Survey of Gravitationally-lensed Objects in HSC Imaging (SuGOHI). I. Automatic search for galaxy-scale strong lenses. (1st September 2017)

• Record Type: Journal Article
• Authors: Sonnenfeld, Alessandro; Chan, James H H; Shu, Yiping; More, Anupreeta; Oguri, Masamune; Suyu, Sherry H; Wong, Kenneth C; Lee, Chien-Hsiu; Coupon, Jean; Yonehara, Atsunori; Bolton, Adam S; Jaelani, Anton T; Tanaka, Masayuki; Miyazaki, Satoshi; Komiyama, Yutaka
• Is Part Of: Publications of the Astronomical Society of Japan. Volume 70:Number SP1(2018)
• Publication Date: 2017-09-01
• Subjects: galaxies: elliptical and lenticular, cD -- gravitational lensing: strong -- surveys; Astronomy -- Periodicals; 520.5
• DOI: 10.1093/pasj/psx062
• Languages: English
• ISSNs: 0004-6264

Abstract

Abstract: The Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) is an excellent survey for the search for strong lenses, thanks to its area, image quality, and depth. We use three different methods to look for lenses among 43000 luminous red galaxies from the Baryon Oscillation Spectroscopic Survey (BOSS) sample with photometry from the S16A internal data release of the HSC-SSP. The first method is a newly developed algorithm, named YattaLens, which looks for arc-like features around massive galaxies and then estimates the likelihood of an object being a lens by performing a lens model fit. The second method, Chitah, is a modeling-based algorithm originally developed to look for lensed quasars. The third method makes use of spectroscopic data to look for emission lines from objects at a different redshift from that of the main galaxy. We find 15 definite lenses, 36 highly probable lenses, and 282 possible lenses. Among the three methods, YattaLens, which was developed specifically for this study, performs best in terms of both completeness and purity. Nevertheless, five highly probable lenses were missed by YattaLens but found by the other two methods, indicating that the three methods are highly complementary. Based on these numbers, we expect to find ∼300 definite or probable lenses by the end of the HSC-SSP.