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Application of Michelson type bolometric interferometer to CMB B mode polarization observations. Makoto Hattori Astronomical Institute Tohoku University. Contents. Merit of interferometer for E ・ B mode separation and for minimizing contamination of instrumental polarization
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Application of Michelson type bolometric interferometer to CMB B mode polarization observations Makoto Hattori Astronomical Institute Tohoku University KEK
Contents • Merit of interferometer for E・B mode separation and for minimizing contamination of instrumental polarization • Demerit of interferometer with heterodyne receiver for CMB B mode experiments. • Bolometric interferometer as ideal instrument for B mode experiments. • Propose an B mode experiment with Michelson type bolometric interferometer. • Summary & bit about Akari/FIS all sky survey KEK
Single dish imaging obs. VS interferometer:E・B separation Single dish:ex. PLANCK Fourier Spectrum of I, Q,U, V are observed variables Interferometer: ex. DASI KEK
E・B separation by interferometer Stokes parameters In Fourier space:locally separable y X KEK
宇宙創世記: prove inflational universe and nature of DE by B mode obs..
Instrumental Polarization in Single dish (Huetal. (2003)) Pauli matrix expansion of P matrix Instrumental Jones matrix Monopole leakage due to cross polar mixing is significant KEK
Do not have to worry about Monopole leakage in interferometer Don’t do Try to measure directly by Prof.A.Suzuki KEK
CMB vs foreground Atmospheric emission Quantum limit of heterodyne receiver Atmospheric window @90GHz Synchrotron Cosmic window @70GHz Free-free intensity ΔT Thermal emission from dust mode frequency KEK
Interferometer with heterodyne receiversis not suitable to B mode observations Quantum limit of heterodyne receiver since it performs coherent detection DASI realistically Nosie levelis Quantum limit limited around cosmic window Construction of large element interferometer is practically hard. One receiveris mounted on focal plane of one telescope. KEK
Explosive improvement of sensitivity ofsingle dish obs. due to emergence of large format TES bolometer array SPT 330 elements Not quantum limit limited since incoherent detection
Interferometer with bolometer is the ideal coupling: bolometric interferometer It shares the both merit of interferometer and bolometer Fiseau type Michelson type
Application of Fiseau type:EPIC Timbie et al (2006) Adding type interferometer Data - Baseline fluctuation = Fringe KEK
Merit of Michelson type VS Fiseau type • Multiplying type bolometric interferometer is able to realize. • Broad band spectroscopy is possible: advantagiouscomponent • separation of foreground and CMB is possible. • Mathematical basis of the instruments • are fully explored. Luo, Ohta, Hattori, Chinone, et al. (2008in preparation) Path finder@NAOJ The moon interferogram 70GHz 170GHz Intrenal light path difference KEK
Problem inapplication of Michelson type to CMB B mode experiment D b D<b Required baseline length b=10cm@90GHz for l=100 • Low power of light collection • Hard to mount massive detector array • Lowest observable l is limited by D. KEK
HarryBotte New Michelson type bolometric interferometer satisfies D>b: MuFTPol Ohta, Hattori, Matsuo (2006,2007), Ohta et al. (2008 in prep.) y x Hattori, Ohta, Koga (2008 in preparation) Ex Telescope Ey D DET1,2,3,4=Ex()Ey =U±V b DET5,6,7,8 =(Ex+Ey)(Ex-Ey) =Q±V KEK
E・B mode separation by MuFTPol m 以下 N×Mpixel detector array n KEK
E・B mode separation by MuFTPol Base line vector // xdirection Sum up 10×10 pixels data The B mode are measured by direct observed varibales of DET1,2,3,4. KEK
Detector:8 set of 10×10TES array Operation temperature:300mK NEP~a few Time constant~msec Spider web and TES are going to be fabricated by MEMS at EsasiLabo. in Tohoku University SQUID time domain mutiplexing: cooperation of Prof.K.Irwin, NIST (USA) Any cooperations are very helpful and collaborations are very welcome. KEK
Observational site 1st session: Summit of Mt.Fuji Sekimoto et al. (1996) 80-100Gz with Δν=10GHz 1.4m telescope 0<b<40cm variable 2nd session Balloon 60-300GHzwith Δν=10GHz KEK
Summary • We propose Michelson type bolometric interferometer which is able relax D< b constraint • Application of this instrument to CMB B mode experiment is orthogonal to other projects, eg. B mode is the direct observable, minimizing instrumental polarization. • Summit of Mt.Fuji is atractive site for CMB experiment • By applying it to balloon born or space born mission, super broad band observation is possible which mazimize component separation of FG and CMB KEK
To improve physical prior information of dust components All sky diffuse map making @60, 100, 160μ with Akari/FIS all sky survey data (Doi (Univ.Tokyo), EtxaluuzeAzkonaga, M., Figueredo, E., White, G. (Open University),Chinone, Hattori (Tohoku University)、Nakagawa (JAXA)Akari team) 0.75’@160μ IRAS:12,25,60, 100μm, 2’@100μm KEK
CMB実験グループの立ち上げおめでとうございます。若い研究者にQUIET・Polarbearのデータにさわる機会を作って頂きありがとうございます。日本がCMB観測の歴史に一つでも足跡を残すことに、微力ながら手助けができれば幸いです。CMB実験グループの立ち上げおめでとうございます。若い研究者にQUIET・Polarbearのデータにさわる機会を作って頂きありがとうございます。日本がCMB観測の歴史に一つでも足跡を残すことに、微力ながら手助けができれば幸いです。 KEK
mm-wave sky –Foreground=CMB 23GHz Synchrotron Dust emission 33GHz 60GHz - 93GHz 41GHz Free-free = Synchrotron and dust are significantly polarized KEK
Cross Polarization mixing in MuFTPol Cross polarization transmitance of wire grid % 0.2%@100GHz KEK
MuFT仕様 当面 • Ground base observation • Φ1.4m ナスミス焦点望遠鏡 • ベースライン間隔:0<b<40cm可変 • 帯域80-100GHz・周波数分解能10GHz • 10×10 TESボロメータアレイ×8セット • (NEP~数×E-17 W/√Hz,τ~1msec) • 機械式冷却 • 目的:l~200-400の重力レンズ起源Bモード • パワースペクトル測定 将来 大気球帯域40-300GHz 理研仙台
Option U+Vのみ測定 デメリット:Δδの補正時の情報が減る メリット:cross polarization mixing が防げる。 光学系が簡略化 理研仙台
MuFTpathfinder@NROJ 月の観測データ (ルオ 2007) 世界で初めて積算型 ボロメトリック天体干渉計 の実現に成功 理研仙台
E and B mode polarization Stokes parameters Polarization vector Bmap must satisfy Emap must satisfy KEK
E・B mode separation In Real space:whole sky P map is neccessary B mode y In Fourier space:locally separable E mode X KEK