Astron. Astrophys. 364, 377-390 (2000)

Cluster deprojection combining multiple observable data sets

K. Reblinsky

Max-Planck-Institut für Astrophysik, Postfach 1317, 85741 Garching, Germany (reblinsk@mpa-garching.mpg.de)

Received 8 September 2000 / Accepted 6 October 2000

Abstract

In this paper a general, parameter-free algorithm for the deprojection of observed, two-dimensional cluster images is proposed. The algorithm is based on the Richardson-Lucy algorithm for the rectification of observed distributions, and it combines multiple sets of observable data from clusters of galaxies - weak lensing (lensing potential ), X-ray (X-ray surface brightness ), and Sunyaev-Zel'dovich (temperature decrement ) images - to obtain information on the structure along the line-of-sight, namely the 3-dim. gravitational potential .

For the derivation of this multiple-data Richardson-Lucy deprojection algorithm we specify a geometrical model for the cluster assuming axial symmetry only. We demonstrate the quality of the reconstructions using gas-dynamical simulations assuming an inclination angle for the cluster. The achieved deprojections are shown to yield a stable and unique reconstruction of the 3-dim. structure of the cluster. Strategies for determining the inclination angle and the weight factors used for the reconstruction are discussed. In the end we provide an outlook on the suitability of the algorithm for practical applications to true observational data.

Key words: galaxies: clusters: general cosmology: gravitational lensing cosmology: observations cosmology: dark matter

This article contains no SIMBAD objects.

Contents

• 1. Introduction
• 2. Formalism
  • 2.1. Richardson-Lucy algorithm
  • 2.2. Richardson-Lucy algorithm: the axisymmetric case
• 3. Observables sensitive to the LOS-structure
  • 3.1. Lensing potential
  • 3.2. X-ray emissivity
  • 3.3. Sunyaev-Zel'dovich effect
• 4. Multiple-data Richardson-Lucy deprojection
  • 4.1. Implementation of the multiple-data Richardson-Lucy deprojection
• 5. Deprojection of cluster images from gas-dynamical simulations
• 6. -based determination of inclination angle i
• 7. Discussion
• Acknowledgements
• Appendices
  • A: derivation of the kernel and formulation of the RL-scheme
• References

© European Southern Observatory (ESO) 2000

Online publication: January 29, 2001
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