2007 01 15 ppt 07 Xray Polarimetry Missions

論文紹介_2007 -01 -15. ppt 論文紹介07: X-ray Polarimetry Missions January 15, 2007 Tsunefumi Mizuno Hiroshima University M. Mc. Connel "Status and Future Prospects for gamma-ray Polarimetry" and references therein (X-Ray Polarimetry Workshop at SLAC/Stanford, 2004; http: //www-conf. slac. stanford. edu/xray_polar/XRay%20 presentations/Mc. Connell_Gamma_Review. pdf) 1

論文紹介_2007 -01 -15. ppt Progress of X-ray Astrophysics Energy Resolution at 5. 9 ke. V Einstein Tenma (IPC) (SPC) Uhuru ASCA (SIS) Chandra Suzaku (HEG) (XRS) Sensitivity Uhuru Einstein (IPC) Point Spread Funciton Chandra (ACIS) Einstein ROSAT Chandra (IPC) (PSPC) (ACIS) • In X-ray Astrophysics, the imaging capability, spectral resolving power and point source sensitivity have improved by orders of magnitude. However, … 4

論文紹介_2007 -01 -15. ppt (Little) Progress of Polarization Measurement Crab Nebula Polarization measurement with OSO-8 (1976) Modulation curve for 2. 6 ke. V Crab Nebula signal+BG BG Intensity of the source from which pol. was detected • Two carbon Bragg diffraction polarimeters @2. 6 ke. V and 5. 2 ke. V • 19. 2+-1. 0 % polarization from Crab Nebula (Weisskopf et al. 1976) • Signal/BG ratio was ~9(2. 6 ke. V)/2(5. 2 ke. V) • No significant (3 s) pol. detection from Crab pulsar No obs. ! Results has not been surpassed for ~30 years 5

論文紹介_2007 -01 -15. ppt What can polarization tell us about HE objects? かに星雲+かにパルサー Nebula+pulsar 1 Crab/~0. 1 Crab --- Processes known to polarize hard X-rays --Vela X-1 pulsar ~1 Crab • Synchrotron pol. vector is perpendicular to magnetic field Heremission: X-1 ~0. 1 Crab and can tell 4 U 0115+63 us the direction of the field. ~0. 1 Crab • SNRs, Pulsars, AGN jets, micro-quasars and GRBs V 0332+53 ~0. 1 Crab • Compton Scattering: pol. vector. BH is perpendicular to the plane of Cyg X-1 ~1 Crab scattering and can tell us the geometry of the photon source and the GX 339 -4 ~0. 1 Crab IE 1740. 7 -292 ~0. 1 Crab scatterer (e. g. , accretion disk) GS 2000+25 ~0. 1 Crab • BH binaries, Seyfert AGNs GRS u. QSO ~0. 1 Crab • Propagation of 1915+105 photons in strong magnetic field: photons with pol. GRO J 1655 -40 vector perpendicular to magneticu. QSO field are highly~1 Crab absorbed. Good for Mkn 501 electrodynamics AGN and reconstruction ~0. 1 Crab of the test of quantum Cen. A ~0. 1 Crab direction of the magnetic field. et al. 2005, proc. SPIEなどより) • Isolated pulsars, (Kataoka NS binaries with a strong cyclotron line. 磁場や散乱の絡む系(ほぼ全ての非熱的放射)で、系のジオ メトリを直接探る唯一の手段 詳しくは巻末の資料も参照(林田さんのトラペからいろいろ借用) 6

論文紹介_2007 -01 -15. ppt Concept of the Compton Polarimeter Utilize azimuthal angle asymmetry of Compton Scattering to measure hard X-ray polarization pol. vector Klein-Nishina cross section Azimuthal angle distribution 90 degree scattering is the best for the polarization measurement Modulation Factor is defined as 0 degree 45 degree 135 degree 90 degree 8

