deepCR宇宙线识别方法是哈勃空间望远镜(Hubble Space Telescope,HST)剔除宇宙线的有效方法,但这一方法是否可以满足中国空间站望远镜(China Space Station Telescope,CSST)的要求,始终缺乏科学的定量分析。采用哈勃望远镜的真实观测数...deepCR宇宙线识别方法是哈勃空间望远镜(Hubble Space Telescope,HST)剔除宇宙线的有效方法,但这一方法是否可以满足中国空间站望远镜(China Space Station Telescope,CSST)的要求,始终缺乏科学的定量分析。采用哈勃望远镜的真实观测数据,对deepCR宇宙线识别方法进行了深入分析,对其稳定性和可用性进行了实测研究。结果表明,deepCR在天空背景区域识别宇宙线的灵敏度较高,但越靠近星像中心,deepCR识别宇宙线的灵敏度越低。分析了宇宙线密度和测光精度的关系,发现当宇宙线密度达到9%时,几乎100%的星受到宇宙线的污染;当宇宙线密度达到14%时,对于不同轮廓面积的星,存在20%~50%的异常测光结果。实验结果表明,deepCR宇宙线识别模型稳定性相对较好,一次建模后可以在较长时间内应用。但在高精度测光等应用场景仍面临着一系列问题,需要有针对性的解决方案。展开更多
"科学与技术跨学科整合研究学者"项目(Cross-Disciplinary Scholars in Science and Technology,CSST)由美国加州大学洛杉矶分校(UCLA)于2008年设立,旨在增进不同学科间的沟通交流,培养学生的跨学科整合研究能力,提升UCLA国..."科学与技术跨学科整合研究学者"项目(Cross-Disciplinary Scholars in Science and Technology,CSST)由美国加州大学洛杉矶分校(UCLA)于2008年设立,旨在增进不同学科间的沟通交流,培养学生的跨学科整合研究能力,提升UCLA国际博士研究生招生成果。设立至今,CSST项目已建立了完善的暑期研究计划及杰出人才的培训选拔机制。2015年,UCLA化学系教授林永雅(Yung-Ya Lin)代表UCLA到中国进行CSST项目的招生面试。借此机会,本刊对林永雅教授进行了专访,以深入了解CSST项目的宗旨、人才选拔和培养机制、与中国高校开展的合作等。在采访过程中,林教授指出,CSST项目建立了完善的人才选拔和培养机制,并积极开展与中国国家留学基金管理委员会(CSC)的合作,未来将进一步扩展与中国高校的合作领域。此次采访得到了中国国家留学基金管理委员会的大力支持。展开更多
我国预计2025年发射的巡天空间望远镜(Chinese Space Station Telescope,CSST),主要用于开展大规模的多色成像与无缝光谱巡天工作。发射前需要利用地基望远镜对空间望远镜的光学成像系统、探测器,以及设备长时间运行稳定性进行地面测试...我国预计2025年发射的巡天空间望远镜(Chinese Space Station Telescope,CSST),主要用于开展大规模的多色成像与无缝光谱巡天工作。发射前需要利用地基望远镜对空间望远镜的光学成像系统、探测器,以及设备长时间运行稳定性进行地面测试。设计了兴隆观测基地80 cm望远镜的无缝光谱地面测试,利用A型恒星、B型恒星和沃尔夫拉叶星HD4004的强吸收和发射线特征,拟合色散方程,并发现色散方程具有空间分布特征。对HR3173的53条数据的零级谱位置信息及色散方程系数进行了二次曲面拟合,并利用该曲面对HR3173零级像位置范围内的HR718数据进行了波长定标,得到的CCD上8×13 pixels范围内的平均视向速度精度为51 km/s。展开更多
Gravitational waves(GWs) from compact binary coalescences encode the absolute luminosity distances of GW sources. Once the redshifts of GW sources are known, one can use the distance-redshift relation to constrain cos...Gravitational waves(GWs) from compact binary coalescences encode the absolute luminosity distances of GW sources. Once the redshifts of GW sources are known, one can use the distance-redshift relation to constrain cosmological parameters. One way to obtain the redshifts is to localize GW sources by GW observations and then use galaxy catalogs to determine redshifts from a statistical analysis of redshift information of the potential host galaxies, commonly referred to as the dark siren method. The third-generation(3G) GW detectors are planned to work in the 2030s and will observe numerous compact binary coalescences.Using these GW events as dark sirens requires high-quality galaxy catalogs from future sky survey projects. The China Space Station Telescope(CSST) will be launched in 2024 and will observe billions of galaxies within a 17500 deg^(2) survey area with redshift up to z ~ 4, providing photometric and spectroscopic galaxy catalogs. In this work, we simulate the CSST galaxy catalogs and the 5-year GW data from the 3G GW detectors and combine them to infer the Hubble constant(H_(0)). Our results show that the measurement precision of H0could reach the sub-percent level, meeting the standard of precision cosmology. We conclude that the synergy between CSST and the 3G GW detectors is of great significance in measuring the Hubble constant.展开更多
中国空间站工程巡天望远镜(China Space Station Telescope,CSST)计划于2024年发射,将主要开展高空间分辨率、天区大面积(约17500平方度)的多色成像与无缝光谱巡天,预计可极大地提高白矮星的观测样本数量.本文分别基于盖亚第三次早期数...中国空间站工程巡天望远镜(China Space Station Telescope,CSST)计划于2024年发射,将主要开展高空间分辨率、天区大面积(约17500平方度)的多色成像与无缝光谱巡天,预计可极大地提高白矮星的观测样本数量.本文分别基于盖亚第三次早期数据发布(Gaia EDR3)和斯隆数字巡天第十六次数据发布(SDSS DR16)探测到的白矮星候选体和已确认的白矮星样本,进行统计分析,得出恒星参数的分布(多波段星等、有效温度、表面重力加速度、距离和质量),并分析各参数之间的相关性,计算白矮星的空间密度;最后,结合CSST的观测性能,预计其将探测到的白矮星数目,为基于CSST主巡天数据开展大样本暗弱白矮星搜寻和研究工作提供预估和分析.展开更多
