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

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

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) (with ID objects) – HESS J1825-137 (PWN) • Summary 2/32

TeV unidentified objects TeV Galactic Plane Survey HESS J1825-137 First example: (Aharonian et al. 2005, 2006) TeVJ2032+4130 discovered by HEGRA (Aharonian et al. 2002) Many have been HESS J1804-216 Gal. Cent. discovered in the Galactic Plane with H.E.S.S. •Spatially extended HESS J1616-508 •No counterpart. Dark particle accelerators HESS J1713-381 HESS J1614-518 3/32

Implications TeV gamma-rays � High-energy particles! What particles are accelerated, protons or electrons? If electrons, X-ray TeV E 2 f(E) X-ray … synchrotron Electron TeV … Inverse Compton of CMB Synch IC origin Flux(TeV)/F(X) =U(CMB)/U(B) ~1 with a few micro Gauss Energy Electrons emit synchrotron E 2 f(E) X-rays very easily! Proton π 0 origin Flux ratio (F(TeV)/F(X)) is a key to clarify the particles. 4/32 Energy

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

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. 6/32

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

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

XIS image of HESS J1614 XIS FI (S0+S2+S3): 3-10keV band Obs. 50ks TeVγ-ray Src A Src B Swift XRT also detected Extended object 9/32 (Landi et al. 2006)

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

Plausible X-ray counterpart: src A B=10 μ G HESS J1614 Src A Src B B=1 μ G src A B=0.1 μ G 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. 11/32 Matsumoto et al. 2008, PASJ, 60. S163 (Suzaku special issue No.2)

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

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/cm 2 13/32

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

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 Landi et al. 2007 has detected the PWN. Why is there no X-rays bridging the pulsar 15/32 and HESSJ1616?

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) Aharonian et al. (2005) No extended X-ray emission has been found before Suzaku. 16/32

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

X-ray spectrum of the sources Murakami et al., in preparation Both sources show power-law spectra. src1 src2 Point sources Point sources (Chandra) (Chandra) 5 1 2 10 2 5 1 10 Energy (keV) Energy (keV) Γ N H F X F(TeV)/F(X; src1 or src2) (10 -13 erg s -1 cm -2 ) (10 22 cm -2 ) = 10 � proton acceleration in Src 1 0.7 2.1 2.0 TeV J2032? Src 2 0.5 1.8 2.0 18/32

HESSJ1804-216 HESS TeV γ-ray image (excess map) Softest TeV spectrum among XIS FOV the new objects. 40ks HESSJ1804 (l, b)=(8.401, -0.033) Provided by S. Funk (MPI) 19/32

XIS image of HESS J1804 XIS FI (S0+S2+S3): 3-10keV Swift XRT (Landi et al. 2006) TeV image Chandra (Kargaltsev et al. 2007) src2 src1 Src1: point src Src2: extended Chandra (Kargaltsev et al. 2007) (Bamba et al. 2007) 40ks 20/32

XIS spectra HESSJ1804 src2 src2: extended src1 src1 src2 Γ -0.3±0.5 1.7±1.2 src1: point-like NH 0.2(<2.2) 11±8 (10 22 cm -2 ) F(2-10keV) 2.5 4.3 10 -13 erg/s/cm 2 F(TeV)/F(X) 50 25 See Bamba et al. 2007, PASJ, 59, S209 21/32 (Suzaku Special Issue No.1)

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

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) reg1 Blue: radio White: X-ray (Suzaku) Reg1: coincides with the TeV peak reg2 Reg2: offset hard emission 23/32

Suzaku 3.0-10.0 keV reg1 reg2 •Diffuse thermal gas + point source HESSJ1713 •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 24/32

HESS J 1825-137 • Spin-down luminosity ~ 2.8 × 10 36 erg s -1 • Characteristic age HESS J1825-137 21.4 kyr (Clifton 1992) H.E.S.S TeV γ excess map • D~4kpc Photon Index Γ PSR J1826-1334 30arcmin~30pc @4kpc softening Aharonian et al. 2006 Distance from Pulsar (deg) IC by high-energy electrons from the pulsar? 25/32

Previous X-ray study (XMM-Newton) PSR J1826-1334 (B1823-13) XMM-Newton Pulsar 0.5-10keV PWN H.E.S.S TeV γ excess map 1arcmin~1pc@4kpc Why is the X-ray image Gaensler et al. 2003 much smaller? Photon index ~ 2.3 More extended if observed with NH~1.4 × 10 22 /cm 2 high sensitivity? L X ~3 × 10 33 erg s -1 26/32 � Suzaku observation!

Suzaku: Very extended PWN TeV image HESSJ1825 XIS 3F 1-9 keV bgd 6arcmin ~6pc@4kpc source 2006/9 50ksec Suzaku can detect X-rays much more extended than the XMM results. 27/32 Uchiyama, H. et al., PASJ, 2009, in print

X-Ray Radial profile HESSJ1825 Source Background 1.2 × (CXB+GRXE) CXB+GRXE Galactic Ridge Unresolved X-ray Emission Point sources CXB X-rays are extended at least up to 15 arcmin (~17 pc) 28/32

A X-ray spectra B Region B C Region A =pulsar+PWN D Γ =1.99(1.91-2.08) Γ =1.78(1.68-1.88) HESSJ1825 Region C Region D Γ =2.03 (1.95-2.14) Γ =2.03 (1.95-2.14) Reg B-D: no change in photon index. � electrons reach to 17 pc before cooled . 29/32 Synchrotron cooling time~1900yrs. � Velectron>9000 km/s

Suzaku Results X-ray F(TeV)/F(X) Origin HESS J1614-518 extended 34 ? HESS J1616-508 X >55 PWN? TeV J2032+4130 2 extended 10 ? HESS J1804-216 2 objects 50 and 25 ? HESS J1713-381 O 0.2 SNR CTB37B efficient acceleration HESS J1825-137 Very extended 1.2 PWN 30/32

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? Not clarified! Still mystery! We need more information from radio to TeV gamma-rays 31/32

Summary • Suzaku results: F(TeV)/F(X) is very large. – Suggesting proton accleration. • X-ray: synchrotron from electrons. • TeV : proton + proton � π 0 � TeV gamma-rays • Origin is still not clarified. – Old SNR? – GRB remnant? – PWN? – Other object? 32/32