Astron. Astrophys. 325, 9-18
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Cosmology with Sunyaev-Zeldovich observations from space
N. Aghanim1, A. De Luca1, F. R. Bouchet2, R. Gispert1, and J. L. Puget1
1IAS-CNRS, Université Paris XI, Bâtiment 121,
F-91405 Orsay Cedex, France
Received 3 July 1996 / Accepted 6 March 1997
In order to assess the potential of future microwave anisotropy space experiments for detecting clusters by their Sunyaev-Zeldovich (SZ) thermal effect, we have simulated maps of the large scale distribution of their Compton parameter y and of the temperature anisotropy induced by their proper motion. Our model is based on a predicted distribution of clusters per unit of redshift and flux density using a Press-Schecter approach (De Luca et al. 1995).
These maps were used to create simulated microwave sky by adding them to the microwave contributions of the emissions of our Galaxy (free-free, dust and synchrotron) and the primary Cosmic Microwave Background (CMB) anisotropies (corresponding to a COBE-normalized standard Cold Dark Model scenario). In order to simulate measurements representative of what current technology should achieve, ``observations'' were performed according to the instrumental characteristics (number of spectral bands, angular resolutions and detector sensitivity) of the COBRAS/SAMBA space mission. These observations were separated into physical components by an extension of the Wiener filtering theory (Bouchet et al. 1996). We then analyzed the resulting y and maps which now include both the primary anisotropies and those superimposed due to cluster motions. A cluster list was obtained from the recovered y maps, and their profiles compared with the input ones. Even for low y-values, the input and output profiles show good agreement, most notably in the outer parts of the profile where values as low as are properly mapped. We also construct and optimize a spatial filter which is used to derive the accuracy on the measurement of the radial peculiar velocity of a detected cluster. We derive the accuracy of the mapping of the very large scale cosmic velocity field obtained from such measurements.
Key words: cosmology: cosmic microwave background - galaxies: clusters
© European Southern Observatory (ESO) 1997