「すざく」による SN1006 の観測Suzaku observations of SN1006

Aya BAMBA(ISAS/JAXA)

XIS (X-ray Imaging Spectrometer)Improved X-ray CCD with high efficiency

and good energy responseLow and stable backgroundEnergy band : 0.2-12keV

XRT (X-Ray Telescope)Large effective area

410cm2 @1.5keV

HXD (Hard X-ray Detector)Wide energy band Si-PIN (10-70keV) & GSO Scinti. (40-600keV)Non-imaging detector, but low background

XRT

XIS

HXD

Suzaku: Jp-US X-ray satelliteSuccessfully launched on 2005 July 10th.

Previous SN1006 observations

radio: faint continuumno information of MC

X-ray: synchrotron X-rays !(~10/265 SNRs)thermal X-rays

Halpha: bright in NW rim proper motion is measuredTeV: detected faint shellsoptical: detection of SN 1000yrs ago type Ia SN @NASA/HEASARC

SN1006 is a milestoneto understand the shock acceleration in SNRs

What can Suzaku achieve ?

- X-ray diagnostics of thermal emissiondensity, temperature, ….-> topic 1

- parameters of synchrotron X-raysbending ??-> topic 2

Suzaku observations

src 4pointingbg 2pointingtotal 200ks

FOV of XISFOV of HXD/PIN 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 regionPlenty of emission lines

(Yamaguchi+08)

the first detection of iron K line

strong H-like and He-like O lines

thermal spectrum of whole SNR

NH [cm-2] 6.8x1020

VNEI 1 (ejecta 1) kT [keV] 1.2 nOneV [cm-3] 4.19 (4.05-4.32)x1052

VNEI 2 (ejecta 2) kT [keV] 1.9 nOneV [cm-3] 3.82 (3.77-3.89)x1053

NEI (ISM) kT [keV] 0.45 nHneV [cm-3] 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

(Katsuda+09)

filaments are moving in these 9 yrs !

2000 - 2008v = 0.48”/yr ~ 5000 km/s

ambient density ~ 0.085 cm-3

ISM density is very low !

topic 2:Parameters of synchrotron X-rays

Spectra of whole remnant: XIS+HXDPIN statistic errPIN systematic err

excess: 1% of bgd

The most tight upper-limit(2.7x10-5 ph/cm2/s in 10-15 keV)

XIS spectra (1)

large residuals from power-law model

emission lines + hard emission3 kT plasma (Yamaguchi+08) + power-law model

XIS FIXIS BI

synchrotron model with bending: srcut modelcut-off ? -> Emax of e, B

We need spectrawith good statistics -> Let’s see SN1006

nem

issi

onncutoff~ Emax

2B

G-12

Sync. EmissionFrom Power-law electrons

E

N(E

)

Emax

G

exp.

n

Sync

. em

issi

on

E2B

electron distribution

emission from an e

(SRCUT model)

3 kT plasma + srcut modelsync. emission from

electrons with PL + exp. cutoff distribution

spectral index at 1GHz: a=0.57

no residual !

non-thermal emission hassignificant cut-off !

ncutoff = 5.69 (5.67-5.71)x1016 Hz

XIS FI XIS BI

XIS spectra (2)

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 ?cutoff freq. = 1.6x1016 B

1microGE

10TeV2

[Hz](Reynolds 1998)

assumption: B=40microG (10microG outside)(Bamba+ 2003)

-> E = 9.4 TeV

B: magnetic field 　 E: max E of e

difference of cut-off in NE and SW rimsdifference of B and/or Emax ?

-> difference of acc. efficiency ?

assump. B=40microGE = 10 TeV @ NEE = 8.5 TeV @SW

more detailed model is now needed to understand the cut-offNow we have TeV emission ! SED is available.

non-thermal flux(10-12ergs s-1cm-2arcmin-2 (2-10 keV))

ther

mal

flux

(erg

s s-

1 cm

-2ar

cmin

-2 (

0.5-

2 ke

V))nonthermal flux vs. thermal flux

even low density, it might affect CR acceleration

north

inner east(Bamba+07, regected by J.Hughes)

Where is accelerated protons ?In the case of old SNR G359.1-0.5 …

0.5-2.0 keV (Suzaku)contour: HESS

SNRsG359.0-

0.9, G359.1-0.5

(Bamba+ 2000)Only

thermal

TeV gamma-rays !

6arcmin

(Bamba+09)

neutral iron mapexcess !

6arcmin

(Bamba+09)

molecular cloud

past activeGC

TeV emission is from accelerated protons ?

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 morefor proton acceleration study.

3rd Suzaku conference“the Energetic Cosmos: from Suzaku to Astro-H”

June 29 – July 2, Otaru, Hokkaido, JapanTopics:

- 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 IXOabstract deadline: Mar. 16registration deadline: Apr. 13

Let us enjoyfresh topics and Sushi !