Weak lensing goes bananas: what flexion really measures
نویسندگان
چکیده
منابع مشابه
A New Measure for Weak Lensing Flexion
We study a possibility to use the octopole moment of gravitationally lensed images as a direct measure of the third-order weak gravitational lensing effect, or the gravitational flexion. It turns out that there is a natural relation between flexion and certain combinations of octopole/higher-multipole moments which we call the Higher Order Lensing Image’s Characteristics (HOLICs). This will all...
متن کاملGalaxy-galaxy Flexion: Weak Lensing to Second Order
In this paper, we develop a new gravitational lensing inversion technique. While traditional approaches assume that the lensing field varies little across a galaxy image, we note that this variation in the field can give rise to a “Flexion” or bending of a galaxy image, which may then be used to detect a lensing signal with increased signal to noise. Since the significance of the Flexion signal...
متن کاملWeak Lensing
In the preceding chapters, the effects of lensing were so strong as to leave an unmistakable imprint on a specific source, allowing a detailed treatment. However, only the densest regions of the universe are able to provide such a spectacular lensing effect. To study more representative regions of the universe, we must examine large numbers of sources statistically. This is the domain of weak l...
متن کاملA Method for Weak Lensing Flexion Analysis by the Holics Moment Approach
We have developed a method for measuring higher-order weak lensing distortions of faint background galaxies, namely the weak gravitational flexion, by fully extending the Kaiser, Squires & Broadhurst method to include higher-order lensing image characteristics (HOLICs) introduced by Okura, Umetsu, & Futamase. We take into account explicitly the weight function in calculations of noisy shape mom...
متن کامل3D weak lensing
I propose an analysis method, based on spin-spherical harmonics and spherical Bessel functions, for large-scale weak lensing surveys which have source distance information through photometric redshifts. I show that the distance information can significantly reduce statistical errors on cosmological parameters; in particular, 3D lensing analysis offers excellent prospects for constraining the eq...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Astronomy & Astrophysics
سال: 2008
ISSN: 0004-6361,1432-0746
DOI: 10.1051/0004-6361:20078631