1

天の川銀河中心領域のＸ線観測
Ｘ線トモグラフィによるSgr A*の活動（1000年の活動）
GC South/North プラズマ（10万年の活動）
高階電離鉄輝線の起源（100万年？の活動）
銀河面の中性鉄輝線の起源

鶴 剛 (Kyoto University)
on behalf of the Suzaku GC team.
20141003_GC_Suzaku_CTA_v2.key2

1000年間の活動〜Ｘ線反射星雲の3-D配置〜

Ryu et al. 2009, PASJ, 61, 751
Ryu et al. 2013, PASJ, 65, 33
Ryu FY2012 Doctor Thesis, Kyoto Univ.

Observation of the GC region with Suzaku

1deg

204pointings, 5.96Msec
SWG, AO, LP, KP x2 (|l|<3.5°, |b|<5°)

3

R: 0.5-2.0keV
G: 2.0-5.0keV
B: 5.0-8.0keV

36 refereed papers,
7 Doctor Theses.

40.1

He-like S Kα
(2.45-keV line)

Neutral Fe Kα(6.4-keV line)

1deg

Narrow Line

0.01

−1Counts s keV−1

1

Suzaku Spectrum of the GC region

Mapping

1He-like Fe Kα(6.7-keV line)

25Energy (keV)106.7-keV Line Image (He-like Fe Kα)56.7keV (Continuum subtracted)

CHAPTER 2. REVIEWSgr A*

Photons cm-2 s-1 arcmin-21010(a)-5•
6.7-keVFe XXV K-610-810-9•GC

10-7

GRr〜500ly-

F=10×exp(–l/0.6deg) + exp(–l/50deg)

0.01

0.1

1

10

S XV K(b)ThermalPlasmas
10-5
smoothly
distribute in-6
10
the GC region.
-7
10The origin is still underdebate.
-8
10
Truly
diffuse plasma-910filling in the GC region.
Or, collectionof faint 1
0.01
0.1
*
unresolved
point
Distancefrom Sgr A along thsources.

Photons cm-2 s-1 arcmin-2

100ly

100

*

Distance from Sgralong
theSgrlongitudel* A(deg,fromA*) |l* | (degree)

Uchiyama+11, +12-counts/sec/ke

10 3

6X-ray Reflection Nebula

HAPTER 2. REVIEW

10 42020.01

Sgr(a) B2
Sgr B2
Koyama+07

5(b) M359.47 0.15

• Equivalent Width : 1–2keV• K-edge : N = 2–10 x 10 cm
Time: region after subtra
ig. 2.20.—: X-ray spectra of giant
MCs Variablein the GC•
pectrum of Sgr B2 (Koyama et al., 2007b). (b) spectrum of M 359.43−0
counts/sec/keV

Fig. 5.

6.4-keV line

10−0.07 (a) an23H310 4Energy-2

Size ~10 lys, τ ~ 10 yrst al., 2009). TheDeep
spectralfeatures
suggest the X-ray origin (see text).
absorptionedge
46(keV)(a) Sgr B2=−

Fig. 5.
Inui+09, Nobukawa+11
1995

2000

Ionizing particle is X-ray“X-rayReflection Nebula(XRN)”
0~~
σ=±(b)Sgr A, G 0.1–0.1(c)2
Need a source.
± .
×
39ergs/s
510with LX ~ 10
Energy (keV) = ==No such bright source.
−0.07 (a) andM 359.47−0.15(b).
Sgr A* is onlypossible
source.
. ± . one×2

2005 (year)

•••

−−−−

2−−−~−−:ı:ıEcho of the past activity of Sgr A*J =l b =7Long Term Light Curve of Sgr A*dXRN
isecho.

Collecting the data of XRNe
allows us to obtain past activityof Sgr A* reaching ~1000yr.

Face on(Top View)

Sgr A*Very Unique Study

Only Sgr A* allows us to access sucha long-term activity of a SMBH.

• L (Sgr A*) L (XRN) x Mass(XRN) x d^2 The line of sight• Distance “d” between XRN and Sgr A* position of XRN isX

X→ Look back time.

necessary.

