Planck early results. IV. First assessment of the High Frequency Instrument in-flight performance^⋆

¹ Astroparticule et Cosmologie, CNRS (UMR 7164), Université Denis Diderot Paris 7, Bâtiment Condorcet, 10 rue A. Domon et Léonie Duquet, Paris, France
² Astrophysics Group, Cavendish Laboratory, University of Cambridge, J J Thomson Avenue, Cambridge CB3 0HE, UK
³ Atacama Large Millimeter/submillimeter Array, ALMA Santiago Central Offices, Alonso de Cordova 3107, Vitacura, Casilla 763 0355, Santiago, Chile
⁴ CITA, University of Toronto, 60 St. George St., Toronto, ON M5S 3H8, Canada
⁵ CNES, 18 avenue Édouard Belin, 31401 Toulouse Cedex 9, France
⁶ CNRS, IRAP, 9 Av. colonel Roche, BP 44346, 31028 Toulouse Cedex 4, France
⁷ California Institute of Technology, Pasadena, California, USA
⁸ DAMTP, University of Cambridge, Centre for Mathematical Sciences, Wilberforce Road, Cambridge CB3 0WA, UK
⁹ DSM/Irfu/SPP, CEA-Saclay, 91191 Gif-sur-Yvette Cedex, France
¹⁰ DTU Space, National Space Institute, Juliane Mariesvej 30, Copenhagen, Denmark
¹¹ Department of Astronomy and Astrophysics, University of Toronto, 50 Saint George Street, Toronto, Ontario, Canada
¹² Department of Physics, Princeton University, Princeton, New Jersey, USA
¹³ Department of Physics, University of California, One Shields Avenue, Davis, California, USA
¹⁴ Department of Physics, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, Illinois, USA
¹⁵ Dipartimento di Fisica, Università La Sapienza, P. le A. Moro 2, Roma, Italy
¹⁶ Dipartimento di Fisica, Università degli Studi di Milano, via Celoria, 16, Milano, Italy
¹⁷ European Southern Observatory, ESO Vitacura, Alonso de Cordova 3107, Vitacura, Casilla 19001, Santiago, Chile
¹⁸ European Space Agency, ESTEC, Keplerlaan 1, 2201 AZ Noordwijk, The Netherlands
¹⁹ INAF – Osservatorio Astronomico di Trieste, via G.B. Tiepolo 11, Trieste, Italy
²⁰ INAF/IASF Bologna, via Gobetti 101, Bologna, Italy
²¹ INAF/IASF Milano, via E. Bassini 15, Milano, Italy
²² INSU, Institut des sciences de l’univers, CNRS, 3 rue Michel-Ange, 75794 Paris Cedex 16, France
²³ IPAG: Institut de Planétologie et d’Astrophysique de Grenoble, Université Joseph Fourier, Grenoble 1/CNRS-INSU, UMR 5274, 38041 Grenoble, France
²⁴ Imperial College London, Astrophysics group, Blackett Laboratory, Prince Consort Road, London, SW7 2AZ, UK
²⁵ Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125, USA
²⁶ Institut Néel, CNRS, Université Joseph Fourier Grenoble I, 25 rue des Martyrs, Grenoble, France
²⁷ Institut d’Astrophysique Spatiale, CNRS (UMR8617) Université Paris-Sud 11, Bâtiment 121, Orsay, France
²⁸ Institut d’Astrophysique de Paris, CNRS UMR7095, Université Pierre & Marie Curie, 98bis boulevard Arago, Paris, France
²⁹ Institut de Ciències de l’Espai, CSIC/IEEC, Facultat de Ciències, Campus UAB, Torre C5 par-2, Bellaterra 08193, Spain
³⁰ Institut de Radioastronomie Millimétrique (IRAM), Avenida Divina Pastora 7, Local 20, 18012 Granada, Spain
³¹ Institut de Radioastronomie Millimétrique (IRAM),Domaine Universitaire de Grenoble, 300 rue de la Piscine, 38406 Grenoble, France
³² Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK
³³ Instituto de Astrofísica de Canarias, C/Vía Láctea s/n, La Laguna, Tenerife, Spain
³⁴ Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California, USA
³⁵ Jodrell Bank Centre for Astrophysics, Alan Turing Building, School of Physics and Astronomy, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
³⁶ Kavli Institute for Cosmology Cambridge, Madingley Road, Cambridge, CB3 0HA, UK
³⁷ LERMA, CNRS, Observatoire de Paris, 61 avenue de l’Observatoire, Paris, France
³⁸ Laboratoire AIM, IRFU/Service d’Astrophysique – CEA/DSM – CNRS – Université Paris Diderot, Bât. 709, CEA-Saclay, 91191 Gif-sur-Yvette Cedex, France
³⁹ Laboratoire Traitement et Communication de l’Information, CNRS (UMR 5141) and Télécom ParisTech, 46 rue Barrault, 75634 Paris Cedex 13, France
⁴⁰ Laboratoire d’Astrophysique de Marseille, 38 rue Frédéric Joliot-Curie, 13388, Marseille Cedex 13, France
⁴¹ Laboratoire de Physique Subatomique et de Cosmologie, CNRS/IN2P3, Université Joseph Fourier Grenoble I, Institut National Polytechnique de Grenoble, 53 rue des Martyrs, 38026 Grenoble Cedex, France
⁴² Laboratoire de l’Accélérateur Linéaire, Université Paris-Sud 11, CNRS/IN2P3, Orsay, France
⁴³ Lawrence Berkeley National Laboratory, Berkeley, California, USA
⁴⁴ Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, 85741 Garching, Germany
⁴⁵ National University of Ireland, Department of Experimental Physics, Maynooth, Co. Kildare, Ireland
⁴⁶ Observational Cosmology, Mail Stop 367-17, California Institute of Technology, Pasadena, CA, 91125, USA
⁴⁷ Optical Science Laboratory, University College London, Gower Street, London, UK
⁴⁸ Rutherford Appleton Laboratory, Chilton, Didcot, UK
⁴⁹ SUPA, Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UK
⁵⁰ School of Physics and Astronomy, Cardiff University, Queens Buildings, The Parade, Cardiff, CF24 3AA, UK
⁵¹ Space Research Institute (IKI), Russian Academy of Sciences, Profsoyuznaya Str, 84/32, Moscow 117997, Russia
⁵² Space Sciences Laboratory, University of California, Berkeley, California, USA
⁵³ Stanford University, Dept of Physics, Varian Physics Bldg, 382 via Pueblo Mall, Stanford, California, USA
⁵⁴ Universität Heidelberg, Institut für Theoretische Astrophysik, Albert-Überle-Str. 2, 69120 Heidelberg, Germany
⁵⁵ Université de Toulouse, UPS-OMP, IRAP, 31028 Toulouse Cedex 4, France
⁵⁶ Universities Space Research Association, Stratospheric Observatory for Infrared Astronomy, MS 211-3, Moffett Field, CA 94035, USA
⁵⁷ University of Granada, Departamento de Física Teórica y del Cosmos, Facultad de Ciencias, Granada, Spain
⁵⁸ University of Miami, Knight Physics Building, 1320 Campo Sano Dr., Coral Gables, Florida, USA
⁵⁹ Warsaw University Observatory, Aleje Ujazdowskie 4, 00-478 Warszawa, Poland

