scholarly journals Planck2018 results

2020 ◽  
Vol 641 ◽  
pp. A3 ◽  
Author(s):  
◽  
N. Aghanim ◽  
Y. Akrami ◽  
M. Ashdown ◽  
J. Aumont ◽  
...  
Keyword(s):  
High Frequency ◽  
Major Change ◽  
Systematic Effect ◽  
Microwave Background ◽  
Extensive Analysis ◽  
Systematic Effects ◽  
Single Detector ◽  
End To End ◽  
Frequency Calibration ◽  
Analogue To Digital

This paper presents the High Frequency Instrument (HFI) data processing procedures for thePlanck2018 release. Major improvements in mapmaking have been achieved since the previousPlanck2015 release, many of which were used and described already in an intermediate paper dedicated to thePlanckpolarized data at low multipoles. These improvements enabled the first significant measurement of the reionization optical depth parameter usingPlanck-HFI data. This paper presents an extensive analysis of systematic effects, including the use of end-to-end simulations to facilitate their removal and characterize the residuals. The polarized data, which presented a number of known problems in the 2015Planckrelease, are very significantly improved, especially the leakage from intensity to polarization. Calibration, based on the cosmic microwave background (CMB) dipole, is now extremely accurate and in the frequency range 100–353 GHz reduces intensity-to-polarization leakage caused by calibration mismatch. The Solar dipole direction has been determined in the three lowest HFI frequency channels to within one arc minute, and its amplitude has an absolute uncertainty smaller than 0.35μK, an accuracy of order 10−4. This is a major legacy from thePlanckHFI for future CMB experiments. The removal of bandpass leakage has been improved for the main high-frequency foregrounds by extracting the bandpass-mismatch coefficients for each detector as part of the mapmaking process; these values in turn improve the intensity maps. This is a major change in the philosophy of “frequency maps”, which are now computed from single detector data, all adjusted to the same average bandpass response for the main foregrounds. End-to-end simulations have been shown to reproduce very well the relative gain calibration of detectors, as well as drifts within a frequency induced by the residuals of the main systematic effect (analogue-to-digital convertor non-linearity residuals). Using these simulations, we have been able to measure and correct the small frequency calibration bias induced by this systematic effect at the 10−4level. There is no detectable sign of a residual calibration bias between the first and second acoustic peaks in the CMB channels, at the 10−3level.

scholarly journals Optimal strategy for polarization modulation in the LSPE-SWIPE experiment

2018 ◽  
Vol 609 ◽  
pp. A52 ◽  
Author(s):  
A. Buzzelli ◽  
P. de Bernardis ◽  
S. Masi ◽  
N. Vittorio ◽  
G. de Gasperis
Keyword(s):  
Power Spectrum ◽  
Polarization Modulation ◽  
Microwave Background ◽  
Angular Power Spectrum ◽  
Half Wave ◽  
Wide Range ◽  
Cmb Polarization ◽  
Systematic Effects ◽  
Single Detector ◽  
Frequency Map

Context. Cosmic microwave background (CMB) B-mode experiments are required to control systematic effects with an unprecedented level of accuracy. Polarization modulation by a half wave plate (HWP) is a powerful technique able to mitigate a large number of the instrumental systematics. Aims. Our goal is to optimize the polarization modulation strategy of the upcoming LSPE-SWIPE balloon-borne experiment, devoted to the accurate measurement of CMB polarization at large angular scales. Methods. We departed from the nominal LSPE-SWIPE modulation strategy (HWP stepped every 60 s with a telescope scanning at around 12 deg/s) and performed a thorough investigation of a wide range of possible HWP schemes (either in stepped or continuously spinning mode and at different azimuth telescope scan-speeds) in the frequency, map and angular power spectrum domain. In addition, we probed the effect of high-pass and band-pass filters of the data stream and explored the HWP response in the minimal case of one detector for one operation day (critical for the single-detector calibration process). We finally tested the modulation performance against typical HWP-induced systematics. Results. Our analysis shows that some stepped HWP schemes, either slowly rotating or combined with slow telescope modulations, represent poor choices. Moreover, our results point out that the nominal configuration may not be the most convenient choice. While a large class of spinning designs provides comparable results in terms of pixel angle coverage, map-making residuals and BB power spectrum standard deviations with respect to the nominal strategy, we find that some specific configurations (e.g., a rapidly spinning HWP with a slow gondola modulation) allow a more efficient polarization recovery in more general real-case situations. Conclusions. Although our simulations are specific to the LSPE-SWIPE mission, the general outcomes of our analysis can be easily generalized to other CMB polarization experiments.

scholarly journals SRoll2: an improved mapmaking approach to reduce large-scale systematic effects in the Planck High Frequency Instrument legacy maps

2019 ◽  
Vol 629 ◽  
pp. A38 ◽  
Author(s):  
J.-M. Delouis ◽  
L. Pagano ◽  
S. Mottet ◽  
J.-L. Puget ◽  
L. Vibert
Keyword(s):  
High Frequency ◽  
Large Scale ◽  
Order Effect ◽  
Order Effects ◽  
Model Parameters ◽  
Systematic Effect ◽  
Analog To Digital ◽  
Systematic Effects ◽  
The One ◽  
Higher Order Effects

