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X-ray follow-ups of TeV unID sources using Suzaku

X-ray follow-ups of TeV unID sources using Suzaku. Aya, T. Bamba (ISAS/JAXA, Japan) R. Yamazaki, K. Kohri, H. Matsumoto, H. Yamaguchi, G. Pühlhofer, S. J. Wagner. 1.1. Origin of Cosmic rays. Who and how to accelerate cosmic rays up to knee ?

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X-ray follow-ups of TeV unID sources using Suzaku

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  1. X-ray follow-ups of TeV unID sources using Suzaku Aya, T. Bamba (ISAS/JAXA, Japan) R. Yamazaki, K. Kohri, H. Matsumoto, H. Yamaguchi, G. Pühlhofer, S. J. Wagner

  2. 1.1. Origin of Cosmic rays Who and how to accelerate cosmic rays up to knee ? diffusive shock acc. in shocks ? = biggest problem ! difficulties: rg ~ pc in interstellar B -> we cannot point out accelerators How to search for accelerators ? TeV electron IS B. (~mG) synchrotron X-rays Inverse Compt. (e) piondecay (p) TeV gamma-rays hard X-rays and TeV gamma-rays are the best for the accelerator search.

  3. 1.2. New Candidates: TeV unID sources A lot of sources are discovered from the GP They are not known PSRs, PWNe known SNRs known SF regions known EGRET source “TeV unID sources” “dark particle accelerators” (Aharonian+ 2006) X-ray follow-ups are needed !

  4. 1.3. X-ray follow-ups of TeV unIDs (1): known categories PWN !! HESS J1718-3825 XMM-Newton (Hinton+ 2007) HESS J1837-069 Chandra (Gotthelf+ 2008) HESS J1813-178 XMM-Newton (Funk+ 2007) (See also Pühlhofer’s invited talk, Uchiyama+ poster D12) SNR !! Many samples are PWN CTB37B Suzaku (Nakamura+ submitted)

  5. 1.4. X-ray follow-ups of TeV unIDs (2): unknown categories Some source but unID !! No counterpart !! HESS J1614-518 Suzaku (Matsumoto+ 2008) HESS J1616-508 Suzaku (Matsumoto+ 2007) Compact unID sources !! Molecular cloud ?? HESS J1804-218: Suzaku (Bamba+ 2007) Galactic center region radio obs. (Aharonian+ 2006) Many kinds of TeV unIDs !

  6. 2.1. One of the most mysterious TeV unIDs : HESS J1745-303 • Discovered by H.E.S.S. (Aharonian+ 2005) • Near the Galactic Center • One of the most extended source (~0.5 deg) • Rather soft (Gamma=2.7) and bright (5.2x10-12ergs cm-2s-1) • No couterpart ! -> Suzaku is the best toolfor the counter part search: low and stable bgd 0.5 deg This one ! 50ks x 4 pointing mapping obs. color: TeV contour: molecular cloud

  7. 2.2. Suzaku image of HESS J1745-303 (1) No X-ray ! SNRs G359.0-0.9, G359.1-0.5 (Bamba+ 2000) ROSAT sources 0.5-2.0 keV (Suzaku) contour: HESS

  8. 2.3. Suzaku image of HESS J1745-303 (2) No X-ray ! 2.0-8.0 keV (Suzaku) contour: HESS

  9. 2.4. Suzaku image of HESS J1745-303 (3) 6.4 keV ion line (Suzaku) contour: HESS Some excess on HESS J1745-303 ??

  10. 3.1. Spectral Analysis (1) continuum comp. src Src: TeV peak region bgd: TeV free region bgd1 bgd2 Compare the flux (Assuming Gamma = 2.0) F2-10 keV < 2.1 x 10-13 ergs cm-2s-1 c.f. F1-10TeV = 5.2 x 10-12 ergs cm-2s-1 one of the mostX-ray faint TeV unIDs! F1-10TeV F2-10keV > 25

  11. 3.2. Spectral Analysis (2) neutral iron line src 6.4 keV flux density 6.7 keV flux density 6.4/6.7 (ph/cm2/s/arcmin2) (ph/cm2/s/arcmin2) src: 6.5e-8 ± 0.7e-8 1.1e-7 ± 0.08e-7 0.58 ± 0.03 bgd1: 5.9e-8 ± 2.2e-8 1.2e-7 ± 0.2e-7 0.49 ± 0.20 bgd1 Src region has stronger 6.4 keV line although the statistics is not enough … bgd2 6.7keV (He-like Fe) 6.4keV (neutral Fe) 5.9keV (MnKa: bgd) Src Ni Ka (bfd) total excess: 6.1x10-6 ph cm-2s-1 bgd1

  12. 4.1. Discussion 1: Nonthermal continuum emission F2-10 keV < 2.1 x 10-13 ergs cm-2s-1 F1-10TeV = 5.2 x 10-12 ergs cm-2s-1 different from known sources (SNR/PWN …) c.f. Crab: FTeV/FX ~3x10-3 RXJ1713: FTeV/FX ~ 0.06 The TeV gamma-ray emission from the GC MCs MC are faint in nonthermal X-rays HESS J1745 coinsides with MC (Aharonian+ 2008) HESS J1745 could emit TeV gamma-rays in the same way of the TeV GC emission F1-10TeV F2-10keV > 25 (Bitran+ 1997) (Aharonian+ 2008)

  13. 4.2. Discussion 2: neutral iron line neutral iron line near the GC, coinside with MC = reflection on the MC by the past bright GC (Koyama+ invited talk, Murakami+ 2001) Sgr B2 HESSJ1745 line Int. 5.6e-5 6.1e-6 MMC 6e6 Mo 5e4 Mo size 0.05 deg. 0.3 deg. d from GC 0.7 deg. 1.2 deg. line int. ~ mass x viewing angle ~ mass x (size)2 x (distance)-2 HESSJ1745: 7.0e-6 ph cm-2s-1 The neutral iron line can be explained by X-ray reflection of the past bright GC HESS J1745-303 – MC association in the GC region ! could be similar source to the TeV GC emission Cosmic rays make TeV emission with attacking MC ??? (Aharonian+ 2006) Where is the CR source ?? G359.1-0.5 ??

  14. 5. Summary • The origin of TeVunID sources are still unknown. • HESS J1745-303 is one of the most interesting source • near the Galactic center. • We made deep X-ray follow-ups of HESS J1745-303 • with Suzaku. • We made tight upper-limit in the X-ray band. • The excess of neutral iron line is found from the MC, • which could associate the TeVunID. • HESS J1745-303 could be TeV emission from a MC • with CR attacking like GC diffuse TeV emission. • In order to pinpoint the origin of this interesting source, • more follow-ups are needed in other wavelengths.

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