x-ray follow-ups of tev unid sources using suzaku aya, t. bamba (isas/jaxa, japan) r. yamazaki, k....
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X-ray follow-ups of TeV unID sourcesusing 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
TeV electron IS B. (~G)
synchrotron X-rays
Who and how to accelerate cosmic rays up to knee ?diffusive shock acc. in shocks ? = biggest problem !
How to search for accelerators ?
hard X-rays and TeV gamma-rays are the bestfor the accelerator search.
difficulties: rg ~ pc in interstellar B-> we cannot point out accelerators
Inverse Compt. (e)pion decay (p)
TeV gamma-rays
(Aharonian+ 2006)
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”
X-ray follow-ups are needed !
1.3. X-ray follow-ups of TeV unIDs (1): known categories
HESS J1813-178XMM-Newton(Funk+ 2007)
PWN !!
SNR !!
CTB37BSuzaku(Nakamura+ submitted)
Many samples are PWN
HESS J1837-069Chandra(Gotthelf+ 2008)
HESS J1718-3825XMM-Newton(Hinton+ 2007)
(See also Pühlhofer’s invited talk, Uchiyama+ poster D12)
1.4. X-ray follow-ups of TeV unIDs (2): unknown categoriesNo counterpart !!
HESS J1616-508Suzaku (Matsumoto+ 2007)
Molecular cloud ??
Galactic center regionradio obs. (Aharonian+ 2006)
Some source but unID !!
HESS J1614-518Suzaku (Matsumoto+ 2008)
Compact unID sources !!
HESS J1804-218: Suzaku (Bamba+ 2007)
Many kinds of TeV unIDs !
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 !
This one !
-> Suzaku is the best tool for the counter part search: low and stable bgd
50ks x 4 pointingmapping obs.
color: TeVcontour: molecular cloud
0.5 deg
0.5-2.0 keV (Suzaku)contour: HESS
2.2. Suzaku image of HESS J1745-303 (1)
SNRsG359.0-0.9, G359.1-0.5
(Bamba+ 2000)
ROSAT sources
No X-ray !
2.0-8.0 keV (Suzaku)contour: HESS
2.3. Suzaku image of HESS J1745-303 (2)
No X-ray !
2.4. Suzaku image of HESS J1745-303 (3)
Some excess on HESS J1745-303 ??
6.4 keV ion line (Suzaku)contour: HESS
src
bgd1
bgd2
3.1. Spectral Analysis (1) continuum comp.
Src: TeV peak regionbgd: TeV free region
Compare the flux (Assuming Gamma = 2.0)
F2-10 keV < 2.1 x 10-13 ergs cm-2s-1
c.f. F1-10 TeV = 5.2 x 10-12 ergs cm-2s-1
F1-10TeV
F2-10keV
> 25 one of the most X-ray faintTeV unIDs!
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 ± 0.03bgd1: 5.9e-8 ± 2.2e-8 1.2e-7 ± 0.2e-7 0.49 ± 0.20
Src region has stronger 6.4 keV line although the statistics is not enough …
Src
bgd1
5.9keV(MnKa: bgd)
6.4keV(neutral Fe)
6.7keV(He-like Fe)
Ni Ka(bfd)
3.2. Spectral Analysis (2) neutral iron line
total excess:6.1x10-6 ph cm-2s-
1
src
bgd1bgd2
(Bitran+ 1997)(Aharonian+ 2008)
4.1. Discussion 1: Nonthermal continuum emission
F2-10 keV < 2.1 x 10-13 ergs cm-2s-1
F1-10 TeV = 5.2 x 10-12 ergs cm-2s-1
F1-10TeV
F2-10keV
> 25
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 MCsMC 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
4.2. Discussion 2: neutral iron lineneutral iron line near the GC, coinside with MC = reflection on the MC by the past bright GC
(Koyama+ invited talk, Murakami+ 2001)
Sgr B2 HESSJ1745line Int. 5.6e-5 6.1e-6MMC 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
The neutral iron line can be explainedby 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
HESSJ1745: 7.0e-6 ph cm-2s-1
Where is the CR source ?? G359.1-0.5 ??
Cosmic rays make TeV emission with attacking MC ???(Aharonian+ 2006)
5. Summary