Astron. Astrophys. 334, 409-419 (1998)
Moving gravitational lenses:
imprints on the cosmic microwave background
N. Aghanim 1,
S. Prunet 1,
O. Forni 1 and
F.R. Bouchet 2
1 IAS-CNRS, Université Paris XI, Bâtiment 121,
F-91405 Orsay Cedex, France
2 IAP-CNRS, 98 bis, Boulevard Arago, F-75014 Paris,
France
Received 4 December 1997 / Accepted 2 March 1998
Abstract
With the new generation of instruments for Cosmic Microwave
Background (CMB) observations aiming at an accuracy level of a few
percent in the measurement of the angular power spectrum of the
anisotropies, the study of the contributions due to secondary effects
has gained impetus. Furthermore, a reinvestigation of the main
secondary effects is crucial in order to predict and quantify their
effects on the CMB and the errors that they induce in the
measurements.
In this paper, we investigate the contribution, to the CMB, of
secondary anisotropies induced by the transverse motions of clusters
of galaxies. This effect is similar to the Kaiser-Stebbins effect. In
order to address this problem, we model the gravitational potential
well of an individual structure using the Navarro, Frenk & White
profile. We generalise the effect of one structure to a population of
objects predicted using the Press-Schechter formalism. We simulate
maps of these secondary fluctuations, compute the angular power
spectrum and derive the average contributions for three cosmological
models. We then investigate a simple method to separate this new
contribution from the primary anisotropies and from the main secondary
effect, the Sunyaev-Zel'dovich kinetic effect from the lensing
clusters.
Key words: galaxies: clusters:
general
cosmic microwave
background
gravitational lensing
Send offprint requests to: N. Aghanim
Contents
© European Southern Observatory (ESO) 1998
Online publication: May 15, 1998
helpdesk@link.springer.de  |