1. Hironori Matsumoto (Kyoto University) and The Suzaku team
X-ray Observations of the HESS Unidentified Sources from the Galactic Plane
Hironori Matsumoto (Kyoto University)
and
The Suzaku team

2. Thank you very much for coming to the Suzaku (my) conference!
“God(?) bird” Suzaku by A. Bamba

3. Talk outline Motivation Suzaku XIS observations HESSJ1614-518
Discussion
Summary

4. Where are proton accelerators? How can we find out?
Look for objects bright in TeVγ-rays but dim in X-rays!
TeV γ-ray … protons or electrons
synch. IC π0
X-ray
γ-ray
E2f(E)
Energy
High energy electrons should emit synchrotron X-rays!
Flux(X)～0.9x(B/3μG)2xFlux(TeV)
To look for a dim and diffuse object, the Suzaku XIS is the best tool.

5. HESS Galactic Plane Survey
First systematic Galactic plane survey with TeV γ-ray (>200GeV)
HESSJ
HESSJ
HESSJ
Select three extended objects
14 new objects.
Gal. Cent.
Most have no obvious counterparts.
(Aharonian et al. 2005, 2006)

6. HESSJ1614-518 Brightest among the new objects. XIS FOV 50ks HESSJ1614
HESS TeV γ-ray image (excess map)
Provided by S. Funk (MPI)
Brightest among the new objects.
XIS FOV
50ks
HESSJ1614
(l, b)=(331.52, -0.58)

7. XIS FI (S0+S2+S3): 3-10keV band
XIS image
XIS FI (S0+S2+S3): 3-10keV band
50ks
TeVγ-ray
Swift XRT also detected
(Landi et al. 2006)
Extended object

8. XIS spectra Featureless non thermal Featureless, but extremely soft
NH=3.8(±0.9)e21cm-2
Γ=2.0(±0.1）
F(2-10keV)=5.3e-13erg/s/cm2
Featureless
non thermal
NH=9.9(±1.0)e21cm-2
Γ=3.4(±0.2）
F(2-10keV)=2.4e-13erg/s/cm2
Featureless,
but extremely soft

9. HESSJ1616-508 XIS FOV HESSJ1616 45ks (l, b)=(332.391, -0.138)
HESS TeV image (excess map)
(l, b)=( , )
XIS FOV
45ks
Provided by S. Funk (MPI)
HESSJ1616

10. XIS image 45ks No X-ray counterpart F(2-10keV)<3.1e-13 erg/s/cm2
XIS FI (S0+S2+S3): 3—12keV
TeV image
See Matsumoto et al. 2006, PASJ, Suzaku Special Issue
(astro-ph/ )
45ks
No X-ray counterpart
F(2-10keV)<3.1e-13 erg/s/cm2

11. HESSJ1804-216 Softest among the new objects. XIS FOV 40ks HESSJ1804
HESS TeV γ-ray image (excess map)
Provided by S. Funk (MPI)
(l, b)=(8.401, )
XIS FOV
40ks
Softest among the new objects.
HESSJ1804

12. XIS image XIS FI (S0+S2+S3): 3-10keV src2 src1 src1: point-like
Swift XRT (Landi et al. 2006)
Chandra (Cui & Konopelko 2006)
TeV image
src1
src2
src1: point-like
src2: extended
or multiple
40ks

13. XIS spectra src2 src2: extended src1 src1: point-like src1 src2 Γ
-0.3±0.5
1.7±1.2 NH
(1022cm-2)
0.2(<2.2)
11±8
F(2-10keV)
10-13erg/s/cm2
2.5
4.3
src1: point-like
See Bamba et al. 2006, PASJ, Suzaku Special Issue (astro-ph/ )

14. Gallery
HESSJ1614
HESSJ1616
HESSJ1804
Hard
X-ray
TeV

15. TeV vs X-ray Extremely large!! Γ(TeV) > Γ(X)
F(1-10TeV)
erg/s/cm2
Γ(X)
F(2-10keV)
F(TeV)/F(X)
HESSJ1614
2.46
1.8e-11
2.0
5.3e-13 34
HESSJ1616
2.35
1.7e-11
---
<3.1e-13
>55
HESSJ1804
2.71
1.0e-11
1.7
4.3e-13 23
Γ(TeV) > Γ(X)
Extremely large!!
Good candidates for proton accelerators
Cf. Crab ～0.0027
RXJ ～0.06

16. If we assume electrons…
Very weak B
(B<1μGauss)
realistic?
Suzaku upper limit or
Strong cut-off
HESSJ1616 SED
Inconsistent with Γ(TeV)>Γ(X)? =
Γ(Synch)

17. Summary Suzaku observed three unID extended HESS objects.
HESSJ , HESSJ , HESSJ
All have extremely large F(TeV)/F(X)
Hard to explain the ratio by high energy electrons.
Good candidates for proton accelerators.
“What are they?” It’s still an open question.
(Talks by G. Puehlhofer, R. Yamazaki)

18. HESSJ
3.0—10.0keV
0.4—3.0keV

19. HESSJ
0.4--3keV
3--12keV

20. HESSJ
0.4-3keV
3-10keV

21. E_sync = 4keV x (B/10uG) x (E_e/100TeV)^2
Flux(X)～0.9x(B/3μG)2xFlux(TeV)

22. Where are proton accelerators? How can we find out?
synch. IC π0
X-ray
γ-ray
E2f(E)
Energy
X-ray
TeV γ-ray
electron
synchrotron
inverse Compton
proton
--- π0
High energy electrons emit X-rays very easily!
Look for objects bright in TeVγ-ray and dim in X-ray!