This paper describes an improved map making approach with respect to the one used for the Planck High Frequency Instrument 2018 Legacy release. The algorithm SRoll2 better corrects the known instrumental effects that still affected mostly the polarized large-angular-scale data by distorting the signal, and/or leaving residuals observable in null tests. The main systematic effect is the nonlinear response of the onboard analog-to-digital convertors that was cleaned in the Planck HFI Legacy release as an empirical time-varying linear detector chain response which is the first-order effect. The SRoll2 method fits the model parameters for higher-order effects and corrects the full distortion of the signal. The model parameters are fitted using the redundancies in the data by iteratively comparing the data and a model. The polarization efficiency uncertainties and associated errors have also been corrected based on the redundancies in the data and their residual levels characterized with simulations. This paper demonstrates the effectiveness of the method using end-to-end simulations, and provides a measure of the systematic effect residuals that now fall well below the detector noise level. Finally, this paper describes and characterizes the resulting SRoll2 frequency maps using the associated simulations that are released to the community.

scholarly journals NATURAL INFLATION, PLANCK SCALE PHYSICS AND OSCILLATING PRIMORDIAL SPECTRUM

2005 ◽  
Vol 14 (08) ◽  
pp. 1347-1364 ◽  
Author(s):  
XIULIAN WANG ◽  
BO FENG ◽  
MINGZHE LI ◽  
XUE-LEI CHEN ◽  
XINMIN ZHANG
Keyword(s):  
Power Spectrum ◽  
Cosmic Microwave Background ◽  
High Frequency ◽  
Large Scale ◽  
Planck Scale ◽  
Microwave Background ◽  
Precision Data ◽  
Inflation Model ◽  
High Precision Data ◽  
Planck Scale Physics

In the "natural inflation" model, the inflaton potential is periodic. We show that Planck scale physics may induce corrections to the inflaton potential, which is also periodic with a greater frequency. Such high frequency corrections produce oscillating features in the primordial fluctuation power spectrum, which are not entirely excluded by the current observations and may be detectable in high precision data of cosmic microwave background (CMB) anisotropy and large scale structure (LSS) observations.

scholarly journals The MAP Satellite Mission to Map the CMB Anisotropy

2005 ◽  
Vol 201 ◽  
pp. 75-85
Author(s):  
Lyman. Page
Keyword(s):  
Cosmic Microwave Background ◽  
Design Principle ◽  
Instrument Design ◽  
Deep Space ◽  
Microwave Background ◽  
Satellite Mission ◽  
Mapping Strategy ◽  
Systematic Effects ◽  
Error Bars

The Microwave Anisotropy Probe (MAP) satellite is scheduled to launch in mid-2001. MAP's goal is to produce a map of the anisotropy in the cosmic microwave background of unprecedented accuracy and precision. The guiding design principle has been the minimization of systematic effects. The instrument design and mapping strategy work in concert to take advantage of the unique opportunities afforded by deep space. We give an overview of the mission and compare the projected MAP error bars to recent measurements.

scholarly journals AMIBA: FIRST-YEAR RESULTS FOR SUNYAEV-ZEL'DOVICH EFFECT

2008 ◽  
Vol 23 (17n20) ◽  
pp. 1675-1686 ◽  
Author(s):  
JIUN-HUEI PROTY WU ◽  
TZI-HONG CHIUEH ◽  
CHI-WEI HUANG ◽  
YAO-WEI LIAO ◽  
FU-CHENG WANG ◽  
...  
Keyword(s):  
Cosmic Microwave Background ◽  
Galaxy Clusters ◽  
First Year ◽  
Microwave Background ◽  
Expansion Plan ◽  
Sunyaev Zel'dovich Effect ◽  
Systematic Effects ◽  
Science Operation

We discuss the observation, analysis, and results of the first-year science operation of AMiBA, an interferometric experiment designed to study cosmology via the measurement of Cosmic Microwave Background (CMB). In 2007, we successfully observed 6 galaxy clusters (z < 0.33) through the Sunyaev-Zel'dovich effect. AMiBA is the first CMB interferometer operating at 86–102 GHz, currently with 7 close-packed antennas of 60 cm in diameter giving a synthesized resolution of around 6 arcminutes. An observing strategy with on-off-source modulation is used to remove the effects from electronic offset and ground pickup. Formalism of the analysis is given and preliminary science results are summarized. Tests for systematic effects are also addressed. We also discuss the expansion plan.

scholarly journals Studies of Systematic Limitations in the EDM Searches at Storage Rings

2016 ◽  
Vol 40 ◽  
pp. 1660093 ◽  
Author(s):  
Artem Saleev ◽  
Nikolai Nikolaev ◽  
Frank Rathmann
Keyword(s):  
Dipole Moment ◽  
Magnetic Dipole ◽  
Electric Dipole Moment ◽  
Electric Dipole ◽  
Magnetic Dipole Moment ◽  
Original Method ◽  
Spin Rotation ◽  
Systematic Effect ◽  
Systematic Effects ◽  
Magnetic Ring

Searches of the electric dipole moment (EDM) at a pure magnetic ring, like COSY, encounter strong background coming from magnetic dipole moment (MDM). The most troubling issue is the MDM spin rotation in the so-called imperfection, radial and longitudinal, B-fields. To study the systematic effects of the imperfection fields at COSY we proposed the original method which makes use of the two static solenoids acting as artificial imperfections. Perturbation of the spin tune caused by the spin kicks in the solenoids probes the systematic effect of cumulative spin rotation in the imperfection fields all over the ring. The spin tune is one of the most precise quantities measured presently at COSY at [Formula: see text] level. The method has been successfully tested in September 2014 run at COSY, unravelling strength of spin kicks in the ring’s imperfection fields at the level of [Formula: see text].

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