Showing papers by "Peter A. R. Ade published in 1987"

A search for the Sunyaev–Zeldovich effect at millimetre wavelengths

Abstract: The Sunyaev–Zeldovich effect is potentially a powerful tool for observational cosmology. We report the results of the first attempt to detect this small effect at a wavelength of 1.15 mm. At this wavelength the effect has a sign opposite to that at the longer wavelengths previously employed in such studies. Observational data on two clusters, 0016+ 16 and Abell 478, are described. Particular attention has been devoted to the position-dependent offsets which are characteristic of these observations. We analyse the spurious systematic contribution such an offset adds to the Sunyaev–Zeldovich signal, and we demonstrate that, provided that chopping and nodding are performed in hour angle, this contribution can be precisely measured from the baseline drift. These analytical techniques have been applied to 16 hr of observational data on these two clusters. We achieved a marginal detection of the effect corresponding to a temperature decrement in the Rayleigh–Jeans region of ΔTRJ=−1.6±1.0mK for the cluster 0016+16 and an upper limit of ΔTRJ=−0.2±1.0mK for the cluster Abell 478.