Planck performance parameters determined from flight data.
|mean beamc||sensitivity||calibratione||faintest sourcef|
|ν center b||uncertainty||in ERCSC |b| > 30°|
|channel||N detectors a||[GHz]||FWHM||ellipticity||[μKRJs1/ 2]||[μKCMBs1/ 2]||[%]||[mJy]|
|30 GHz .........||4||28.5||32.65||1.38||143.4||146.8||1||480|
|44 GHz .........||6||44.1||27.92||1.26||164.7||173.1||1||585|
|70 GHz .........||12||70.3||13.01||1.27||134.7||152.6||1||481|
|100 GHz .........||8||100||9.37||1.18||17.3||22.6||2||344|
|143 GHz .........||11||143||7.04||1.03||8.6||14.5||2||206|
|217 GHz .........||12||217||4.68||1.14||6.8||20.6||2||183|
|353 GHz .........||12||353||4.43||1.09||5.5||77.3||2||198|
|545 GHz .........||3||545||3.80||1.25||4.9||...||7||381|
|857 GHz .........||3||857||3.67||1.03||2.1||...||7||655|
For 30, 44, and 70 GHz, each “detector” is a linearly polarised radiometer. There are two (orthogonally polarized) radiometers behind each horn. Each radiometer has two diodes, both switched at high frequency between the sky and a blackbody load at ~4 K (Mennella et al. 2011). For 100 GHz and above, each “detector” is a bolometer (Planck HFI Core Team 2011a). Most of the bolometers are sensitive to polarisation, in which case there are two orthogonally polarised detectors behind each horn; some of the detectors are spider-web bolometers (one per horn) sensitive to the total incident power.
Mean optical properties of the N beams at each frequency; FWHM ≡ FWHM of circular Gaussian with the same volume. Ellipticity gives the ratio of major axis to minor axis for a best-fit elliptical Gaussian. In the case of HFI, the mean values quoted are the result of averaging the values of total-power and polarisation-sensitive bolometers, weighted by the number of channels and after removal of those affected by random telegraphic noise. The actual point spread function of an unresolved object on the sky depends not only on the optical properties of the beam, but also on sampling and time domain filtering in signal processing, and the way the sky is scanned. For details on these aspects see Sect. 4 of Mennella et al. (2011), Sect. 4 of Zacchei et al. (2011), Sect. 4.2 of Planck HFI Core Team (2011a), and Sect. 6.2 of Planck HFI Core Team (2011b).
Uncorrelated noise on the sky in 1s for the array of N detectors, in Rayleigh-Jeans units and in thermodynamic CMB units. For a preliminary discussion of correlated noise and systematic effects, see Mennella et al. (2011), Planck HFI Core Team (2011a), Zacchei et al. (2011), and Planck HFI Core Team (2011b).
Flux density of the faintest source included in the ERCSC (Planck Collaboration 2011c).
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.