Alessia Ritacco on behalf of NIKA collaboration 6

CALIBRATION

Goals: !

• Characterisation of instrumental polarisation !

• Calibration in polarisation angle

HOW?!• Planets: unpolarised sources!

• Quasars: polarised radiogalaxies!

• Extended known sources

Alessia Ritacco on behalf of NIKA collaboration 7

Uranus observations

Template of the I P leakage effect

Uranus @ 2mm!February 11th, 2015 Ideal case

QI UI

-60 -40 -20 0 20 40 60arcsec

-60

-40

-20

0

20

40

60

arcs

ec

I map 2mm channel

-1.72

2.42

6.57

10.71

14.86[Jy/beam]

-60 -40 -20 0 20 40 60arcsec

-60

-40

-20

0

20

40

60

arcs

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Q map 2mm channel

-0.20

-0.08

0.05

0.17

0.30[Jy/beam]

-60 -40 -20 0 20 40 60arcsec

-60

-40

-20

0

20

40

60

arcs

ec

U map 2mm channel

-0.20

-0.08

0.05

0.17

0.30[Jy/beam]

Systematic effect

-60 -40 -20 0 20 40 60arcsec

-60

-40

-20

0

20

40

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arcs

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-0.18

3.55

7.27

10.99

14.72[Jy/beam]

I

-60 -40 -20 0 20 40 60arcsec

-60

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-20

0

20

40

60

arcs

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-0.20

-0.08

0.05

0.17

0.30[Jy/beam]

Q

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-60

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0

20

40

60

arcs

ec

-0.20

-0.08

0.05

0.17

0.30[Jy/beam]

U

I Q U

Alessia Ritacco on behalf of NIKA collaboration 8

Systematic effect correction: quasar example3C273 @ 2mm!

February 17th, 2015Systematic effect

Q U

IQ U

Good subtraction of the systematic signal

+

I

+

QI U

QI U

I Q

+

U

I

+

Q

+

U-60 -40 -20 0 20 40 60

arcsec

-60

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0

20

40

60

arcs

ec

I map 2mm channel

-0.49

1.57

3.63

5.69

7.75[Jy/beam]

-60 -40 -20 0 20 40 60arcsec

-60

-40

-20

0

20

40

60

arcs

ec

Q map 2mm channel

-0.06

5.0E-03

0.07

0.13

0.20[Jy/beam]

-60 -40 -20 0 20 40 60arcsec

-60

-40

-20

0

20

40

60

arcs

ec

U map 2mm channel

-0.30

-0.22

-0.14

-0.05

0.03[Jy/beam]

-60 -40 -20 0 20 40 60arcsec

-60

-40

-20

0

20

40

60

arcs

ec

I map 2mm channel

-0.62

1.45

3.51

5.57

7.64[Jy/beam]

-60 -40 -20 0 20 40 60arcsec

-60

-40

-20

0

20

40

60

arcs

ec

Q map 2mm channel

-0.15

-0.06

0.03

0.11

0.20[Jy/beam]

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-60

-40

-20

0

20

40

60

arcs

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U map 2mm channel

-0.15

-0.06

0.03

0.11

0.20[Jy/beam]

Maps corrected

I Q U

I Q U

Alessia Ritacco on behalf of NIKA collaboration 9

KNOWN CALIBRATION SOURCE: CRAB NEBULA

Polarised intensity

GOOD AGREEMENT WITH XPOL EXPERIMENT (Aumont et al. (A&A), 514, A70)

150 GHzI

Q

U

Alessia Ritacco on behalf of NIKA collaboration 10

CONCLUSIONS & PERSPECTIVES

Polarisation setup validated with NIKA!

Preliminary analysis shows a good

agreement with other experiments!

Analysis on extended sources in progress!

NIKA2 first polarised light in 2016

NIKA Collaboration

Thanks !

Alessia Ritacco on behalf of NIKA collaboration 12

BACK-UP SLIDES

Alessia Ritacco on behalf of NIKA collaboration 13

NIKA vs XPOL

Ref: Aumont et al. (A&A), 514, A70 (2010)

NIKA XPOL

Alessia Ritacco on behalf of NIKA collaboration 14

Polarisation integrated in NIKA band

Alessia Ritacco on behalf of NIKA collaboration 15

Polarisation with NIKA2

Bands : 1.15 & 2.05 mm!Beam (FWHM) : 12 ‘’ & 17’’!# Detectors : 2x2000 & 1000!Field of view: 6.5 arc-minutes!Sensitivity : 30 & 20 mJy s1/2

DETECTION  STRATEGY:  HWP  @  300K+  WIRE  GRID  @  100  mK

224 & 1322.2 arcminutes

NIKA