Discriminating between unresolved point sources and "negative" SZ clusters in CMB maps

• Main Authors: Rubiño-Martín, J A, Sunyaev, R A
• Language: English
• Published: 2002
• Subjects: Astrophysics and Astronomy; Lambda; South Pole; South pole
• Online Access: http://cds.cern.ch/record/592327

Clusters of galaxies produce negative features at wavelengths $\lambda > 1.25$ mm in CMB maps, by means of the thermal SZ effect, while point radio sources produce positive peaks. This fact implies that a distribution of unresolved SZ clusters could be detected using the negative asymmetry introduced in the odd-moments of the brightness map (skewness and higher), or in the probability distribution function (PDF) for the fluctuations. This property provides a consistency check to the recent detections from CBI and BIMA experiments of an excess of power at small angular scales, in order to confirm that they are produced by a distribution of unresolved SZ clusters. However it will require at least 1.5 - 2 times more observing time than detection of corresponding power signal. This approach could also be used with the data of the planned SZ experiments (e.g. AMI, AMIBA, APEX, 8 m South Pole telescope).