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X-ray Observations of the Dark Particle Accelerators

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

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X-ray Observations of the Dark Particle Accelerators

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

  2. 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. TeV unidentified objects HESS J1616-508 HESS J1614-518 HESS J1825-137 TeV Galactic Plane Survey (Aharonian et al. 2005, 2006) First example: TeVJ2032+4130 discovered by HEGRA (Aharonian et al. 2002) Many have been discovered in the Galactic Plane with H.E.S.S. HESS J1804-216 Gal. Cent. • Spatially extended • No counterpart. Dark particle accelerators HESS J1713-381

  4. Implications TeV gamma-rays  High-energy particles! What particles are accelerated, protons or electrons? If electrons, X-ray … synchrotron TeV … Inverse Compton of CMB X-ray TeV E2f(E) Electron origin Synch IC Flux(TeV)/F(X) =U(CMB)/U(B) ~1 with a few micro Gauss Energy Electrons emit synchrotron X-rays very easily! E2f(E) Proton origin π0 Flux ratio (F(TeV)/F(X)) is a key to clarify the particles. Energy

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

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

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

  9. XIS imageof HESS J1614 Swift XRT also detected (Landi et al. 2006) XIS FI (S0+S2+S3): 3-10keV band Obs. 50ks TeVγ-ray Src A Src B Extended object

  10. XIS spectra Src A spectrum HESS J1614 Src A NH=1.2(±0.5)e22cm-2 Γ=1.7(±0.3） F(2-10keV)=5e-13erg/s/cm2 Src B Src B spectrum • Featureless • non-thermal NH=1.2(±0.1)e22cm-2 Γ=3.6(±0.2） F(2-10keV)=3e-13erg/s/cm2 Featureless, but extremely soft

  11. Plausible X-ray counterpart: src A B=10μG HESS J1614 Src A Src B B=1μG src A B=0.1μG Src A F(1-10TeV)/F(2-10keV)=34 • Difficult to explain both the TeV gamma-ray and X-ray from the electron origin. • The origin of srcA is not clarified. Matsumoto et al. 2008, PASJ, 60. S163 (Suzaku special issue No.2)

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

  13. XIS image of HESS J1616 XIS FI (S0+S2+S3): 3—12keV TeV image F(TeV)/F(X)>55 45ks • No X-ray counterpart • F(2-10keV)<3.1e-13 erg/s/cm2

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

  15. PWN of PSRJ1617-5055? INTEGRAL 18-60keV XMM-Newton 0.5-10keV PSRJ1617 PSRJ1617 SNR RCW103 Neither radio (Kaspi et al. 1998) nor X-ray has detected the PWN. Why is there no X-rays bridging the pulsar and HESSJ1616? Landi et al. 2007

  16. TeV J2032+4130 HEGRA TeV gamma-ray image • 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. Aharonian et al. (2005)

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

  18. X-ray spectrum of the sources Murakami et al., in preparation Both sources show power-law spectra. src1 src2 Point sources (Chandra) Point sources (Chandra) 5 1 2 10 2 5 1 10 Energy (keV) Energy (keV) F(TeV)/F(X; src1 or src2) = 10 proton acceleration in TeV J2032?

  19. HESSJ1804-216 HESS TeV γ-ray image (excess map) Softest TeV spectrum among the new objects. XIS FOV 40ks (l, b)=(8.401, -0.033) Provided by S. Funk (MPI) HESSJ1804

  20. XIS image of HESS J1804 Swift XRT (Landi et al. 2006) Chandra (Kargaltsev et al. 2007) src2 src1 XIS FI (S0+S2+S3): 3-10keV TeV image Src1: point src Src2: extended (Bamba et al. 2007) Chandra (Kargaltsev et al. 2007) 40ks

  21. XIS spectra HESSJ1804 src2 src2: extended src1 src1: point-like F(TeV)/F(X) 50 25 See Bamba et al. 2007, PASJ, 59,S209 (Suzaku Special Issue No.1)

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

  23. Non-thermal hard X-ray Suzaku 0.3-3.0keV Nakamura, R. et al. PASJ, 2009, in print reg1 reg2 Foreground src Suzaku 3.0-10.0keV Green: TeV (HESSJ1713) Blue: radio White: X-ray (Suzaku) reg1 Reg1: coincides with the TeV peak Reg2: offset hard emission reg2

  24. Suzaku 3.0-10.0 keV reg1 reg2 HESSJ1713 • 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

  25. HESS J1825-137 H.E.S.S TeV γ excess map PSR J1826-1334 30arcmin~30pc @4kpc Aharonian et al. 2006 • Spin-down luminosity • ~ 2.8×1036 erg s-1 • Characteristic age • 21.4 kyr (Clifton 1992) • D~4kpc HESS J 1825-137 Photon Index Γ softening Distance from Pulsar (deg) IC by high-energy electrons from the pulsar?

  26. Previous X-ray study (XMM-Newton) PSR J1826-1334 (B1823-13) XMM-Newton 0.5-10keV Pulsar PWN H.E.S.S TeV γ excess map 1arcmin~1pc@4kpc Why is the X-ray image much smaller? Gaensler et al. 2003 Photon index ~ 2.3 NH~1.4×1022/cm2 LX~3×1033 erg s-1 More extended if observed with high sensitivity?  Suzaku observation!

  27. XIS 3F 1-9 keV Suzaku: Very extended PWN TeV image HESSJ1825 bgd 6arcmin ~6pc@4kpc source 2006/9 50ksec Suzaku can detect X-rays much more extended than the XMM results. Uchiyama, H. et al., PASJ, 2009, in print

  28. X-Ray Radial profile HESSJ1825 Source Background 1.2× (CXB+GRXE) CXB+GRXE Galactic Ridge X-ray Emission Unresolved Point sources CXB X-rays are extended at least up to 15 arcmin (~17 pc)

  29. A B Region B Region A C D Γ=1.99(1.91-2.08) Γ=1.78(1.68-1.88) Region C Region D Γ=2.03 (1.95-2.14) Γ=2.03 (1.95-2.14) X-ray spectra =pulsar+PWN HESSJ1825 Reg B-D: no change in photon index.  electrons reach to 17 pc before cooled. Synchrotron cooling time~1900yrs.Velectron>9000 km/s

  30. Suzaku Results

  31. 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? Not clarified! Still mystery! We need more information from radio to TeV gamma-rays

  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?

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