X-ray Observations of the Dark Particle Accelerators Hironori - - PowerPoint PPT Presentation

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X-ray Observations of the Dark Particle Accelerators

Hironori Matsumoto (Kyoto Univ.)

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Outline

• TeV unID objects: “Dark particle accelerators”
• The Suzaku satellite
• Suzaku Observations

– HESS J1614-518 – HESS J1616-508 – TeV J2032+4130 – HESS J1804-216 – HESS J1713-381 (SNR CTB37B) – HESS J1825-137 (PWN)

• Summary

(with ID objects)

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TeV unidentified objects

• Spatially extended
• No counterpart.

TeV Galactic Plane Survey (Aharonian et al. 2005, 2006) HESS J1804-216 HESS J1616-508 HESS J1614-518

• Gal. Cent.

HESS J1713-381

Dark particle accelerators

HESS J1825-137

First example: TeVJ2032+4130 discovered by HEGRA (Aharonian et al. 2002) Many have been discovered in the Galactic Plane with H.E.S.S.

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Implications

What particles are accelerated, protons or electrons?

Electrons emit synchrotron X-rays very easily!

Electron

• rigin

E2f(E) E2f(E) Energy Energy

π0

X-ray TeV Proton

• rigin

Synch IC

If electrons, X-ray … synchrotron TeV … Inverse Compton of CMB Flux(TeV)/F(X) =U(CMB)/U(B) ~1 with a few micro Gauss

Flux ratio (F(TeV)/F(X)) is a key to clarify the particles. TeV gamma-rays High-energy particles!

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The Suzaku Satellite

Hard X-ray Detector (HXD) X-ray Telescope (XRT) X-ray Imaging Spectrometer (XIS)

+

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Onboard Detectors

• X-ray Telescope (XRT) + X-ray Imaging Spectrometer (XIS)
• Mirror + CCD
• E=0.3—12keV
• Imaging & Spectroscopy
• High sensitivity (low background) & High-energy resolution
• Hard X-ray Detector (HXD)
• Semiconductor (PIN-Si) & scintillator (BGO&GSO)
• E=10—600keV
• High sensitivity (low background), though no imaging capability.

Suzaku is the best tool for studying dim and diffuse objects.

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GC spectrum

6.4keV 6.7keV 6.9keV

Clear iron lines

XIS spectrum High-energy resolution & High sensitivity (Low BGD)

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HESSJ1614-518

(l, b)=(331.52, -0.58)

HESS TeV γ-ray image (excess map)

XIS FOV 50ks Brightest among the new objects. HESSJ1614

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XIS FI (S0+S2+S3): 3-10keV band Extended object

TeVγ-ray

XIS image of HESS J1614

Swift XRT also detected (Landi et al. 2006)

• Obs. 50ks

Src A

Src B

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XIS spectra

NH=1.2(±0.5)e22cm-2 Γ=1.7(±0.3） F(2-10keV)=5e-13erg/s/cm2 NH=1.2(±0.1)e22cm-2 Γ=3.6(±0.2） F(2-10keV)=3e-13erg/s/cm2

• Featureless

non-thermal Featureless, but extremely soft

Src A Src B Src A spectrum Src B spectrum HESS J1614

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src A B=10μG B=1μG B=0.1μG

Src A Src B

Src A F(1-10TeV)/F(2-10keV)=34

Plausible X-ray counterpart: src A

Matsumoto et al. 2008, PASJ, 60. S163 (Suzaku special issue No.2)

• Difficult to explain both the TeV gamma-ray and X-ray from

the electron origin.

• The origin of srcA is not clarified.

HESS J1614

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HESSJ1616-508

HESS TeV image (excess map)

(l, b)=(332.391, -0.138) XIS FOV 45ks

Provided by S. Funk (MPI)

HESSJ1616

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XIS image of HESS J1616

XIS FI (S0+S2+S3): 3—12keV

• No X-ray counterpart
• F(2-10keV)<3.1e-13 erg/s/cm2

TeV image

45ks F(TeV)/F(X)>55

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If we assume electrons…

Very weak B (B<1μGauss)

HESSJ1616 SED Suzaku upper limit

Strong cut-off

• r

realistic?

Matsumoto et al. 2007, PASJ, 59, 199 (Suzaku Special Issue No.1)

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PWN of PSRJ1617-5055?

INTEGRAL 18-60keV

PSRJ1617

Landi et al. 2007

XMM-Newton 0.5-10keV PSRJ1617

Neither radio (Kaspi et al. 1998) nor X-ray has detected the PWN. Why is there no X-rays bridging the pulsar and HESSJ1616?

SNR RCW103

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TeV J2032+4130

HEGRA TeV gamma-ray image

Aharonian et al. (2005)

• First TeV unID object (in

2002, HEGRA).

• Cygnus region. Close to
• Cyg OB2 (OB stars)
• Cyg X-3 (micro-QSO)
• EGRET source
• Extended (~6arcmin)

No extended X-ray emission has been found before Suzaku.

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Suzaku observation of TeV J2032

December 2007, 40ks obs. Two extended X-ray objects

src1 src2 Murakami, H. et al., in preparation

TeV region

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X-ray spectrum of the sources

2.0 1.8 0.5 Src 2 2.0 2.1 0.7 Src 1 FX

(10-13 erg s-1 cm-2)

Γ NH

(1022 cm-2)

Both sources show power-law spectra. src1 src2

Energy (keV) Energy (keV) 1 2 5 10 10 5 2 1

Murakami et al., in preparation

Point sources (Chandra) Point sources (Chandra)

F(TeV)/F(X; src1 or src2) = 10 proton acceleration in TeV J2032?

