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「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 !