Download X-Ray Telescope

「すざく」によるSN1006の観測
Suzaku observations of SN1006
Aya BAMBA
(ISAS/JAXA)
Suzaku: Jp-US X-ray satellite
Successfully launched on 2005 July 10th.
XIS (X-ray Imaging Spectrometer)
Improved X-ray CCD with high efficiency
and good energy response
Low and stable background
Energy band : 0.2-12keV
XRT (X-Ray Telescope)
Large effective area
410cm2 @1.5keV
XIS
XRT
HXD (Hard X-ray Detector)
Wide energy band
Si-PIN (10-70keV) & GSO Scinti. (40-600keV)
Non-imaging detector, but low background
HXD
Previous SN1006 observations
radio: faint continuum
no information of MC
X-ray: synchrotron X-rays !
(~10/265 SNRs)
thermal X-rays
Halpha: bright in NW rim
proper motion is measured
TeV: detected faint shells
optical: detection of SN 1000yrs ago
type Ia SN
@NASA/HEASARC
SN1006 is a milestone
to understand the shock acceleration in SNRs
What can Suzaku achieve ?
- X-ray diagnostics of thermal emission
density, temperature, ….
-> topic 1
- parameters of synchrotron X-rays
bending ??
-> topic 2
Suzaku observations
FOV of XIS
FOV of HXD/PIN
src 4pointing
bg 2pointing
total 200ks
mapping of
whole remnant
Narrow band images of XIS-BI
He-like O line band
3 - 5 keV band
Distributions of thermal plasma and
non-thermal electron are different !
Topic 1:
X-ray diagnostics of thermal emission
XIS thermal emission in SE region
Plenty of emission lines
strong H-like and He-like O lines
the first detection of
iron K line
(Yamaguchi+08)
thermal spectrum of whole SNR
NH [cm-2]
VNEI 1 (ejecta 1)
kT [keV]
nOneV [cm-3]
VNEI 2 (ejecta 2)
kT [keV]
nOneV [cm-3]
NEI (ISM)
kT [keV]
nHneV [cm-3]
6.8x1020
1.2
4.19 (4.05-4.32)x1052
1.9
3.82 (3.77-3.89)x1053
0.45
3.45 (3.43-3.48)x1056
ISM density: 0.03 cm-3 (SE of SNR)
The density of acceleration site is very low !
(Yamaguchi+08)
(Bamba+08)
Proper motion of SN1006 NE shell
filaments are moving in these 9 yrs !
v = 0.48”/yr ~ 5000 km/s
2000 - 2008
ambient density ~ 0.085 cm-3
ISM density is very low !
(Katsuda+09)
topic 2:
Parameters of synchrotron X-rays
Spectra of whole remnant: XIS+HXD
PIN statistic err
PIN systematic err
excess: 1% of bgd
The most tight upper-limit
(2.7x10-5 ph/cm2/s in 10-15 keV)
XIS spectra (1)
emission lines + hard emission
3 kT plasma (Yamaguchi+08) + power-law model
large residuals from
power-law model
XIS FI
XIS BI
synchrotron model with bending: srcut model
cut-off ? -> Emax of e, B
N(E)
electron distribution
G
Sync. Emission
From Power-law electrons
exp.
E
emission
Sync.
emission
Emax
emission from an e
G-1
2
(SRCUT model)
n
E2B
n
We need spectra
with good statistics
ncutoff
~ Emax2B
-> Let’s see SN1006
XIS spectra (2)
3 kT plasma + srcut model
sync. emission from
electrons with
PL + exp. cutoff distribution
spectral index at 1GHz: a=0.57
no residual !
XIS FI
XIS BI
non-thermal emission has
significant cut-off !
ncutoff = 5.69 (5.67-5.71)x1016 Hz
XIS spectrum of each rim
NE rim
SW rim
cutloff freq.
6.66(6.58-6.69)x1016 Hz
4.68(4.64-4.73)x1016 Hz
cut-off freq. is larger in the NE rim
What determine cutoff energy ?
B
16
cutoff freq. = 1.6x10
1microG
B: magnetic field E: max E of e
E
10TeV
2
[Hz]
(Reynolds 1998)
assumption: B=40microG (10microG outside)
(Bamba+ 2003)
-> E = 9.4 TeV
difference of cut-off in NE and SW rims
difference of B and/or Emax ?
-> difference of acc. efficiency ?
assump. B=40microG
E = 10 TeV @ NE
E = 8.5 TeV @SW
more detailed model is now needed to understand the cut-off
Now we have TeV emission ! SED is available.
thermal flux
(ergs s-1cm-2arcmin-2 (0.5-2 keV))
nonthermal flux vs. thermal flux
(Bamba+07, regected by J.Hughes)
inner
east
north
non-thermal flux
(10-12ergs s-1cm-2arcmin-2 (2-10 keV))
even low density, it might affect CR acceleration
Where is accelerated protons ?
In the case of old SNR G359.1-0.5 …
SNRs
G359.0-0.9,
G359.1-0.5
TeV gammarays !
(Bamba+ 2000)
Only thermal
6arcmin
0.5-2.0 keV (Suzaku)
contour: HESS
(Bamba+09)
neutral iron map
excess !
6arcmin
molecular
cloud
past active
GC
TeV emission is
from accelerated protons ?
(Bamba+09)
Summary
 SN1006 is a milestone to understand
CR acceleration on shocks of SNRs.
 Suzaku capability to resolve thermal emission
shows us that the ISM density around
SN1006 is very low.
 Chandra detected proper motion of the NE rim.
 We detected the bending of synchrotron emission.
Now we have TeV emission, we will be able to
determine the Emax.
 Older SNRs should be studied more
for proton acceleration study.
3rd Suzaku conference
“the Energetic Cosmos: from Suzaku to Astro-H”
June 29 – July 2, Otaru, Hokkaido, Japan
Topics:
- Particle acceleration in cosmic shocks and jets
- X-ray diagnostics of cosmic hot plasma
- High energy aspects of the Milky Way
- Magnetic activity in stellar objects
- Primary and reprocessed emission from accreting objects
- X-ray vies of the evolution of the universe
- Highlights from the Fermi Space Gamma-Ray Telescope
- Status of the MAXI experiment
- From Suzaku to ASTRO-H and other missions
and further to IXO
abstract deadline:
Mar. 16
registration deadline: Apr. 13
Let us enjoy
fresh topics and Sushi !