銀河団重力レンズ効果とCMB重力レンズ効果との相関によるニュートリノ質量への制限

2021 Fiscal Year Annual Research Report

• Project/Area Number: 19J22222
• Research Institution: The University of Tokyo
• Principal Investigator: LI Xiangchong 東京大学, 理学系研究科, 特別研究員(DC1)
• Project Period (FY): 2019-04-25 – 2022-03-31
• Keywords: gravitational lensing / cosmology observations / image processing / galaxy clusters

Outline of Annual Research Achievements

I analytically developed an improved version of the Fourier Power Function Shapelets (FPFS) algorithm for accurate and fast shear estimation. The method now includes analytic corrections for sources of bias that plague all shape measurement algorithms: including noise bias (due to noise in nonlinear combinations of observable quantities) and selection bias (due to sheared galaxies being more or less likely to be detected). Crucially, these analytic solutions do not rely on calibration from external image simulations. For isolated galaxies, the small residual less than 0.001 multiplicative bias and less than 0.0001 additive bias now meet science requirements for Stage IV experiments. FPFS also works accurately for faint galaxies and robustly against stellar contamination.

I conducted several systematic null tests for the HSC three-year cosmic shear measurement. One is to test the systematics in cosmic shear measurement caused by model residuals of point spread function due to diffraction of telescope and atmosphere. I cross-correlate galaxy shape with star shape to detect the PSF modelling residual in the galaxy shapes. The other null test is to check the B-mode systematics in the weak-lensing science. Then I looked into the influence of baryonic effect, the influence of the intrinsic alignment in the cosmic shear measurement. I have built up the analysis pipeline for HSC three year weak lensing cosmological constraints.

Research Progress Status

令和3年度が最終年度であるため、記入しない。

Strategy for Future Research Activity

令和3年度が最終年度であるため、記入しない。

Research Products

• [Journal Article] The three-year shear catalog of the Subaru Hyper Suprime-Cam SSP Survey (2022)
  • Author(s): Li Xiangchong、Miyatake Hironao、Luo Wentao、More Surhud、Oguri Masamune、Hamana Takashi、Mandelbaum Rachel、Shirasaki Masato、Takada Masahiro、Armstrong Robert、Kannawadi Arun、Takita Satoshi、Miyazaki Satoshi、Nishizawa Atsushi J、Plazas Malagon Andres A、Strauss Michael A、Tanaka Masayuki、Yoshida Naoki
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 74 Pages: 421～459
  • DOI: 10.1093/pasj/psac006
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Weak gravitational lensing shear measurement with FPFS: analytical mitigation of noise bias and selection bias (2022)
  • Author(s): Li Xiangchong、Li Yin、Massey Richard
  • Journal Title: Monthly Notices of the Royal Astronomical Society Volume: 511 Pages: 4850～4860
  • DOI: 10.1093/mnras/stac342
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Three-dimensional Reconstruction of Weak-lensing Mass Maps with a Sparsity Prior. I. Cluster Detection (2021)
  • Author(s): Li Xiangchong、Yoshida Naoki、Oguri Masamune、Ikeda Shiro、Luo Wentao
  • Journal Title: The Astrophysical Journal Volume: 916 Pages: 67～67
  • DOI: 10.3847/1538-4357/ac0625
  • Peer Reviewed / Open Access
• [Journal Article] The Stellar Mass in and around Isolated Central Galaxies: Connections to the Total Mass Distribution through Galaxy-Galaxy Lensing in the Hyper Suprime-Cam Survey (2021)
  • Author(s): Wang Wenting、Li Xiangchong、Shi Jingjing、Han Jiaxin、Yasuda Naoki、Jing Yipeng、More Surhud、Takada Masahiro、Miyatake Hironao、Nishizawa Atsushi J.
  • Journal Title: The Astrophysical Journal Volume: 919 Pages: 25～25
  • DOI: 10.3847/1538-4357/ac0e38
  • Peer Reviewed / Int'l Joint Research