1. Chandraによる SN1006衝撃波面の詳細観測
SN 1006 with ASCA
馬場 彩、山崎 了、植野 優、小山 勝二
(京都大学)

2. 1. Introduction “How are cosmic rays accelerated up to TeV?”
Basic concept: Diffusive Shock Acceleration (DSA)
(Bell 1978; Blandford & Ostriker 1978…)
Koyama et al.(1995)
Discovery of synchrotron X-rays
from the shell of SN 1006
SN1006:
type Ia
d=1.8kpc
10´
Next problem: More realistic model
“How do the non-thermal electrons distribute on the shock?”
Spatial and spectral studies with Chandra

3. 1.2. Chandraの特長 Chandra ACIS-Sで観測 (68 ksec) 高空間分解能 位置分解能 ～ 0.5″!
→ 衝撃波前後面の詳細構造が分かる
2. 低エネルギーまで感度あり
0.3 keV – 10.0 keVに感度 (ACIS-S)
→ 酸素のラインも見ることが出来る
(特に低温プラズマの診断に有利)
Chandra ACIS-Sで観測 (68 ksec)

4. 2.1. Image and spectrum thermal non-thermal extended sharp
outward
= upstream
2.1. Image and spectrum
Energy (keV) 1 5
0.3
inward
= downstream
thermal
extended
non-thermal
sharp
SN1006 NE shell
How large are the scale length of
non-thermal component?
0.3 – 2.0 keV
2.0 – 10.0 keV

5. 2.2. Analyses method We want to know: upstream
downstream
the scale length of non-thermal component in
outward
= upstream
inward
= downstream 40
shock
counts 20 wu wd
2.0 – 10.0 keV
arcsec 20 40

6. 2.3. Fitting results Upstream 0.04 pc 0.01 pc Downstream 0.2 pc
2 – 10 keV
Upstream
0.04 pc
0.01 pc
Downstream
0.2 pc
0.05 pc
Mean value……………….
Minimum value……….…..

7. 3.1. Discussion (1) the observed and derived parameters
Observed parameters:
Derived parameters from DSA:
Emax , Bd
1. The wide band spectrum
nbreak = x1017 Hz
+0.7
-0.7
EmaxBd0.5 = erg G0.5
+0.04
-0.06
2. The diffusion coefficient K
wu = Ku uu
wd = Kd ud
K =
xEmaxc
3eB
x ~ > 1 B dB
Emax Bd
> 6.4x106erg/G
uu = 4ud = us = 2600 km/s
(Winkler & Long 1997)
3. The acceleration and loss
tacc = = 1010s
4(Ku+Kd)
us2
tacc < tsync
EmaxBd2 < 6.5x10-8 erg G2
tsync= 6.3x102Emax-1Bd-2

8. 3.2. Discussion (2) the Emax – Bd relation
log (Emax/eV) 14 13
log (Bd/G) -6 -3
from nbreak
from Kd and x
from tacc
Emax ~ 30 TeV
Bd ~ 30 mG
xd < 1.3
shock Bd ?
Highly turbulent magnetic field!
downstream e-

9. 3.3. Discussion (3) in upstream
Emax ~ 30 TeV
Bd ~ 30 mG
Bd < Bu < Bd 1 4
7 mG < Bu < 30 mG
The gyro radius in upstream rg:
Emax
eBu
0.001 pc < rg = < pc
~ wumin = 0.01 pc !
shock
Conventional DSA cannot explain the result. Bu Bd
the magnetic field in upstream
nearly parallel to shock plane
the new acceleration mechanism
e.g. Surfing acceleration (Hoshino & Shimada 2002)
downstream
Further analyses of SN 1006 and other SNRs

10. 4. Other SNRs (1) Young SNRs
Cas A
Kepler
Tycho
0.06pc
0.04pc
0.01pc
0.007pc
0.02pc
0.02pc

11. 4. Other SNRs(2) middle aged SNRs
RCW86
0.5pc
0.1pc
0.6pc
0.08pc

12. 5. Summary We resolved non-thermal emission
from thermal plasma in spatially and spectroscopically.
2. The non-thermal filaments have
very small scale length!
3. The conventional DSA should be revised
to explain the small scale length.
the magnetic field parallel to shock plane in upstream?
new acceleration mechanism? or
4. The analyses of other SNRs is important!