Polarimetry at millimetre wavelengths with the NIKA and NIKA2 camera

Abstract : The role played by magnetic fields in the star formation process is an outstanding question of modern astrophysics. Herschel satellite observations have unveiled filamentary structures as the preferential sites of star formation. Complementary low resolution observations of dust polarisation by the Planck satellite have demonstrated that these filamentary structures are associated to well organised magnetic fields, which should play a major role in this process. A better understanding of this process requires detailed observations of galactic dust polarisation on scales of 0.01 pc to 0.1 pc. Such high resolution polarisation observations can be carried out at the IRAM 30 meter telescope using the recently installed NIKA2 camera, which features two frequency bands at 260 (polarised) and 150 (non polarised) GHz for a total of 3300 detectors, 12 and 18 arcsec FWHM resolution and Field of View (FoV) of 6.5 arcminutes diameter. The NIKA camera, which consists of two arrays of 132 and 224 LEKIDs (Lumped Element Kinetic Inductance Detectors) covering a FoV of ∼ 1.8 arcminutes at 1.25 (260) and 2.05 (150) mm (GHz), was installed at the IRAM 30 telescope from 2012 to 2015. NIKA was equipped of a room temperature polarisation system (a multi-layer half wave plate and a grid polariser facing the NIKA cryostat window), which permitted the simultaneous reconstruction of the three Stokes parameters, I, Q and U at 150 and 260 GHz. The purpose of this contribution is to discuss the polarisation performance of the NIKA camera. We present results on compact and extended sources obtained dur ing the February 2015 observational campaign. Furthermore, a first polarised light of NIKA2 instrument will be presented.
Complete list of metadatas

Contributor : Emmanuelle Vernay <>
Submitted on : Monday, August 22, 2016 - 9:50:11 AM
Last modification on : Tuesday, May 22, 2018 - 9:48:11 PM


  • HAL Id : in2p3-01355004, version 1




A. Ritacco. Polarimetry at millimetre wavelengths with the NIKA and NIKA2 camera. European Week of Astronomy and Space Science (EWASS2016), Jul 2016, Athens, Greece. ⟨in2p3-01355004⟩



Record views