Strong Lensing Reconstruction
Abstract
We present a general linear algorithm for measuring the surface mass density 1-κ from the observable reduced shear g=γ/(1-κ) in the strong lensing regime. We show that in general, the observed polarization field can be decomposed into ``electric'' and ``magnetic'' components, which have independent and redundant solutions, but orthogonal noise properties. By combining these solutions, one can increase the signal-to-noise ratio by sqrt(2). The solutions allow dynamic optimization of signal and noise, both in real and Fourier space (using arbitrary smoothing windows). Boundary conditions have no effect on the reconstructions, apart from its effect on the signal-to-noise ratio. Many existing reconstruction techniques are recovered as special cases of this framework. The magnetic solution has the added benefit of yielding the global and local parity of the reconstruction in a single step.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- May 2000
- DOI:
- 10.1086/312652
- arXiv:
- arXiv:astro-ph/9910502
- Bibcode:
- 2000ApJ...534L..19P
- Keywords:
-
- COSMOLOGY: GRAVITATIONAL LENSING;
- Astrophysics
- E-Print:
- final accepted version for ApJL