First results from the Very Small Array -- III. The cosmic microwave background power spectrum

Abstract

We present the power spectrum of the fluctuations in the cosmic microwave background detected by the Very Small Array (VSA) in its first season of observations in its compact configuration. We find clear detections of first and second acoustic peaks at l≈ 200 and ≈550, plus detection of power on scales up to l= 800. The VSA power spectrum is in very good agreement with the results of the BOOMERanG, DASI and MAXIMA telescopes despite the differing potential systematic errors.