8“X-ray Tomography”• The GC thermal plasma
distributes smoothly.

• If an XRN (MC) is located in thenear side of the thermal plasma,then soft X-rays from the plasma
is absorbed by the XRN due tophoto-absorption.

• In the case that the XRN (MC) islocated in the far side of thethermal plasma, soft X-rays fromthe plasma is un-absorbed.

Absorbed

XRN

GC –XRN

Near
ObserverThermal PlasmaMC) is located in the GC thermalplasma.

Thermal Plasma• An XRN (e.g. Molecular Cloud:FarCosmic X-ray Tomography

6.4-keV(XRN) XRN

Far100 ly

2.45-keV(Plasma)
StronglyAbsorbed
100 ly100光年

Absorbed

Sgr A*XRN

GC –XRN
Sgr C

Thermal Plasma

6.7-keV(Plasma)

Thermal Plasma

Sgr B2100 ly

9

Sgr A*XRN

NearA*
超巨大BH
Observer SgrQuantitative studies allow us to obtainthe line of sight potions of the XRNe.

LessAbsorbed

10Spectral Modeling
X-ray spectrum as a function of theline of sight position of XRN.

Cnt/s/keV

FeXXV
6.7 keV– 0.9
XRN

Plasma Emission→Spectral ModelContinuum of0.1Plasma Emission

FeI 6.4 keV

1.0 Far

– 0.8
– 0.7

XRN

– 0.6

RXRN

0.01

XRN

Decrease

13Energy (keV)

5Observer– 0.5 Center
– 0.4
– 0.3
– 0.2
– 0.1
0.0 Near
Ryu+09,	  +13

113-D distribution of XRNe
Edge-­‐on	  view

Face-­‐on	  view

far

near
Ryu+0.9, +13

12Light curve of Sgr A* in the past
Ryu+0.9, +13

With 90% errors

time variability

LX

Sgr A* is very quiet at present.
← PastTime (year)

Current• Sgr A* had been in active phase 50 - 600 years ago.
• Sgr A* made nearly one order of magnitude variation in ashort time (<10 years) at a couple of times.

How about before 600 yrs ago ?

13GC South Plasma : 10万年前の活動〜再結合プラズマの発見〜
Nakashima et al. 2013, ApJ, 773, 20
Nakashima FY2013 Doctor Thesis, Kyoto Univ.

Bipolar X-ray emission from the GC• M = 710M

1.0 1-3 keVのX線
中性鉄輝線
5-8 keVのX線@

E = 1.6x1051ergs

GC north0.5

n=0.16cm-3• 10~100個分のSNRに相当• 星団は無い．

Sgr A*0.0

X線反射星雲-1.0

SNRやSuper Bubbleではない1E 1740.7-2942

200pc

銀緯 (度)

GCDX-0.5

GC south-1.51.0

140.50.0

銀経 (度)-0.5-1.0

−1−1s−1 keVχCounts s−1 keVχCountsCountss−1 kχ(a)100−110−2−10(a)0−210−510−1

Recombining plasma model
Missing Fe L-shell complex
Background 2

0−5Fe-L
χ2/d.o.f = 2617/352
1378/350

BGD

GC south
Fe-L

Fe-L

Si XIV Si-RRC

イオン化平衡モデル
Fe-L

Fe-L

1

Si XIV Si-RRC

2Energy (keV)

S
再結合

S-RRC(b)(c)
(d)

(d)
(c)

RRC

χ /d.o.f = 2617/352

Fe-L(b)5 (c)0−210−550−515– 15 –Recombining
Plasma101010 (b)55χ

Recombining plasma model
Missing Fe L-shell complex
Backgroundχ22/d.o.f = 1378/350
2617/352
599/348

