Observing with NIKA2Pol from the IRAM 30m telescope : Early results on the commissioning phase

¹ Univ. Grenoble Alpes, CNRS, Grenoble INP, LPSC-IN2P3, 53, avenue des Martyrs, 3000 Grenoble, France
² LLR (Laboratoire Leprince-Ringuet), CNRS, École Polytechnique, Institut Polytechnique de Paris, Palaiseau, France
³ Centro de Estudios de Física del Cosmos de Aragón (CEFCA), Plaza San Juan, 1, planta 2, E-44001, Teruel, Spain
⁴ Astronomy Instrumentation Group, University of Cardiff, UK
⁵ AIM, CEA, CNRS, Université Paris-Saclay, Université Paris Diderot, Sorbonne Paris Cité, 91191 Gif-sur-Yvette, France
⁶ Univ. Grenoble Alpes, CNRS, IPAG, 38000 Grenoble, France
⁷ Institut d’Astrophysique Spatiale (IAS), CNRS and Université Paris Sud, Orsay, France
⁸ Institut Néel, CNRS and Université Grenoble Alpes, France
⁹ Dipartimento di Fisica, Sapienza Università di Roma, Piazzale Aldo Moro 5, I-00185 Roma, Italy
¹⁰ Institut de RadioAstronomie Millimétrique (IRAM), Grenoble, France
¹¹ Centro de Astrobiología (CSIC-INTA), Torrejón de Ardoz, 28850 Madrid, Spain
¹² Instituto de Radioastronomía Milimétrica (IRAM), Granada, Spain
¹³ Aix Marseille Univ, CNRS, CNES, LAM (Laboratoire d’Astrophysique de Marseille), Marseille, France
¹⁴ LERMA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMCUniv. Paris 06, 75014 Paris, France
¹⁵ School of Earth and Space Exploration and Department of Physics, Arizona State University, Tempe, AZ 85287
¹⁶ Institut d’Astrophysique de Paris, CNRS (UMR7095), 98 bis boulevard Arago, 75014 Paris, France
¹⁷ Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
¹⁸ Department of Physics and Astronomy, Graduate School of Science and Engineering, KagoshimaUniversity, 1-21-35 Korimoto, Kagoshima, Kagoshima 890-0065, Japan
¹⁹ National Astronomical Observatory of Japan, Osawa 2-21-1, Mitaka, Tokyo 181-8588, Japan

^* e-mail: alessia.ritacco@ias.u-psud.fr

Published online: 27 January 2020

Abstract

The NIKA2 polarization channel at 260 GHz (1.15 mm) has been proposed primarily to observe galactic star-forming regions and probe the critical scales between 0.01-0.05 pc at which magnetic field lines may channel the matter of interstellar filaments into growing dense cores. The NIKA2 polarime-ter consists of a room temperature continuously rotating multi-mesh HWP and a cold polarizer that separates the two orthogonal polarizations onto two 260 GHz KIDs arrays. We describe in this paper the preliminary results obtained during the most recent commissioning campaign performed in December 2018. We concentrate here on the analysis of the extended sources, while the observation of compact sources is presented in a companion paper [12]. We present preliminary NIKA2 polarization maps of the Crab nebula. We find that the integrated polarization intensity flux measured by NIKA2 is consistent with expectations. In terms of polarization angle, we are still limited by systematic uncertainties that will be further investigated in the forthcoming commissioning campaigns.