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HESSJ1804-216

HESS TeV γ-ray image (excess map)

Provided by S. Funk (MPI)

(l, b)=(8.401, -0.033) XIS FOV 40ks Softest TeV spectrum among the new objects. HESSJ1804

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XIS image of HESS J1804

XIS FI (S0+S2+S3): 3-10keV src1 src2 Src1: point src Src2: extended (Bamba et al. 2007)

TeV image

40ks

Swift XRT (Landi et al. 2006) Chandra (Kargaltsev et al. 2007)

Chandra (Kargaltsev et al. 2007)

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XIS spectra

src1 src2 src1: point-like src2: extended

11±8 0.2(<2.2) NH (1022cm-2) 4.3 2.5 F(2-10keV) 10-13erg/s/cm2 1.7±1.2

• 0.3±0.5

Γ src2 src1

See Bamba et al. 2007, PASJ, 59, S209 (Suzaku Special Issue No.1)

F(TeV)/F(X) 50 25

HESSJ1804

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HESSJ1713-381 (CTB37B)

SNR CTB37B

HESSJ1713-381 coincides with the SNR CTB37B

Color: TeV White: radio

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Non-thermal hard X-ray

Nakamura, R. et al. PASJ, 2009, in print

Suzaku 0.3-3.0keV Suzaku 3.0-10.0keV

Green: TeV (HESSJ1713) Blue: radio White: X-ray (Suzaku) reg1 reg1 reg2 reg2 Foreground src

Reg1: coincides with the TeV peak Reg2: offset hard emission

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Suzaku 3.0-10.0 keV

reg1 reg2

• Diffuse thermal gas + point source
• Thermal (kT=0.9keV)+PL(Γ=3.0)
• PL: A point source discovered by Chandra

(Aharonian et al. 2008).

• Non-thermal X-ray Emission
• Hard PL (Γ=1.5) (+ Leakage from reg1).
• Roll-off (cut-off) energy > 15keV

Very efficient acceleration. F(TeV)/F(X)~0.2 B~8uG assuming IC. Emax > 170 TeV

HESSJ1713

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HESS J 1825-137

30arcmin~30pc @4kpc

HESS J1825-137

Aharonian et al. 2006 H.E.S.S TeV γ excess map PSR J1826-1334

Distance from Pulsar (deg) Photon Index Γ

IC by high-energy electrons from the pulsar?

• Spin-down luminosity

~ 2.8×1036 erg s-1

• Characteristic age

21.4 kyr (Clifton 1992)

• D~4kpc

softening

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Previous X-ray study (XMM-Newton)

PSR J1826-1334 (B1823-13) Photon index ~ 2.3 NH~1.4×1022/cm2 LX~3×1033 erg s-1 1arcmin~1pc@4kpc Pulsar

PWN

XMM-Newton 0.5-10keV

H.E.S.S TeV γ excess map

Gaensler et al. 2003 Why is the X-ray image much smaller? More extended if observed with high sensitivity? Suzaku observation!

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Suzaku: Very extended PWN

XIS 3F 1-9 keV

source

6arcmin ~6pc@4kpc 2006/9 50ksec

bgd

Suzaku can detect X-rays much more extended than the XMM results.

TeV image

Uchiyama, H. et al., PASJ, 2009, in print

HESSJ1825

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1.2× (CXB+GRXE)

CXB+GRXE

Galactic Ridge X-ray Emission

CXB

Background Source

X-Ray Radial profile

Unresolved Point sources X-rays are extended at least up to 15 arcmin (~17 pc)

HESSJ1825

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X-ray spectra

Region A Region B Region C Region D Γ=1.78(1.68-1.88) Γ=1.99(1.91-2.08) Γ=2.03 (1.95-2.14) Γ=2.03 (1.95-2.14) A B C D

Reg B-D: no change in photon index. electrons reach to 17 pc before cooled.

=pulsar+PWN Synchrotron cooling time~1900yrs.Velectron>9000 km/s

HESSJ1825

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Suzaku Results

? 50 and 25 2 objects

HESS J1804-216

PWN 1.2 Very extended

HESS J1825-137

SNR CTB37B efficient acceleration 0.2 O

HESS J1713-381

? 10 2 extended

TeV J2032+4130

PWN? >55 X

HESS J1616-508

? 34 extended

HESS J1614-518

Origin F(TeV)/F(X) X-ray

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What is the dark accelerators?

• Old SNR? (Yamazaki et al. 2006)
• Electrons lost their energy by synchrotron cooling.
• Protons still keep energy due to small cooling rate.
• There should be more unID objects.

(SN rate .. ~1SN/100yr ~100 unID objects?)

• GRB remnants or hyper-nova remnants? (Atoyan et al.

2006)

• GRB rate in our Galaxy may be consistent with the

number of unID objects.

• PWN?

We need more information from radio to TeV gamma-rays

Not clarified! Still mystery!

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Summary

• Suzaku results: F(TeV)/F(X) is very large.

– Suggesting proton accleration.

• X-ray: synchrotron from electrons.
• TeV : proton + proton π0 TeV gamma-rays
• Origin is still not clarified.

– Old SNR? – GRB remnant? – PWN? – Other object?