The Chinese Space Station Telescope(CSST)is a cutting-edge two-meter astronomical space telescope currently under construction.Its primary Survey Camera(SC)is designed to conduct large-area imaging sky surveys using a...The Chinese Space Station Telescope(CSST)is a cutting-edge two-meter astronomical space telescope currently under construction.Its primary Survey Camera(SC)is designed to conduct large-area imaging sky surveys using a sophisticated seven-band photometric system.The resulting data will provide unprecedented data for studying the structure and stellar populations of the Milky Way.To support the CSST development and scientific projects related to its survey data,we generate the first comprehensive Milky Way stellar mock catalogue for the CSST SC photometric system using the TRILEGAL stellar population synthesis tool.The catalogue includes approximately 12.6 billion stars,covering a wide range of stellar parameters,photometry,astrometry,and kinematics,with magnitude reaching down to g=27.5 mag in the AB magnitude system.The catalogue represents our benchmark understanding of the stellar populations in the Milky Way,enabling a direct comparison with the future CSST survey data.Particularly,it sheds light on faint stars hidden from current sky surveys.Our crowding limit analysis based on this catalogue provides compelling evidence for the extension of the CSST Optical Survey(OS)to cover low Galactic latitude regions.The strategic extension of the CSST-OS coverage,combined with this comprehensive mock catalogue,will enable transformative science with the CSST.展开更多
文摘deepCR宇宙线识别方法是哈勃空间望远镜(Hubble Space Telescope,HST)剔除宇宙线的有效方法,但这一方法是否可以满足中国空间站望远镜(China Space Station Telescope,CSST)的要求,始终缺乏科学的定量分析。采用哈勃望远镜的真实观测数据,对deepCR宇宙线识别方法进行了深入分析,对其稳定性和可用性进行了实测研究。结果表明,deepCR在天空背景区域识别宇宙线的灵敏度较高,但越靠近星像中心,deepCR识别宇宙线的灵敏度越低。分析了宇宙线密度和测光精度的关系,发现当宇宙线密度达到9%时,几乎100%的星受到宇宙线的污染;当宇宙线密度达到14%时,对于不同轮廓面积的星,存在20%~50%的异常测光结果。实验结果表明,deepCR宇宙线识别模型稳定性相对较好,一次建模后可以在较长时间内应用。但在高精度测光等应用场景仍面临着一系列问题,需要有针对性的解决方案。
文摘"科学与技术跨学科整合研究学者"项目(Cross-Disciplinary Scholars in Science and Technology,CSST)由美国加州大学洛杉矶分校(UCLA)于2008年设立,旨在增进不同学科间的沟通交流,培养学生的跨学科整合研究能力,提升UCLA国际博士研究生招生成果。设立至今,CSST项目已建立了完善的暑期研究计划及杰出人才的培训选拔机制。2015年,UCLA化学系教授林永雅(Yung-Ya Lin)代表UCLA到中国进行CSST项目的招生面试。借此机会,本刊对林永雅教授进行了专访,以深入了解CSST项目的宗旨、人才选拔和培养机制、与中国高校开展的合作等。在采访过程中,林教授指出,CSST项目建立了完善的人才选拔和培养机制,并积极开展与中国国家留学基金管理委员会(CSC)的合作,未来将进一步扩展与中国高校的合作领域。此次采访得到了中国国家留学基金管理委员会的大力支持。
文摘我国预计2025年发射的巡天空间望远镜(Chinese Space Station Telescope,CSST),主要用于开展大规模的多色成像与无缝光谱巡天工作。发射前需要利用地基望远镜对空间望远镜的光学成像系统、探测器,以及设备长时间运行稳定性进行地面测试。设计了兴隆观测基地80 cm望远镜的无缝光谱地面测试,利用A型恒星、B型恒星和沃尔夫拉叶星HD4004的强吸收和发射线特征,拟合色散方程,并发现色散方程具有空间分布特征。对HR3173的53条数据的零级谱位置信息及色散方程系数进行了二次曲面拟合,并利用该曲面对HR3173零级像位置范围内的HR718数据进行了波长定标,得到的CCD上8×13 pixels范围内的平均视向速度精度为51 km/s。
基金supported by the National SKA Program of China (Grant Nos.2022SKA0110200, and 2022SKA0110203)the National Natural Science Foundation of China (Grant Nos. 11975072, 11875102, and 11835009)+1 种基金the science research grants from the China Manned Space Project (Grant No. CMS-CSST-2021-B01)the 111 Project (Grant No. B16009)。
