摘要 宇宙时空的加速膨胀是20世纪自然科学最伟大的发现之一,探索其背后的物理机制是当前物理学和天文学的关键科学任务.在此研究领域,亟待解决的问题包括:(1)如何从海量观测数据中提取暗能量相关的核心信息?(2)暗能量是否具有动力学性质?(3)暗能量的本质是什么?暗能量研究的主要方法是联合多种探测手段,通过精准测量宇宙的膨胀率和结构形成来获取暗能量性质.大型星系红移巡天为暗能量研究提供了关键的数据支持.我们从巡天样本中提取重子声波振荡(baryon acoustic oscillations,BAO)和红移空间畸变(redshift space distortions,RSD)等重要的宇宙学探针,分别用于测量宇宙的膨胀率和结构增长率,开展暗能量研究.大型巡天项目斯隆数字巡天(Sloan Digital Sky Survey,SDSS)已成功获取了百万量级的高质量星系光谱,测绘了迄今为止最大的宇宙三维图像,并将宇宙距离测量精度提高到1%,在高精度暗能量检验中发挥至关重要的作用.本文主要介绍过去10年内国际上最大的星系红移巡天项目——SDSS三期的重子振荡光谱巡天(Baryon Oscillation Spectroscopic Survey,BOSS,2009~2014年)和四期的拓展重子振荡光谱巡天(extended Baryon Oscillation Spectroscopic Survey,eBOSS,2014~2019年),以及我们依托BOSS和e BOSS巡天开展暗能量研究方面的最新进展. The accelerating expansion of the Universe is one of the most significant discoveries in sciences in the 20 th century,and revealing the underlying physics is a key scientific mission in modern physics and astronomy.Specifically,problems to be tackled include:(1)How to extract information relevant to dark energy from observations?(2)Is dark energy dynamical?(3)What is the nature of dark energy?Dark energy leaves imprints on the expansion rate and structural growth history of the Universe,which can be probed respectively by the baryonic acoustic oscillations(BAO)and redshift space distortions(RSD).BAO and RSD are specific three-dimensional clustering patterns of galaxies in redshift space,which are best measured from large galaxy spectroscopic surveys.Large galaxy surveys including the Sloan Digital Sky Survey(SDSS),Two-Degree-Field Galaxy Redshift Survey(2 d FGRS),Wiggle Z,the Galaxy And Mass Assembly(GAMA)survey,and so on,have taken millions of high-quality spectra of distant galaxies,and have created the largest three-dimensional map of the Universe to date.This has raised the precision of the distance measurement to a level of one per cent,which is crucial to observational tests of dark energy.In this article,we introduce the world largest galaxy redshift surveys in the last decade,including the Baryon Oscillation Spectroscopic Survey(BOSS)as part of the SDSS-III program,and the extended Baryon Oscillation Spectroscopic Survey(e BOSS)of SDSS-IV,and review the progress of cosmological implications,especially on studies of dark energy.During 2009-2014,the BOSS survey took approximately one million spectra of red galaxies below redshift 0.6.To fully use the tomographic information of the galaxy clustering along the past lightcone,which is crucial for probing the time evolution of dark energy,we measured the BAO and RSD in multiple over-lapping redshift slices.This made it possible to reconstruct the evolution history of dark energy at a high resolution in redshift.Interestingly,we found that a dynamical dark ener
出处 《科学通报》 EI CAS CSCD 北大核心 2021年第11期1336-1345,共10页 Chinese Science Bulletin
基金 国家重点基础研究发展计划(2018YFA0404503) 国家杰出青年科学基金(11925303) 国家自然科学基金(11720101004,11673025,11890691)资助。
关键词 星系巡天 重子声波振荡 红移空间畸变 宇宙膨胀率 宇宙结构增长率 暗能量 galaxy survey baryonic acoustic oscillations redshift space distortions cosmic expansion rate growth rate of cosmic structure dark energy
