Probing Particle Acceleration with Probing Particle Acceleration with X-ray/Gamma X ray/Gamma ray/Gamma-ray ray/Gamma ray ray Polarimetry ray Polarimetry Polarimetry Polarimetry Mar 22, 2012 ASTRO-H Session, ASJ meeting T. Mizuno, H. Takahashi, Y. Fukazawa T Mi H T k h hi Y F k (Hiroshima Univ), H. Tajima (Nagoya Univ.), T. Tanaka, Y. Uchiyama (KIPAC/Stanford), S Takeda H Odaka S Watanabe G Sato S. Takeda, H. Odaka, S. Watanabe, G. Sato, M. Kokubun, T. Takahashi (ISAS/JAXA), K. Nakazawa (Tokyo Univ.), P. Coppi (Yale Univ.) and T. Tamagawa (RIKEN) (Yale Univ.) and T. Tamagawa (RIKEN) 1
ASTRO ASTRO- -H SGD H SGD • Si-CdTe Compton Camera + BGO shiled • Constrain incident angle using Compton kinematics • Constrain incident angle using Compton kinematics – efficient background suppression m e c 2 − m e c 2 cos θ = 1 + E 1 + E 2 cos θ = 1 + − E 2 Background Level Background Level Suzaku HXD-GSO Tajima+ 10 Tajima+ 10 0.1 Crab Compton Scat. Astro-H SGD Photo-abs. BG<=100 mCrab 2
ASTRO ASTRO- -H SGD as a H SGD as a Polarimeter Polarimeter • Si-CdTe Compton Camera + BGO shiled • Constrain incident angle using Compton kinematics • Constrain incident angle using Compton kinematics – efficient background suppression – polarization measurement p m e c 2 − m e c 2 cos θ = 1 + cos θ = 1 + E 1 + E 2 − E 2 Takeda+ 10, NIMA prototype test Tajima+ 10 Proc. SPIE Compton Scat. Photo-abs. M 0 58 (80 300 k V) M=0.58 (80-300 keV) w/ flight configuration 3
X- -ray/Gamma ray/Gamma- -ray ray Polarimetry Polarimetry • Why polarization? (1) place constraints on source geometries (2) break model degeneracy geometries (2) break model degeneracy – Synchrotron emission (magnetic field) – Compton up-scattering radiation (see photons, disk) – Pol. due to QED or general relativity (constraints on P l d t QED l l ti it ( t i t fundamental physics and compact object) BHB, AGN PWN Pulsar Magnetic field, Pulsar emission model, Accretion disk, Accelerated electrons QED Jet X/ γ -ray pol. not subject to Faraday rotation/depolarization 4
X- -ray/Gamma ray/Gamma- -ray ray SpectroPolarimetry SpectroPolarimetry • Measuring energy dependent polarization is crucial to disentangle emission mechanisms disentangle emission mechanisms – transition from one pol. generation process to another may occur over broad energy range Blazar model (Poutanen94) Blazar model (Poutanen94) disk reflection model (Matt+93) disk reflection model (Matt+93) pol. vector � disk on flux 10% photo degree 1% 1% synchrotron h t pol. d e ol. degree total IC IC po 0.1% 3 10 keV 50 ** pol. may be low in EC ** 5
X- -ray/Gamma ray/Gamma- -ray ray SpectroPolarimetry SpectroPolarimetry • Measuring energy dependent polarization is crucial to disentangle emission mechanisms disentangle emission mechanisms – synergy with GEMS and PoGOLite will enhance science outputs PoGOLite (2012) 30-80 keV ballloon, Plasctic scint. lll l GEMS (2014-) ASTRO-H SGD (2014-) 2-10 keV 40-600 keV X-ray mirror+MPGD Si/CdTe Compton Camera 6
Case Study 1: Case Study 1: Cyg Cyg X X-1 • A toy model of polarized emission – Polarized jet seen by INTEGRAL/IBIS (67% pol., φ =140eg, Polarized jet seen by INTEGRAL/IBIS (67% pol., φ 140eg, contributing in E>100keV) – Disk reflection (3% pol. in 2-10keV and 10% pol. in 30-60 keV, φ 162deg (Long 80)) φ =162deg (Long+80)) • See how SGD (+others) can measure polarization Disk reflection HE Jet HE Jet ( (polarized) l i d) C Comptonization t i ti (polarized) (non-pol) A-H SGD pol. deg.=67+/-30% (E>=400 keV) (E> 400 keV) Long+80 2.6/5.2 keV Laurent+11 hint of weak pol. 7
