QUIJOTE scientific results - IV. A northern sky survey in intensity and polarization at 10-20-GHz with the multifrequency instrument

Abstract

We present QUIJOTE intensity and polarization maps in four frequency bands centred around 11, 13, 17, and 19-GHz, and covering approximately 29?000?deg2, including most of the northern sky region. These maps result from 9000?h of observations taken between May 2013 and June 2018 with the first QUIJOTE multifrequency instrument (MFI), and have angular resolutions of around 1°, and sensitivities in polarization within the range 35?40?µK per 1° beam, being a factor ?2?4 worse in intensity. We discuss the data processing pipeline employed, and the basic characteristics of the maps in terms of real space statistics and angular power spectra. A number of validation tests have been applied to characterize the accuracy of the calibration and the residual level of systematic effects, finding a conservative overall calibration uncertainty of 5 per?cent. We also discuss flux densities for four bright celestial sources (Tau A, Cas A, Cyg A, and 3C274), which are often used as calibrators at microwave frequencies. The polarization signal in our maps is dominated by synchrotron emission. The distribution of spectral index values between the 11?GHz and WMAP 23?GHz map peaks at [Beta] = -3.09 with a standard deviation of 0.14. The measured BB/EE ratio at scales of [L lower case+ = 80 is 0.26 ± 0.07 for a Galactic cut |b| > 10°. We find a positive TE correlation for 11?GHz at large angular scales ([L lower case+ [less than or equivalent to] 50), while the EB and TB signals are consistent with zero in the multipole range 30 [less than or equivalent to] [L lower case+ [less than or equivalent to] 150. The maps discussed in this paper are publicly available.