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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 J1713-381 (CTB37B) HESS J1804-216 HESS J1825-137

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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 J1713-381 (CTB37B) • HESS J1804-216 • HESS J1825-137 • HESS J1837-069 • Summary

  3. TeV unidentified objects HESS J1616-508 HESS J1614-518 HESS J1825-137 HESS J1837-069 TeV Galactic Plane Survey (Aharonian et al. 2005, 2006) Many new TeV objects with no obvious counterpart. HESS J1804-216 Gal. Cent. First example: TeVJ2032+4130 discovered by HEGRA (Aharonian et al. 2002) 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—10keV • 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) Suzaku is the best tool for studying dim and diffuse objects.

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

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

  9. XIS spectra Src A spectrum 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

  10. B=10μG H.E.S.S. B=1μG src A B=0.1μG Plausible X-ray counterpart: src A Src A Src B 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)

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

  12. XIS image 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

  13. 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)

  14. PSRJ1617-5055? INTEGRAL 18-60keV XMM-Newton 0.5-10keV PSRJ1617 PSRJ1617 SNR RCW103 Why is there no trace in X-ray band? Why is there no clear PWN in the radio (Kaspi et al. 1998) and X-ray bands? Landi et al. 2007

  15. TeV J2032+4130 HEGRA TeV gamma-ray image • First TeV unID object discovered with the HEGRA telescope. • Cygnus region. Close to • Cyg OB2 (OB stars) • Cyg X-3 (micro-QSO) • EGRET source • Extended (~6arcmin) Aharonian et al. (2005)

  16. Suzaku observation December 2007, 40ks obs. Two extended X-ray objects src2 src1 Murakami et al., in preparation

  17. 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 Suggesting proton acceleration.

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

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

  20. Suzaku 3.0-10.0 keV reg1 reg2 • Thermal (kT=0.9keV)+PL(Γ=3.0) • A point source discovered by Chandra (Aharonian et 1l. 2008) contributes much to the PL component. • Hard PL (Γ=1.5) (+ Leakage from reg1). • Roll-off energy > 15keV • The hard PL suggests efficient acceleration. F(TeV)/F(X)~0.2  B~8uG assuming IC. Emax > 170 TeV

  21. 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

  22. XIS image Swift XRT (Landi et al. 2006) Chandra (Kargaltsev et al. 2007) src2 src1 src1: point-like src2: extended or multiple XIS FI (S0+S2+S3): 3-10keV TeV image Chandra (Kargaltsev et al. 2007) 40ks

  23. XIS spectra 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)

  24. 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?

  25. 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!

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

  27. Radial profile 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)

  28. 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 Reg B-D: no change in photon index.  electrons reach to 17 pc before cooled. Synchrotron cooling time~1900yrs.Velectron>9000 km/s

  29. Suzaku Results

  30. 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! We need more information from radio to TeV gamma-rays

  31. 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 not still clarified. • Old SNR? • GRB remnant? • PWN? • Other object?

  32. HESSJ1837-069 INTEGRAL/ISGRI (Malizia et al. 2005) HESS image 1degx1deg X-rays were detected up to 300 keV by INTEGRAL

  33. Offset pulsar wind nebula Anada et al. in preparation AXJ1837.3-0652 TeV peak AXJ1838.0-0655 X-ray counterparts are offset from the TeV gamma-ray peak. Pulsations of 70.5 ms were recently discovered from AXJ1838 with RXTE (Gotthelf et. al. 2008).

  34. Summary

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