論文紹介_2007 -01 -15. ppt GRAPE Mission (1) • Mc. Conell et al. 1999, IEEE Trans. Nucl. Sci. 46(4), 890 • Mc. Conell et al. 2004, Proc. SPIE 5165, 334 • Bloser et al. 2006, Ch. JS 6, 393 • Scatterer: Ø 60 plastic. scintillators: 5 mm x 50 mm • Absorber: ØCs. I or La. Br 3 MAPMT (H 8500) • モジュール構造。6 x 6=36 or 10 x 10=100 or 20 x 20=400。50 -300 ke. V • 細かくセグメント化し、MFを上げる • MAPMTMで読み出し • 視野は 0. 1 sr程度。全体をantiで囲う。 • 具体的なフライトの計画は(多分)まだない。 10

論文紹介_2007 -01 -15. ppt GRAPE Mission (2) • 2 x 2=4 modulesの場合の有効面積およびMF • MF~0. 4だが、効率は数% Modulation Factor 6 x 6=36 modules (geom. area~1000 cm 2) geom. area~100 cm 2 30 300 11

論文紹介_2007 -01 -15. ppt Grape Mission (3) N=36, 0. 1 sr (1 m length), perfect anti-coincidence shield Crab vs. BG Crab Nebula BG ~ 1 Crab 6 hのフライトで、20%程度の偏光を検出可能? 100 m. Crab以下はほぼ絶望的 30 300 12

論文紹介_2007 -01 -15. ppt CIPHER Mission (1) • Caroli et al. 2000, NIMA 448, 525 • Caroli et al. 2000, Proc. SPIE 4140, 573 • Curado et al. 2003, Proc. SPIE 4843, 543 • Curado et al. 2003, Experiment Astronomy 15, 45 28 x 35 cm 2 18 x 15 cm 2 Exposed: maskを考慮した面積 Efficient: active area x efficiency • Coded Maskと 1 cm厚のCd. Te検出器の組み合わせ。(2 x 2 mm 2)x(64 x 64)x 4 ~160 cm 2 • 1次元pixel化Cd. Teを横に並べ 2次元イメージング。隙間が非対称なので、4モジュールを 90度 ずつまわして配置。 • TungstenとCs. Iでシールド。視野は 10度程度(~0. 03 sr) • 100 ke. V以下はイメージングモード。100 ke. V以上でpolarimeterモード (100 ke. V-1 Me. V) 13

論文紹介_2007 -01 -15. ppt Po. GO Mission (1) Side BGO Scint. Shield (BG rejection. ) Slow Plastic Scint. Collimator (FOV: 5 deg 2) Fast Plastic Scint. (Pol. measurement) Bottom BGO PMT assembly (low noise) • 日米欧の国際協力、2009年気球観測 目標。25 -80 ke. V • 「すざく」HXDで用いられた井戸型フォス ウィッチのデザインを採用。geom. area=930 cm 2 Øfast plastic scinti. : 散乱体と吸 収体を兼ねる Øslow plastic: collimator ØBGO: active shield • Pb/Sn+slow plasticで視野を絞る(1. 2 m. Sr)。BGOとあわせ、徹底した低バックグラウンド化 をはかる。 • 高感度PMTによりエネルギー下限を下げる。 • 217 units (main)+54 units (side BGO): 多チャンネル高速処理と波形弁別が鍵を握る。 17

論文紹介_2007 -01 -15. ppt Po. GO Mission (3) 大面積、低バックグラウンド Expected source and BG spectra かに星雲なら数%、1/10の強度の天体でも 10 -20%の偏光まで検出可能 100 m. Crab(incident) 100 m. Crab (detected) 100 m. Crab BG total (CXB/ atmospheric downward/upward) Crab Nebula Full simulationによる評価。BG~10 -20 m. Crab (極めて低いバックグラウンド) 20 20 100 ke. V 200 19

論文紹介_2007 -01 -15. ppt Appendices 21

論文紹介_2007 -01 -15. ppt 偏光で探る天体物理 (1) Dyks and Rudak, Ap. J, 2003 単独パルサーの放射機構 Polar Cap Model P 2 Polar cap Caustic 偏光方位角 強度 Outer gap モデル毎に異なる偏光度、方 位角が予想される (Alice Hardingによる計算) 偏光度 P 1 Outer Gap Model Slot Gap/Caustic Model 位相 22