移層高さ
コロナ温度
フレア加熱
フレア範囲
フレア時間
熱伝導強度
冷却強度
冷却基準温度
冷却臨界密度
光球温度
光球密度
光球圧力スケール長
光球音速
光球音波横断時間
光球重力
熱伝導時間
冷却時間30123 × 10−11109wf
τf
κ0
Λ0CS0
τ0 ≡ H0 /CS0g05/2

τκ ∝ ρ0 H2 /(κ0 T0τΛ ∝ Tcl /(ρ0 Λ0 ))3 × 1010
2 × 10−86000 km240 s
10−6 cgs
8 × 10−22 erg s−1 cm3

FIG. 1.ÈSchematic pictures of the CSHKP-type recon

26Mm	  彩層蒸発計算（CANS-­‐1DHD）	

開始から２０秒後	
Density	
Velocity	
コロナ温度の鉄もまだ平衡でない	
FeXII	

まだFeXXIもまだ平衡でない	
FeXXI	FeXV	まだFeXXIVはできていない	FeXXVI	鉄イオン別の上下フラックス	
初期条件：電離平衡	

Upward	

点線：電離平衡	  Downward	
実線：電離非平衡	  FeXII	  Blue	FeXII	  Red	FeXV	  Blue	FeXV	  Red	FeXXI	  Blue	FeXXI	  Red	FeXXIV	  Blue	FeXXIV	  Red	

開始から17秒後	
Upward	Downward	
FeXII	  Red	FeXII	  Blue	FeXVで下降流が出ている	  上昇流も。。。	
FeXV	  Blue	FeXV	  Red	FeXXI	  Blue	FeXXI	  Red	FeXXIVはまだ光らない。。。	

FeXXIV	  Blue	FeXXIV	  Red	

まとめと今後の展望	• 電離非平衡＋彩層蒸発（１DHD）の計算は可能になった	  • 近年のEISの分光観測によってFeXV等でimpulsive	  phaseに〜５０km/sec程度の下降流が観測されている	  • 電離非平衡計算＋流体計算によって再現を試みた結果、FeXVで下降流を作る事は可能たが、定量的には説明困難	  • 熱伝導速度飽和やエネルギーインプットの仕方の違い等の可能性も考える必要が	  • Solar-­‐Cに向けて、Forwardモデリングを完成させ、フレアでのエネルギー解放を議論できるように