Planck early results. IV. First assessment of the High Frequency Instrument in-flight performance
File(s)
Published version
Author(s)
Type
Journal Article
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.
Date Issued
2011-12-01
Date Acceptance
2011-06-29
Citation
Astronomy and Astrophysics, 2011, 536
ISSN
0004-6361
Publisher
Elsevier
Journal / Book Title
Astronomy and Astrophysics
Volume
536
Copyright Statement
© 2011 ESO.
Sponsor
Science and Technology Facilities Council (STFC)
Science and Technology Facilities Council (STFC)
Science and Technology Facilities Council (STFC)
Science and Technology Facilities Council (STFC)
Science and Technology Facilities Council (STFC)
Science and Technology Facilities Council (STFC)
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000298485100005&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Grant Number
ST/G001901/1
ST/I005765/1
ST/F01239X/1
ST/J004812/1
ST/G003874/1
ST/F012373/1
Subjects
Science & Technology
Physical Sciences
Astronomy & Astrophysics
instrumentation: detectors
methods: data analysis
instrumentation: photometers
cosmic background radiation
cosmology: observations
PRE-LAUNCH STATUS
POWER SPECTRUM
BOOMERANG
HFI
BOLOMETERS
ANISOTROPY
MISSION
SYSTEM
CALIBRATION
CRYOCOOLER
Publication Status
Published
Article Number
A4
Date Publish Online
2011-12-01