文摘Gravitational waves(GWs) from compact binary coalescences encode the absolute luminosity distances of GW sources. Once the redshifts of GW sources are known, one can use the distance-redshift relation to constrain cosmological parameters. One way to obtain the redshifts is to localize GW sources by GW observations and then use galaxy catalogs to determine redshifts from a statistical analysis of redshift information of the potential host galaxies, commonly referred to as the dark siren method. The third-generation(3G) GW detectors are planned to work in the 2030s and will observe numerous compact binary coalescences.Using these GW events as dark sirens requires high-quality galaxy catalogs from future sky survey projects. The China Space Station Telescope(CSST) will be launched in 2024 and will observe billions of galaxies within a 17500 deg^(2) survey area with redshift up to z ~ 4, providing photometric and spectroscopic galaxy catalogs. In this work, we simulate the CSST galaxy catalogs and the 5-year GW data from the 3G GW detectors and combine them to infer the Hubble constant(H_(0)). Our results show that the measurement precision of H0could reach the sub-percent level, meeting the standard of precision cosmology. We conclude that the synergy between CSST and the 3G GW detectors is of great significance in measuring the Hubble constant.
文摘中国空间站工程巡天望远镜(China Space Station Telescope,CSST)计划于2024年发射,将主要开展高空间分辨率、天区大面积(约17500平方度)的多色成像与无缝光谱巡天,预计可极大地提高白矮星的观测样本数量.本文分别基于盖亚第三次早期数据发布(Gaia EDR3)和斯隆数字巡天第十六次数据发布(SDSS DR16)探测到的白矮星候选体和已确认的白矮星样本,进行统计分析,得出恒星参数的分布(多波段星等、有效温度、表面重力加速度、距离和质量),并分析各参数之间的相关性,计算白矮星的空间密度;最后,结合CSST的观测性能,预计其将探测到的白矮星数目,为基于CSST主巡天数据开展大样本暗弱白矮星搜寻和研究工作提供预估和分析.
基金supported by the National Key R&D Program of China(Grant Nos.2021YFC2203100,and 2021YFC2203104)the science research grants from the China Manned Space Project(Grant No.CMSCSST-2021-A08)+4 种基金the National Natural Science Foundation of China(Grant No.12003001)the Anhui Project(Grant No.Z010118169)the support of the National Natural Science Foundation of China(Grant No.12203100)the National Natural Science Foundation of China(Grant No.12273077)the support from Padova University through the research project PRD 2021。
文摘The Chinese Space Station Telescope(CSST)is a cutting-edge two-meter astronomical space telescope currently under construction.Its primary Survey Camera(SC)is designed to conduct large-area imaging sky surveys using a sophisticated seven-band photometric system.The resulting data will provide unprecedented data for studying the structure and stellar populations of the Milky Way.To support the CSST development and scientific projects related to its survey data,we generate the first comprehensive Milky Way stellar mock catalogue for the CSST SC photometric system using the TRILEGAL stellar population synthesis tool.The catalogue includes approximately 12.6 billion stars,covering a wide range of stellar parameters,photometry,astrometry,and kinematics,with magnitude reaching down to g=27.5 mag in the AB magnitude system.The catalogue represents our benchmark understanding of the stellar populations in the Milky Way,enabling a direct comparison with the future CSST survey data.Particularly,it sheds light on faint stars hidden from current sky surveys.Our crowding limit analysis based on this catalogue provides compelling evidence for the extension of the CSST Optical Survey(OS)to cover low Galactic latitude regions.The strategic extension of the CSST-OS coverage,combined with this comprehensive mock catalogue,will enable transformative science with the CSST.