S-RRC
599/34810
5 χ2/d.o.f = 1378/350

Si entire
XIV Si-RRC
S-RRC
Fig. 4.— (a) Spectrum extracted from thesource region.
Only the co-added FI spectra
2(d)
125
χ
/d.o.f= 599/34810
and models
aredisplayedforvisibility,
thoughtheFIandBIspectra
weresimultaneously
5S
衝突励起• 強い再結合連続線(RRC)• 電離非平衡：イオン化温度 ＞ 電子温度（kTe=0.46keV）• イオン化温度：初期 kT =1.63keV & 0.16cm ~1×10 yr経過
Energy (keV)χfitted. 0The red, purple, and gray solid lines indicate the best-fit RP model, missing Fe L-

2−5shelllines,
andbackgroundmodel,respectively.
Theχ
values Only
fittedthewitheach of FI
thespectra
modelFig. 4.— (a) Spectrum extracted from the entire source region.
co-added
3init
are also
shown:(b) the1 CIE
model,
theFICIE
andFe-L shell
2 (c)the5 additional
10andmodels
are displayedfor plasma
visibility,
thoughandplasmaBI spectra
were simultaneously

5イオン化温度 > 電子温度 : ２つのシナリオ

16• 平衡状態から電子温度を下げる• 10 -10 yr前に爆発的星生成活動あり (Matsunaga+11,Yusef-Zadeh+09)• 超新星爆発 銀河中心領域で高温プラズマ• 銀河面垂直に吹き出す• 断熱膨張によりkTeが下がった．
• 音速で膨張に必要な時間 ~ 8x10 yr ← 観測と無矛盾• 平衡状態からイオン化温度を上げる• 元々低温のプラズマが存在していた• Sgr A*からのＸ線による光電離が起こる．L ~ 7.6x10 ergs/s• GC Plasma には，光電離 (RP)の痕跡がない．
574X

Sgr A*からのＸ線放射はビーミングか？

43

高階電離鉄輝線の起源：100万年？の活動〜点源寄せ集め or 真に拡がる？〜
Uchiyama et al. (2011) PASJ 63, S903
Uchiyama FY2009 Doctor Thesis, Kyoto Univ.

Global Distribution of Fe Kα Lines in the Galactic Center Region

6.7keV Line Profile vs Stellar and Point Sources Distribution(b)

Observed photons cm-s s-1 arcmin-2

10-5

6.7keV (at b =0.0)
This work
Koyama+07
Yamauchi+09

*

10-6

10-7

10-8
0.01

Stellar
Distribution

10-5Observed photons cm-s s-1 arcmin-2a)

10-6

6.7keV

10-7

Distribution of Point
source flux (4.8-8 keV)
10-8

0.1
110Distance from Sgr A* along the longitude |l*| (degree)

Sgr A*

0.1
1
Distance from Sgr A* along the latitude |b*| (degree)

Nobukawa, Hyodo+

Uchiyama+11 (d))

6.7keV Lines ExcessThisat
workGC
Koyama+07
Yamauchi+09-6

10

The 6.7keV has more
extended distribution
than point sources.
1010-5hotons cm-s s-1 arcmin-2

hotons cm-s s-1 arcmin-2

10-5

-6

Truly diffuse plasmaプラズマはエスケープしているか?

•• τ = 2×10 yr• エスケープエネルギー
Egas ~ 3×1052ergs
esc

4~0.70°~0.36°~ 10-3 SN yr -1•R: 6.7keV, G:2.45keV, B: 6.4keV
加熱 = 超新星爆発，Sgr A* の活動 ~10-5 SN yr-1
Tsuru+(Suzaku2007)
音速で逃げ出すと加熱が追いつかない
エスケープしていない．
磁場で閉じ込めか？

• B=0.1mG~1mG

PB/k =106-108 K/cm3 ~ Pgas/k =2×107 K/cm3
可能性あり

だが磁場に沿った方向にプラズマは移動できるのでは？

%$

**"*.

Ks polarization map 32 (P/P  2)UPU[S-

0.5%

VP
WUS-
磁場は銀河面に平行→閉じ込められる可能性あり
Nishiyama+13, ApJL, 769, 28

銀河面の中性鉄輝線(6.4keV)の起源

H.Uchiyama (Shizuoka), K.K.Nobukawa
T.Tsuru et al. (2014) arXiv:1408.0205v1

6.4-keV line emission from Ridge

22

1.00

EW map of the 6.4-keV line near GC
No region with such high EW has been discovered except the GC.
BAEC

0.000

Sgr D000

0.000

359.000

357.000

Ridge-1.000

Suzaku found that 6.4-keV line emission
with nearly equal EW uniformly exist.

extends toward
the Galactic ridge.

