Application of Michelson type bolometric interferometer to CMB B mode polarization observations

1

2008/3/13Application of Michelson type

bolometric interferometer to

CMB B mode polarization observationsMakoto HattoriAstronomical Institute

Tohoku UniversityKEK

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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

2008/3/13

KEK

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Single dish imaging obs. VS interferometer:E ・ B separation

)2,2(,),(

,)(),( )(22

vukbvu

eIdvuV yvxui

2008/3/13

KEK

Single dish:ex. PLANCK

Interferometer: ex. DASI

Fourier Spectrum of I, Q,U, V are observed variables

RR ,

R

4

E ・ B separation by interferometer2008/3/13

KEK

Stokes parameters

)2cos(),2cos(

22

11

taEtaE

y

x

sin2,cos2

,

,

21

21

22

21

22

21

12

aaVaaU

aaQ

aaI

In Fourier space:locally separable

)2cos()(ˆ)2sin()(ˆ)( ll lUlQlB

Ｘ

y

)( kl

l

宇宙創世記 :prove inflational universe and nature of DE by B mode obs..

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Instrumental Polarization in Single dish (Hu etal. (2003))Pauli matrix expansion ofP matrix

2131 VUQIEEP †

cccc

ccccinobs a

aJJPJP

12

21. 2

221,)1()1(

†

Instrumental Jones matrix

aVUQIVVaUQIUVUaQIQ

iii

i

i

12

12

21

22

2

2008/3/13

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Monopole leakage due to cross polar mixing is significant

6

0

10TTB

7

mMmM

')(

Don’t do

mTry to measure directly

by Prof.A.Suzuki

Do not have to worry about Monopole leakage in interferometer

aVUQIVVaUQIUVUaQIQ

iii

i

i

12

12

21

22

2

2008/3/13

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210

TT

TI

B

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CMB vs foreground2008/3/13

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Thermal emission from dust

Atmospheric emission

Quantum limit of heterodyne receiver

Synchrotron

Free-free

　　　 ΔT 　　

mode

frequency

inte

nsity Cosmic window

@70GHz

Atmospheric window@90GHz

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Interferometer with heterodyne receivers 　 is not suitable to B mode observations

21)2(4/1 t

hht

GHzKht

507.22/12

2008/3/13

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Quantum limit of heterodyne receiver since it performs coherent detection

realistically

GHzKh

207.23

Nosie level is Quantum limit limited around cosmic window

Construction of large element interferometer is practically hard. One receiver is mounted on focal plane of one telescope.

DASI

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CMB power spectrum2008/3/13

KEK

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Explosive improvement of sensitivity ofsingle dish obs. due to emergence of large format TES bolometer array

2008/3/13

SPT 330 elements

Not quantum limit limited since incoherent detection

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Interferometer with bolometer is the ideal coupling: bolometric interferometer

2008/3/13

It shares the both merit of interferometer and bolometerFiseau type Michelson type

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Application of Fiseau type ： EPIC

2008/3/13

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Timbie et al (2006)

-=

Adding type interferometer

Fringe

Baseline fluctuation

Data

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Merit of Michelson type VS Fiseau type• Multiplying type bolometric interferometer is able to

realize.• Broad band spectroscopy is possible: advantagious

component separation of foreground and CMB is possible.• Mathematical basis of the instruments are fully explored.

2008/3/13

KEK

Path finder@NAOJ

The moon interferogram

Intrenal light path difference

Luo, Ohta, Hattori, Chinone, et al. (2008in preparation)

70GHz 170GHz

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Problem in application of Michelson type to CMB B mode experimentD

b D<bRequired 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.

2008/3/13

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New Michelson type bolometric interferometer satisfies D>b: MuFTPol

2008/3/13

KEK

Ex

EyD

b

TelescopeDET1,2,3,4=Ex()Ey=U±VDET5,6,7,8=(Ex+Ey)(Ex-Ey)=Q±V

Ohta, Hattori, Matsuo(2006,2007), Ohta et al. (2008 in prep.)

