Volume 543, July 2012
|Number of page(s)||16|
|Section||Cosmology (including clusters of galaxies)|
|Published online||22 June 2012|
Retrieving the three-dimensional matter power spectrum and galaxy biasing parameters from lensing tomography
Argelander-Institut für Astronomie, Universität Bonn, Auf dem Hügel 71, 53121 Bonn, Germany
Received: 7 October 2011
Accepted: 19 February 2012
Aims. With the availability of galaxy distance indicators in weak lensing surveys, lensing tomography can be harnessed to constrain the three-dimensional (3D) matter power spectrum over a range of redshift and physical scale. By combining galaxy-galaxy lensing and galaxy clustering, this can be extended to probe the 3D galaxy-matter and galaxy-galaxy power spectrum or, alternatively, galaxy biasing parameters.
Methods. To achieve this aim, this paper introduces and discusses minimum variance estimators and a more general Bayesian approach to statistically invert a set of noisy tomography two-point correlation functions, measured within a confined opening angle. Both methods are constructed such that they probe deviations of the power spectrum from a fiducial power spectrum, thereby enabling both a direct comparison of theory and data, and in principle the identification of the physical scale and redshift of deviations. By devising a new Monte Carlo technique, we quantify the measurement noise in the correlators for a fiducial survey, and test the performance of the inversion techniques.
Results. For a relatively deep 200 deg2 survey ( ~ 0.9) with 30 sources per square arcmin, the matter power spectrum can be probed with 3−6σ significance on comoving scales 1 ≲ k h-1 Mpc ≲ 10 and z ≲ 0.3. For 3 lenses per square arcmin, a significant detection (~10σ) of the galaxy-matter power spectrum and galaxy power spectrum is attainable to relatively high redshifts (z ≲ 0.8) and over a wider k-range. Within the Bayesian framework, all three power spectra are easily combined to provide constraints on 3D galaxy biasing parameters. Therein, weak priors on the galaxy bias improve constraints on the matter power spectrum.
Conclusions. A shear tomography analysis of weak-lensing surveys in the near future promises fruitful insights into both the effect of baryons on the nonlinear matter power spectrum at z ≲ 0.3 and galaxy biasing (z ≲ 0.5). However, a proper treatment of the anticipated systematics, which are not included in the mock analysis but discussed here, is likely to reduce the signal-to-noise ratio in the analysis such that a robust assessment of the 3D matter power spectrum probably requires a survey area of at least ~103 deg2. To investigate the matter power spectrum at redshift higher than ~0.3, an increase in survey area is mandatory.
Key words: methods: data analysis / large-scale structure of Universe / dark matter
© ESO, 2012
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.