-2.000Key Question.
What is the origin of this 6.4-keV lineemission in the Galactic ridge ?

23Suzaku KeyProject (PI=Tsuru)

Suzaku Key Projectb (deg)-1.0

Clump2

4.0

3.0

2.0

1.00.0GC EastSuzaku
6-7 keV band image

East side of GC in l ~ 2° to 4°• Oct. 2012–Mar. 2014
• 100 ksec × 10 pointngs

1.0-2.0-3.0-4.0

GC Westl (deg)-1.0West side of GC in l ~ –2° to –4°• Oct. 2006–Feb. 2009
• 50 ksec × 12 pointngs

ï1 cmï2 arcminï2phsph sï1 cmï2 arcminï2
10ï8 10ï710ï7 10ï610ï6

Fe Iα (ph s cm arcmin )10−6GC East

GC West6.7-keV

10−710−86.4-keV

20−2−42 40 2
ï2 0ï4 ï2
Galactic Longtitude (degree) FeXXVKa-FeIKa_Int_OnGalplane.pdf
Galactic Longtitude
Galactic(degree)
Longtitude (degree)
6.4-keV : Asymmetry
6.7-keV : Symmetry

10ï84

6.4-keV 6.7-keV lines vs l

244

Origins of4 6.4-keV and2 6.7-keV are0 different.
ï2

10−710−7
10−7

10−810−8
4GC EastGC Westfootpoint
6.4-keV

13CO, NANTEN
Takeuchi+10
4 24
2 02
0 −2−2 −40−2
GalacticLongtitude(degree)
Galactic Longtitude(degree)
GalacticLongtitude(degree)

13CO Intensity
km s−1)(K km s−1
CO(KIntensity10−66.4-keV line flux & 13CO vs l103
103102102

10−4 −413−1−2 s−1 cm−2−2arcmin−2)
FeIα(phFe Iα (ph s cm arcmin )Fe Iα (ph s cm arcmin )10−610−625−8106.4-keV line
10 −4426.4-keV line
0 : Diffuse−2Origin
4 follows 2CO.
0−2−4FluorescencefromCool
Galactic Longtitude (degree) Matter.
Galactic Longtitude (degree)

26

Excess Spectrum (the 6.4-keV component)=• 中性Fe輝線の成分
Excess Spectrum in Easts keVarcmin
 CountsCountsskeVarcmin

ExcessSpectrumin East東(中性Feが強い)− 西(中性Feが弱い)

1.5!10

1.5!10
10Model: Power-law + Gaussian (6.4 keV)
Model:Gaussian
Large Power-law
excess in+6.4keV!! (6.4 keV)

East–West
East–West

Large
excess in 6.4 keV!!
component
value


10
5!10

5!10
0

0

0


0



!
ycomponent
6.4 keVnormalization

value×10−8(2.5±0.6)

6.4 keV normalization
Γ−8(2.5±0.6)
×10+0.9
3.1 −0.8

Γ
PL normalization

3.1+0.9−0.8(1.3±0.1)
×10−4

PL keVnormalization
6.4equivalent
widthequivalent(keV)
6.4 keV(1.3±0.1) ×10−4
1.3±0.4

1.3±0.4
2
rwidth(keV)
reduced χ (d.o.f.) = 1.21 (8)Energy (keV)a510ni
2 (d.o.f.) = 1.21 (8)reducedχ
Energy (keV)• This result depends
onthespectral
subtraction(EAST–WEST)
mi
等価幅大きい！
le in continuum• This=> Uncertainty
result depends
on the spectral subtraction (EAST–WEST)
rP=> Uncertainty
continuum• Plasma(6.7 keVinline)
distribution has large gradient on the Galactic Plane.
510• Plasma<=> The(6.7EastkeVandline)West
distribution
regions are
hasnotlarge
completelygradientsymmetric.
on the Galactic Plane.