Hattori, Ohta, Koga(2008 in preparation)HarryBotte

xy

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Observed variables of MuFTPol

)(2sin)()(2cos)(

)()()(21 )2()1(2

uVuU

AAddDD

VQDDVQDD

VUDDbc

u

87,65

,43,

2008/3/13

KEK

)(2sin)()(2cos)(

)()()(43 )2()1(2

uVuU

AAddDD

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E ・ B mode separation by MuFTPol

)'(2sin)'()'(2cos)'(

)'()'(')( )2()1(2

uVuU

AAddI nmnmnm

bc

u

以下 0),()()( )2()1()12( VAAA

''20

0')12(

'02

22/02/0

))'((sinc

)'()'('

)(),(

ui

nm

inmnm

e

UAdd

eIduJ

),( mnnm

))'((sinc)2(ˆ)2(ˆ'21

))'(sinc()2sin(

))2(2/sin()2sin(

))2(2/(sin

)(ˆ)2(ˆ'21

''''

'

'

'

'

''*

'22/12/

2/12/

2/12/

2/12/

uUukAd

vkvkM

ukukN

kUukAkddJ

y

y

x

x

Nn

N

M

Mnm

n

m

2008/3/13

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N×M pixel detector array

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E ・ B mode separation by MuFTPol

22

22

222

22

2 )(,)( sCcCuQcCsCuU Bu

Eu

Bu

Eu

GHzlcmb

100@40030

Base line vector // ｘ directionSum up 10×10 pixels data

Eu

Bu

Bu

CC

CuUs

22

222

01.0when

)(01.0

2008/3/13

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The B mode are measured by direct observed varibales of DET1,2,3,4.

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Detector:8 set of 10×10TES array

2008/3/13

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Operation temperature:300mKNEP ～ a few Time constant ～ msec Spider web and TES are going to be fabricated by MEMS at Esasi Labo. in Tohoku UniversitySQUID time domain mutiplexing: cooperation of Prof.K.Irwin, NIST (USA)Any cooperations are very helpful and collaborations are very welcome.

5.017 /10 HzW

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Observational site1st session: Summit of Mt.Fuji

2nd session Balloon 60 － 300GH ｚ with Δν=10GHz

2008/3/13

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Sekimoto et al. (1996)

80-100Gz with Δν=10GHz1.4m telescope 0<b<40cm variable

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Sensitivity of 1st session MuFT

sec10

:10/5

int

t

NS

2008/3/13

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SummaryWe 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

2008/3/13

KEK

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2008/3/13To improve physical prior information of dust componentsAll sky diffuse map making @60, 100, 160μ

with Akari/FIS all sky survey data (Doi (Univ.Tokyo),Etxaluuze Azkonaga, M., Figueredo, E., White, G. (Open University),Chinone, Hattori (Tohoku University) 、 Nakagawa (JAXA) Akari team)

IRAS: 12,25,60, 100μm, 2’@100μm

KEK

0.75’@160μ

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2008/3/13

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。

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Sensitivity of 1st session MuFT

sec10

:10/5

int

t

NS

2008/3/13

KEK

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mm-wave sky –Foreground=CMB

-

=

23GHz

33GHz

41GHz

60GHz

93GHz

2008/3/13

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Synchrotron

Dust emission

Free-free

Synchrotron and dust are significantly polarized

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Cross Polarization mixing in MuFTPol

0.2%@100GHz

2008/3/13

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ss p

olar

izatio

n tra

nsm

itanc

e of

wire

grid

%

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MuFT 仕様Ｇｒｏｕｎｄ　ｂａｓｅ observationΦ1.4m 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 － 100 ＧＨｚ・周波数分解能１０Ｇ Hz10×10 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

当面

将来大気球帯域 40 － 300GH ｚ

2008/2/20

理研仙台

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Option

)(2cos

)()()(21 )2()1(2

uEE

AAddDD

yx

errorzeropath todueerror path :

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

2008/2/20

理研仙台

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MuFT pathfinder@NROJ

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

月の観測データ（ルオ 2007)

2008/2/20

理研仙台

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Nasmis focus at Az-El telescope

2008/2/20

理研仙台

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E and B mode polarization

,0

U

QP

0

2

22

yx

yx

D

0 EPD

E map must satisfy

0 BPD

2008/3/13

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Stokes parameters

)2cos(),2cos(

22

11

taEtaE

y

x

sin2,cos2

,

,

21

21

22

21

22

21

12

aaVaaU

aaQ

aaI

B map mustsatisfy

Polarization vector

)0( E

)0( B

34

E ・ B mode separation

)2cos()(ˆ)2sin()(ˆ)( ll lUlQlB

In Real space:whole sky P map is neccessary Mapon Polarizati Measured:P

0)(),()( xGDxxGD BB

)'()'(')( 2 xPxxGxdx BB

In Fourier space:locally separable

2008/3/13

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BB DP ,0,0

Ｘ

y

)( kl

l

B modeE mode