Calibrating Photometric Redshift Measurements with the Multi-channel Imager(MCI) of the China Space Station Telescope(CSST)  

作　　者：Ye Cao Yan Gong Zhen-Ya Zheng Chun Xu 

机构地区：[1]Key Laboratory of Space Astronomy and Technology,National Astronomical Observatories,Chinese Academy of Sciences,Beijing 100101,China [2]School of Astronomy and Space Sciences,University of Chinese Academy of Sciences,Beijing 100049,China [3]Science Center for China Space Station Telescope,National Astronomical Observatories,Chinese Academy of Sciences,Beijing 100101,China [4]CAS Key Laboratory for Research in Galaxies and Cosmology,Shanghai Astronomical Observatory,Shanghai 200030,China [5]Division of Optical Astronomical Technologies,Shanghai Astronomical Observatory,Shanghai 200030,China [6]Joint Center of SHAO and SITP for Infrared Astronomical Instrumentation,Shanghai Astronomical Observatory,Shanghai 200030,China

出　　处：《Research in Astronomy and Astrophysics》2022年第2期204-214,共11页天文和天体物理学研究（英文版）

基　　金：the support of NSFC-11822305, NSFC-11773031, NSFC-11633004, MOST-2018YFE0120800, MOST-2020SKA0110402, and CAS Interdisciplinary Innovation Team;supported by the science research grants from the China Manned Space Project with NO.CMSCSST-2021-B01 and CMS-CSST-2021-A01. Z.Y.Z;support by the National Natural Science Foundation of China (11773051 and 12022303);the CAS Pioneer Hundred Talents Program。

摘　　要：The China Space Station Telescope(CSST) photometric survey aims to perform a high spatial resolution(~0.″ 15)photometric imaging for the targets that cover a large sky area(~17,500 deg^(2)) and wide wavelength range(from NUV to NIR). It expects to explore the properties of dark matter, dark energy, and other important cosmological and astronomical areas. In this work, we evaluate whether the filter design of the Multi-channel Imager(MCI), one of the five instruments of the CSST, can provide accurate photometric redshift(photoz) measurements with its nine medium-band filters to meet the relevant scientific objectives. We generate the mock data based on the COSMOS photometric redshift catalog with astrophysical and instrumental effects. The application of upper limit information of low signal-to-noise ratio data is adopted in the estimation of photoz. We investigate the dependency of photoz accuracy on the filter parameters, such as band position and width. We find that the current MCI filter design can achieve good photoz measurements with accuracy σ_(z)■ 0.017 and outlier fraction f_(c)■ 2.2%. It can effectively improve the photoz measurements of the main CSST survey using the Survey Camera to an accuracy σ_(z)■ 0.015 and outlier fraction f_(c)■ 1.5%. This indicates that the original MCI filters are proper for the photoz calibration.

关 键 词：cosmology:observations (cosmology:)large-scale structure of universe galaxies:distances and redshifts 

分 类 号：P159[天文地球—天文学]