Issue |
A&A
Volume 396, Number 2, December III 2002
|
|
---|---|---|
Page(s) | 411 - 418 | |
Section | Astrophysical processes | |
DOI | https://doi.org/10.1051/0004-6361:20021372 | |
Published online | 03 December 2002 |
Suppressing the contribution of intrinsic galaxy alignments to the shear two-point correlation function
Institut für Astrophysik und Extraterrestrische Forschung, Universität Bonn, Auf dem Hügel 71, 53121 Bonn, Germany
Corresponding author: L. King, lindsay@astro.uni-bonn.de
Received:
13
August
2002
Accepted:
January
1900
Cosmological weak lensing gives rise to correlations in the
ellipticities of faint galaxies. This cosmic shear signal depends upon
the matter power spectrum, thus providing a means to constrain
cosmological parameters. It has recently been proposed that
intrinsic alignments arising at the epoch of galaxy formation can
also contribute significantly to the observed correlations, the
amplitude increasing with decreasing survey depth. Here we consider
the two-point shear correlation function, and demonstrate that
photometric redshift information can be used to suppress the intrinsic
signal; at the same time Poisson noise is increased, due to a decrease
in the effective number of galaxy pairs. The choice to apply such a
redshift-depending weighting will depend on the characteristics of the
survey in question. In surveys with , although the
lensing signal dominates, the measurement error bars may soon become
smaller than the intrinsic alignment signal; hence, in order not to
be dominated by systematics, redshift information in cosmic shear
statistics will become a necessity. We discuss various aspects of
this.
Key words: cosmology: dark matter / cosmology: gravitational lensing
© ESO, 2002
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.