SGD SGD Polarimetry Polarimetry of of Cyg Cyg X X-1 • Energy dependent polarization measurement w/ ASTRO-H SGD – disclose jet component hidden in Comptonization down to j p p 100 keV SGD Simulation, 300 ks 10% polarization @100-180keV INTEGRAL IBIS INTEGRAL IBIS Modulation Curve@250-400 keV (consistent with no pol.) 17% polarization @180-330keV 17% polarization @180 330keV Tanaka (Stanford) 8
Wide Wide- -band band Polarimetry Polarimetry of of Cyg Cyg X X-1 • Coordination with soft/hard X-ray polarimetry – disentangle disk reflection and jet emission disentangle disk reflection and jet emission – Compare directions of magnetic field (soft γ ), disk (X-ray) and jet (radio) HE Jet disk reflection disk reflection assumption: 100 ks obs. M=0.32 (GEMS, PoGO) SGD scaled from 300ks sim. SGD scaled from 300ks sim ee Disk reflecti n Disk reflection ol. degre ol. angle e (perpendicular to disk) HE jet (synchrotron) (synchrotron) po po 9
Case Study 2: Crab Nebula Case Study 2: Crab Nebula • A toy model based on the OSO-8/INTEGRAL data • PD=20%, PA=156deg (2.6/5.2keV): OSO-8, whole Nebula PD 20% PA 156d (2 6/5 2k V) OSO 8 h l N b l • PD=50%, PA=124deg (>100keV): INTEGRAL, aligned with pulsar rot. axis • Let’s assume PD=30% and PA=138deg (30-80keV) N PA @2.6/5.2 keV PD=20% E PA@ PA@ >100 keV 100 k V PD=50% 2’ 10
Case Study 2: Crab Nebula Case Study 2: Crab Nebula • A toy model based on the OSO-8/INTEGRAL data • SGD will confirm (or deny) the alignment SGD ill fi ( d ) th li t with pulsar rot. axis ASTRO-H/SGD (100 ks) • Constraints on PWN model w/ soft-X and gle hard-X data har X ata pol. an N PA @2.6/5.2 keV INTEGRAL/SPI PD=20% (1.2 Ms) (1.2 Ms) E ee ol. degre PA@ PA@ >100 keV 100 k V PD=50% po 2’ 11
Summary and Prospect Summary and Prospect • Pol. measurement by A-H SGD can place constraints on source geometry and break model degeneracy on source geometry and break model degeneracy ( qualitatively new type of information ) • Synergy with X-ray polarimeters will enhance science outputs t t • Two case studies are presented (Cyg X-1 and Crab; robust targets for SGD polarimetry) robust targets for SGD polarimetry) • Pol. measurement of pulsars and AGN flares will also be possible (to understand BG anisotropy is important) Thank you for your Attention Thank you for your Attention 12
Backup Slides Backup Slides Backup Slides Backup Slides 13
X- -ray/Gamma ray/Gamma- -ray ray SpectroPolarimetry SpectroPolarimetry • Measuring energy dependent polarization is crucial to disentangle emission mechanisms disentangle emission mechanisms disk reflection model (Matt+93) Strong polarization (67%) from pol vector � disk pol. vector � disk Cyg X-1 jet in HE (Laurent+11) Cyg X-1 jet in HE (Laurent+11) 10% 67% pol. e l. degree 1% po pol. <20% 0 1% 0.1% 3 10 keV 50 14
Polarization Polarization • 光源が非一様だと偏光が生じる – そろった磁場下でのシンクロトロン そろ た磁場 シ ク – 特定の面でのコンプトン散乱 Unpolarized Polarized 15
Crab Nebula Polarization (X Crab Nebula Polarization (X- -ray) ray) • Measured by OSO-8 (Bragg reflection) P Position Angle i i l 2.6 keV 5.2 keV Modulation @2.6 keV Weisskopf+78 16
Cyg Cyg X X- -1 Radio Jet 1 Radio Jet • 8 GHz images at three orbital phases (1998 August) Stirling+01 17
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