Reconstruction of small-scale galaxy cluster substructure with lensing flexion
Abstract
We present reconstructions of galaxy-cluster-scale mass distributions from simulated gravitational lensing data sets including strong lensing, weak lensing shear, and measurements of quadratic image distortions - flexion. The lensing data is constructed to make a direct comparison between mass reconstructions with and without flexion. We show that in the absence of flexion measurements, significant galaxy-group scale substructure can remain undetected in the reconstructed mass profiles, and that the resulting profiles underestimate the aperture mass in the substructure regions by ∼25-40 per cent. When flexion is included, subhaloes down to a mass of ∼3 × 1012 M⊙ can be detected at an angular resolution smaller than 10 arcsec. Aperture masses from profiles reconstructed with flexion match the input distribution values to within an error of ∼13 per cent, including both statistical error and scatter. This demonstrates the important constraint that flexion measurements place on substructure in galaxy clusters and its utility for producing high-fidelity mass reconstructions.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- December 2016
- DOI:
- 10.1093/mnras/stw2270
- arXiv:
- arXiv:1503.08218
- Bibcode:
- 2016MNRAS.463.4287C
- Keywords:
-
- gravitational lensing: strong;
- gravitational lensing: weak;
- methods: data analysis;
- galaxies: clusters: general;
- dark matter;
- Astrophysics - Cosmology and Nongalactic Astrophysics
- E-Print:
- 15 pages, 7 figures, 1 table. Submitted to MNRAS