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