Received: 10 January 2011
Accepted: 29 June 2011

Abstract

The Planck High Frequency Instrument (HFI) is designed to measure the temperature and polarization anisotropies of the cosmic microwave background and Galactic foregrounds in six  ~30% bands centered at 100, 143, 217, 353, 545, and 857 GHz at an angular resolution of 10′ (100 GHz), 7′ (143 GHz), and 5′ (217 GHz and higher). HFI has been operating flawlessly since launch on 14 May 2009, with the bolometers reaching 100 mK the first week of July. The settings of the readout electronics, including bolometer bias currents, that optimize HFI’s noise performance on orbit are nearly the same as the ones chosen during ground testing. Observations of Mars, Jupiter, and Saturn have confirmed that the optical beams and the time responses of the detection chains are in good agreement with the predictions of physical optics modeling and pre-launch measurements. The Detectors suffer from a high flux of cosmic rays due to historically low levels of solar activity. As a result of the redundancy of Planck’s observation strategy, theremoval of a few percent of data contaminated by glitches does not significantly affect the instrumental sensitivity. The cosmic ray flux represents a significant and variable heat load on the sub-Kelvin stage. Temporal variation and the inhomogeneous distribution of the flux results in thermal fluctuations that are a probable source of low frequency noise. The removal of systematic effects in the time ordered data provides a signal with an average noise equivalent power that is 70% of the goal in the 0.6−2.5 Hz range. This is slightly higher than was achieved during the pre-launch characterization but better than predicted in the early phases of the project. The improvement over the goal is a result of the low level of instrumental background loading achieved by the optical and thermal design of the HFI.