X-ray follow-ups of TeV unID sources

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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
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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
-gt we cannot point out accelerators
How to search for accelerators ?
TeV electron IS B. (mG)
synchrotron X-rays
Inverse Compt. (e) pion decay (p)
TeV gamma-rays
hard X-rays and TeV gamma-rays are the best for
the accelerator search.
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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 !
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1.3. X-ray follow-ups of TeV unIDs (1) known
categories
HESS J1718-3825 XMM-Newton (Hinton 2007)
HESS J1837-069 Chandra (Gotthelf 2008)
(See also Pühlhofers invited talk, Uchiyama
poster D12)
Many samples are PWN
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1.4. X-ray follow-ups of TeV unIDs (2) unknown
categories
Some source but unID !!
HESS J1614-518 Suzaku (Matsumoto 2008)
Compact unID sources !!
HESS J1804-218 Suzaku (Bamba 2007)
Many kinds of TeV unIDs !
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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 (Gamma2.7) and bright
  (5.2x10-12ergs cm-2s-1)
• No couterpart !

-gt Suzaku is the best tool for the counter part
search low and stable bgd
0.5 deg
50ks x 4 pointing mapping obs.
color TeV contour molecular cloud
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2.2. Suzaku image of HESS J1745-303 (1)
No X-ray !
0.5-2.0 keV (Suzaku) contour HESS
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2.3. Suzaku image of HESS J1745-303 (2)
No X-ray !
2.0-8.0 keV (Suzaku) contour HESS
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2.4. Suzaku image of HESS J1745-303 (3)
6.4 keV ion line (Suzaku) contour HESS
Some excess on HESS J1745-303 ??
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3.1. Spectral Analysis (1) continuum comp.
Src TeV peak region bgd TeV free region
Compare the flux (Assuming Gamma 2.0)
F2-10 keV lt 2.1 x 10-13 ergs cm-2s-1
c.f. F1-10 TeV 5.2 x 10-12 ergs cm-2s-1
one of the most X-ray faint TeV unIDs!
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3.2. Spectral Analysis (2) neutral iron line
Src region has stronger 6.4 keV line although
the statistics is not enough
total excess 6.1x10-6 ph cm-2s-1
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4.1. Discussion 1 Nonthermal continuum emission
F2-10 keV lt 2.1 x 10-13 ergs cm-2s-1
F1-10 TeV 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
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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)
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 ??
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5. Summary

• The origin of TeV unID 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 TeV unID.
• 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.