Suzaku Observations of HESS sources Hironori Matsumoto (Kyoto Univ.) Hideki Uchiyama (Kyoto Univ.), Aya Bamba, Ryoko Nakamura, Takayasu Anada (ISAS/JAXA), and the Suzaku team 1/25
Outline • HESS unID objects: “Dark particle accelerators” • Suzaku Observations – HESSJ1614-518 – HESSJ1616-508 – HESSJ1713-381 (CTB37B) – HESSJ1804-216 – HESSJ1825-137 – HESSJ1837-069 • Summary 2/25
HESS Galactic Plane Survey HESSJ1825-137 HESSJ1837-069 First systematic Galactic plane survey with TeV γ-ray (>200GeV) HESSJ1804-216 Gal. Cent. New TeV objects with no obvious counterpart. HESSJ1616-508 Dark particle accelerators HESSJ1713-381 HESSJ1614-518 3/25 (Aharonian et al. 2005, 2006)
HESSJ1614-518 HESS TeV γ-ray image (excess map) Brightest among XIS FOV the new objects. 50ks HESSJ1614 (l, b)=(331.52, -0.58) 4/25
XIS image XIS FI (S0+S2+S3): 3-10keV band Obs. 50ks TeVγ-ray Src A Src B Swift XRT also detected Extended object 5/25 (Landi et al. 2006)
XIS spectra Src A spectrum 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, 6/25 but extremely soft
Plausible X-ray counterpart: src A B=10 μ G Src A H.E.S.S. Src B B=1 μ G src A Src A B=0.1 μ G 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. 7/25 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) 8/25
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/cm 2 9/25
If we assume electrons… Very weak B (B<1μGauss) realistic? Suzaku upper limit or Strong cut-off HESSJ1616 SED 10/25 Matsumoto et al. 2007, PASJ, 59, 199 (Suzaku Special Issue No.1)
PSRJ1617-5055? INTEGRAL 18-60keV XMM-Newton 0.5-10keV PSRJ1617 PSRJ1617 SNR RCW103 Why is there no trace in X-ray band? Landi et al. 2007 Why is there no clear PWN in the radio (Kaspi et al. 1998) and X-ray bands? 11/25
HESSJ1713-381 (CTB37B) Color: TeV White: radio SNR CTB37B HESSJ1713-381 coincides with the SNR CTB37B 12/25
Non-thermal hard X-ray Suzaku 0.3-3.0keV Nakamura 2008 in preparation reg1 reg2 Foreground src Suzaku 3.0-10.0keV Green: TeV (HESS) reg1 Blue: radio White: X-ray (Suzaku) Reg1: coincides with the TeV peak reg2 Reg2: offset hard emission 13/25
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 due to PSF. •Roll-off energy > 15keV •The hard PL suggests efficient acceleration. F(TeV)/F(X)~0.2 � B~8uG assuming IC. Emax > 170 TeV 14/25
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) 15/25
XIS image XIS FI (S0+S2+S3): 3-10keV Swift XRT (Landi et al. 2006) TeV image Chandra (Kargaltsev et al. 2007) src2 src1 src1: point-like Chandra (Kargaltsev et al. 2007) src2: extended 40ks or multiple 16/25
XIS spectra 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 17/25 (Suzaku Special Issue No.1)
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? 18/25
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 19/25 � Suzaku observation!
Suzaku: Very extended PWN TeV image 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. 20/25
Radial profile 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 (~15 pc) 21/25
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) 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 15pc before cooled . 22/25 Synchrotron cooling time~1400yrs. � Velectron~10000 km/s
HESSJ1837-069 INTEGRAL/ISGRI (Malizia et al. 2005) HESS image 1degx1deg X-rays were detected up to 300 keV by INTEGRAL 23/25
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). 24/25
Summary X-ray Origin HESSJ1614-518 O ? HESSJ1616-508 X ? HESSJ1713-381 O SNR CTB37B Can you construct a “Grand Unification Theory (GUT)” Efficient acceleration of the dark particle accelerators? HESSJ1804-216 2 ? HESSJ1825-137 Very extended PWN HESSJ1837-069 2 extended Offset PWN 25/25
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