1. 1/32 X-ray Observations of the Dark Particle Accelerators Hironori Matsumoto (Kyoto Univ.)

2. 2/32 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)

3. 3/32 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.

4. 4/32 Implications What particles are accelerated, protons or electrons? Electrons emit synchrotron X-rays very easily! Electron origin E 2 f(E) Energy π0π0 X-rayTeV Proton origin 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!

5. 5/32 The Suzaku Satellite Hard X-ray Detector (HXD) X-ray Telescope (XRT) X-ray Imaging Spectrometer (XIS) +

6. 6/32 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.

7. 7/32 GC spectrum 6.4keV 6.7keV 6.9keV Clear iron lines XIS spectrum High-energy resolution & High sensitivity (Low BGD)

8. 8/32 HESSJ1614-518 (l, b)=(331.52, -0.58) HESS TeV γ-ray image (excess map) XIS FOV 50ks Brightest among the new objects. HESSJ1614

9. 9/32 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

10. 10/32 XIS spectra NH=1.2(±0.5)e22cm -2 Γ=1.7(±0.3 ） F(2-10keV)=5e-13erg/s/cm 2 NH=1.2(±0.1)e22cm -2 Γ=3.6(±0.2 ） F(2-10keV)=3e-13erg/s/cm 2 Featureless  non-thermal Featureless, but extremely soft Src A Src B Src A spectrum Src B spectrum HESS J1614

11. 11/32 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

12. 12/32 HESSJ1616-508 HESS TeV image (excess map) (l, b)=(332.391, -0.138) XIS FOV 45ks Provided by S. Funk (MPI) HESSJ1616

13. 13/32 XIS image of HESS J1616 XIS FI (S0+S2+S3): 3 — 12keV No X-ray counterpart F(2-10keV)<3.1e-13 erg/s/cm 2 TeV image 45ks F(TeV)/F(X)>55

14. 14/32 If we assume electrons… Very weak B (B<1μGauss) HESSJ1616 SED Suzaku upper limit Strong cut-off or realistic? Matsumoto et al. 2007, PASJ, 59, 199 (Suzaku Special Issue No.1)

15. 15/32 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

16. 16/32 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.

17. 17/32 Suzaku observation of TeV J2032 December 2007, 40ks obs. Two extended X-ray objects src1 src2 Murakami, H. et al., in preparation TeV region

18. 18/32 X-ray spectrum of the sources N H (10 22 cm -2 ) ΓF X (10 -13 erg s -1 cm -2 ) Src 10.72.12.0 Src 20.51.82.0 Both sources show power-law spectra. src1src2 Energy (keV) 12 5 10 52 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?

19. 19/32 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

20. 20/32 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)

21. 21/32 XIS spectra src1 src2 src1: point-like src2: extended src1src2 Γ-0.3±0.51.7±1.2 NH (10 22 cm -2 ) 0.2(<2.2)11±8 F(2-10keV) 10 -13 erg/s/cm 2 2.54.3 See Bamba et al. 2007, PASJ, 59, S209 (Suzaku Special Issue No.1) F(TeV)/F(X) 50 25 HESSJ1804

22. 22/32 HESSJ1713-381 (CTB37B) SNR CTB37B HESSJ1713-381 coincides with the SNR CTB37B Color: TeV White: radio

23. 23/32 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 reg2 Foreground src Reg1: coincides with the TeV peak Reg2: offset hard emission

24. 24/32 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

25. 25/32 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 ~ 2.8×10 36 erg s -1 Characteristic age 21.4 kyr (Clifton 1992) D~4kpc softening

26. 26/32 Previous X-ray study (XMM-Newton) PSR J1826-1334 (B1823-13) Photon index ~ 2.3 NH~1.4×10 22 /cm 2 L X ~3×10 33 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!

27. 27/32 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

28. 28/32 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

29. 29/32 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) 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

30. 30/32 Suzaku Results X-rayF(TeV)/F(X)Origin HESS J1614-518 extended34? HESS J1616-508 X>55PWN? TeV J2032+4130 2 extended10? HESS J1804-216 2 objects50 and 25? HESS J1713-381 O0.2SNR CTB37B efficient acceleration HESS J1825-137 Very extended1.2PWN

31. 31/32 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!

32. 32/32 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?