Journal
ASTRONOMY & ASTROPHYSICS
Volume 442, Issue 1, Pages 43-U5Publisher
EDP SCIENCES S A
DOI: 10.1051/0004-6361:20053339
Keywords
gravitational lensing; galaxies clusters : general
Categories
Ask authors/readers for more resources
Application of the aperture mass (M-ap-) statistics provides a weak lensing method for the detection of cluster-sized dark matter halos. We present a new aperture filter function and maximise the effectiveness of the M-ap-statistics to detect cluster-sized halos using analytical models. We then use weak lensing mock catalogues generated from ray-tracing through N-body simulations, to analyse the effect of image treatment on the expected number density of halos. Using the Map- statistics, the aperture radius is typically several arcminutes, hence the aperture often lies partly outside a data field, consequently the signal-to-noise ratio of a halo detection decreases. We study these border effects analytically and by using mock catalogues. We find that the expected number density of halos decreases by a factor of two if the size of a field is comparable to the diameter of the aperture used. We finally report on the results of a weak lensing cluster search applying the M-ap- statistics to 50 randomly selected fields which were observed with FORS1 at the VLT. Altogether the 50 VLT fields cover an area of 0.64 square degrees. The I-band images were taken under excellent seeing conditions (average seeing approximate to 0.'' 6) which results in a high number density of galaxies used for the weak lensing analysis (n approximate to 26 arcmin(-2)). In five of the VLT fields, we detect a significant Map- signal which coincides with an overdensity of the light distribution. These detections are thus excellent candidates for shear-selected clusters.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available