FASTLens (FAst STatistics for weak Lensing) : Fast method for Weak Lensing Statistics and map making

Details FASTLens (FAst STatistics for weak Lensing) : Fast method for Weak Lensing Statistics and map making FASTLens (FAst STatistics for weak Lensing) : Fast method for Weak Lensing Statistics and map making

2008-04-25

arxiv.org/abs/0804.4068v2

Astronomy and Astrophysics

Astrophysics

Final version accepted by MNRAS. The FASTLens software is available from the following link : http://irfu.cea.fr/Ast/fastlens.

Scientific paper

With increasingly large data sets, weak lensing measurements are able to measure cosmological parameters with ever greater precision. However this increased accuracy also places greater demands on the statistical tools used to extract the available information. To date, the majority of lensing analyses use the two point-statistics of the cosmic shear field. These can either be studied directly using the two-point correlation function, or in Fourier space, using the power spectrum. But analyzing weak lensing data inevitably involves the masking out of regions or example to remove bright stars from the field. Masking out the stars is common practice but the gaps in the data need proper handling. In this paper, we show how an inpainting technique allows us to properly fill in these gaps with only $N \log N$ operations, leading to a new image from which we can compute straight forwardly and with a very good accuracy both the pow er spectrum and the bispectrum. We propose then a new method to compute the bispectrum with a polar FFT algorithm, which has the main advantage of avoiding any interpolation in the Fourier domain. Finally we propose a new method for dark matter mass map reconstruction from shear observations which integrates this new inpainting concept. A range of examples based on 3D N-body simulations illustrates the results.

Affiliated with

Also associated with

No associations

Rating

FASTLens (FAst STatistics for weak Lensing) : Fast method for Weak Lensing Statistics and map making does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with FASTLens (FAst STatistics for weak Lensing) : Fast method for Weak Lensing Statistics and map making, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and FASTLens (FAst STatistics for weak Lensing) : Fast method for Weak Lensing Statistics and map making will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-728111