Abstract
The C-Band All-Sky Survey (C-BASS) is a high-sensitivity all-sky radio survey at an angular resolution of 45 arcmin and a frequency of 4.7 GHz. We present a total intensity map of the North Celestial Pole (NCP) region of sky, above declination > +80, which is limited by source confusion at a level of ≈ 0:6mK rms.We apply the template-tting (cross-correlation) technique to WMAP and Planck data, using the C-BASS map as the synchrotron template, to investigate the contribution of diffuse foreground emission at frequencies 20{40 GHz. We quantify the anomalous microwave emission (AME) that is correlated with far-infrared dust emission. The AME amplitude does not change signicantly (< 10 %) when using the higher frequency C-BASS 4.7 GHz template instead of the traditional Haslam 408MHz map as a tracer of synchrotron radiation. We measure template coecients of 9:930:35 and 9:520:34K per unit 353 when using the Haslam and C-BASS synchrotron templates, respectively. The AME contributes 552 K rms at 22.8 GHz and accounts for 60% of the total foreground emission. Our results show that a harder (atter spectrum) component of synchrotron emission is not dominant at frequencies & 5 GHz; the best-tting synchrotron temperature spectral index is = 􀀀2:91 0:04 from 4.7 to 22.8 GHz and = 􀀀2:85 0:14 from 22:8 to 44.1 GHz. Free-free emission is weak, contributing 7 K rms ( 7%) at 22.8 GHz. The best explanation for the AME is still electric dipole emission from small spinning dust grains.
Original language | English |
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Journal | Monthly Notices of the Royal Astronomical Society |
Early online date | 22 Feb 2019 |
DOIs | |
Publication status | Published - 2019 |
Keywords
- surveys { radiation mechanism
- non-thermal { radiation mechanism
- thermal { diuse radiation { radio continuum
- ISM