27

Ionizing particles

proton origin
101100sys. err
this work

stat. err

electron origin
10–1–4

ung radiation

–3

–2
–1
photon index (Γ)

0Fig. 2. Equivalent width of the K˛ line for the solar abundance

ycross-sections
from Sgr A* produced
shouldbe radiatedisotropically.
by electrons(thick solid line)
and protons (thin solid line
for injection energy Einj = 80 MeV, dashed line for injection energy
proton (thinbrightEinj =density
50 MeV) as a should
function of thebe
spectralindex, #in. 6.4 keV.
=mp )Ep forwith highelump2#'!"&50

2.500

2.000

1.500

100

Fig. 1. Cross section of electron and proton bremat the energy 6.4 keV, d!br =dEX (dashed line), an!K of K˛ production for electron (thick solid lin
solid line). Here, E 0 = Ee for electrons and E 0
protons. Also, !K equals 0.3 and " is taken to be tfor this figure was kindly sent to us by Vincent Tat!"&clump2 footpoint$'!"%Dogiel et al. (2011)

Downloaded from http://pasj.oxf

6.4 keV EW (keV)

537

3.000footpoint()*+,-.+/01-02314+567+89#+2!+:;8930#<

Line from Sgr B2 by Subrelativistic Protons

h3.5000igin MeV陽子
of 6.4 keV line?
102

4.000#'!"%4.500!"%• Ｘ線光電離 or keV電子 or MeV陽子 ?
• 大きなEW 電子は除外• Sgr A* による光電離は等方的だろう• Clump2 / footpoint は非等方を示唆

Extremely large equivalent wi=> Electron origin is excluded
X-rays from Sgr A*?
Cosmic rayClump2
proton?

!""

X=is also generated by different processes:
in the collisional scenario and by Thomso
photoionization scenario.
The cross-sections ofclump2
bremsstrahlung andsubrelativistic protons and electrons are shoP
As one can see from the figure, the cproton
the energy#""bremsstrahlung$"" with!"""#"""Epcompletely
the same as for electrons with!#=>+/01-02314+5?+,9@2<protons, as shown in figure 1 by the dash
the cross-section !K of K˛ lines producedsolid line) and by protons (thin solid line)
If for electrons the cross-section ! of the i

最終的には，陽子起源をAstro-H カロリメーターで検証P28

CTAへの示唆• Sge A*のフレア活動• GCの巨大分子雲• Ｘ線の時間変動

Aharonian+ Nature06

Sgr A*の活動時間変化
TeVに時間変動は無い?

Figure 1 | VHE g-ray images of the Galactic Centre region. a, g-ray countmap; b, the same map after subtraction of the two dominant point sources,
showing an extended band of gamma-ray emission. Axes are Galactic
latitude (x) and Galactic longitude (y), units are degrees. The colour scale isin ‘events’ and is dimensionless. White contour lines indicate the density ofmolecular gas, traced by its CS emission. The position and size of thecomposite supernova remnant G0.9þ0.1 is shown with a yellow circle. Theposition of Sgr A* is marked with a black star. The 95% confidence region forthe positions of the two unidentified EGRETsources in the region are shown
as dashed green ellipses20. These smoothed and acceptance-corrected images
are derived from 55 hours of data consisting of dedicated observations of SgrA*, G0.9þ0.1 and a part of the data of the HESS Galactic plane survey21. Theexcess observed along the Galactic plane consists of ,3,500 g-ray photons
and has a statistical significance of 14.6 standard deviations. The absence ofany residual emission at the position of the point-like g-ray source G0.9þ0.1
demonstrates the validity of the subtraction technique. The energy
threshold of the maps is 380 GeV, owing to the tight g-ray selection cuts
applied here to improve signal/noise and angular resolution. We note that• 銀河面放射• Ｘ線はMeV陽子 TeVはTeV陽子• MeV陽子は大きく拡がれない 加速源を見ている？
• 加速源と伝搬

Thank you.