SECOND SEASON QUIET OBSERVATIONS: MEASUREMENTS OF THE COSMIC MICROWAVE BACKGROUND POLARIZATION POWER SPECTRUM AT 95 GHz

Abstract

The Q/U Imaging ExperimenT (QUIET) has observed the cosmic microwave background (CMB) at 43 and 95 GHz. The 43 GHz results have been published in a previous paper, and here we report the measurement of CMB polarization power spectra using the 95 GHz data. This data set comprises 5337 hr of observations recorded by an array of 84 polarized coherent receivers with a total array sensitivity of 87 μK √ s. Four low-foreground fields were observed, covering a total of ∼1000 deg 2 with an effective angular resolution of 12. 8, allowing for constraints on primordial gravitational waves and high signal-to-noise measurements of the E-modes across three acoustic peaks. The data reduction was performed using two independent analysis pipelines, one based on a pseudo-C (PCL) cross-correlation approach, and the other on a maximum-likelihood (ML) approach. All data selection criteria and filters were modified until a predefined set of null tests had been satisfied before inspecting any non-null power spectrum. The results derived by the two pipelines are in good agreement. We characterize the EE, EB, and BB power spectra between = 25 and 975 and find that the EE spectrum is consistent with ΛCDM, while the BB power spectrum is consistent with zero. Based on these measurements, we constrain the tensor-to-scalar ratio to r = 1.1 +0.9 −0.8 (r < 2.8 at 95% C.L.) as derived by the ML pipeline, and r = 1.2 +0.9 −0.8 (r < 2.7 at 95% C.L.) as derived by the PCL pipeline. In one of the fields, we find a correlation with the dust component of the Planck Sky Model, though the corresponding excess power is small compared to statistical errors. Finally, we derive limits on all known systematic errors, and demonstrate that these correspond to a tensor-to-scalar ratio smaller than r = 0.01, the lowest level yet reported in the literature.

Testing CPT Symmetry With Current and Future CMB Measurements

“…And we impose priors on these four systematic errors: (8) and marginalize over them to constrain the rotation angle. For the QUIET experiment, since they already provided the systematic errors of EB power spectrum, we directly include this information into our analysis (Araujo et al 2012). In Figure 1 we present current constraints onᾱ from the WMAP9, B03, BICEP1, QUaD and QUIET CMB polarization power spectra with CMB systematic errors.…”

“…Another CMB experiment, the Q/U Imaging ExperimenT (QUIET) (Araujo et al 2012), also published the CMB polarization power spectra at 95 GHz with the EB power spectrum. Furthermore, the nine-year WMAP (WMAP9) (Hinshaw et al 2013), BOOMERanG 2003 (B03) (Montory et al 2006;Jones et al 2006;Piacentini et al 2006) and QUaD (Hinderks et al 2009) also provided the TB and EB polarization power spectra.…”

“…Using two pipelines to analyze the data, they characterized the EB power spectrum between ℓ = 25 and 975 and gave the total systematic error in the EB power spectrum (Araujo et al 2012). …”

Planck2015 results

“…Over the last decade, CMB intensity (temperature) has been augmented by linear polarization data (e.g., Kovac et al 2002;Kogut et al 2003;Sievers et al 2007;Dunkley et al 2009;Pryke et al 2009;Araujo et al 2012;Polarbear Collaboration 2014). Because linear polarization is given by both an amplitude and direction, it can, in turn, be decomposed into two coordinate-independent quantities, each with a different dependence on the cosmology (e.g., Seljak 1997;Kamionkowski et al 1997;Zaldarriaga & Seljak 1997).…”

Including birefringence into time evolution of CMB: Current and future constraints

“…Together with the increased sensitivity in temperature anisotropies, other CMB experiment were designed in order to measure the CMB photons polarization properties, such as WMAP [3], QUIET [4] and BICEP [5,6,7]. Upcoming surveys are now designed to achieve even more precise measurements of E-modes and to finally detect the parity-odd modes (B modes) of CMB polarization (see e.g.…”