Elliptical-weighted HOLICs for weak lensing shear measurement. II. Point-spread function correction and application to A370

Yuki Okura, Toshifumi Futamase

Research output: Contribution to journalArticlepeer-review

14 Citations (Scopus)

Abstract

We developed a new method (E-HOLICs) of estimating gravitational shear by adopting an elliptical weight function to measure background galaxy images in our previous paper. Following the previous paper, in which an isotropic point-spread function (PSF) correction is calculated, in this paper we consider an anisotropic PSF correction in order to apply E-HOLICs to real data. As an example, E-HOLICs is applied to Subaru data of the massive and compact galaxy cluster A370 and is able to detect double peaks in the central region of the cluster consistent with the analysis of strong lensing. We also study the systematic error in E-HOLICs using STEP2 simulation. In particular, we consider the dependences of the signal-to-noise ratio (S/N) of background galaxies in the shear estimation. Although E-HOLICs does improve the systematic error due to the ellipticity dependence as shown in Paper I, a systematic error due to the S/N dependence remains, namely, E-HOLICs underestimates shear when background galaxies with low S/N objects are used. We discuss a possible improvement of the S/N dependence.

Original languageEnglish
Article number112
JournalAstrophysical Journal
Volume748
Issue number2
DOIs
Publication statusPublished - 2012 Apr 1

Keywords

  • galaxies: clusters: individual (A370)
  • gravitational lensing: weak

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Fingerprint Dive into the research topics of 'Elliptical-weighted HOLICs for weak lensing shear measurement. II. Point-spread function correction and application to A370'. Together they form a unique fingerprint.

Cite this