SAGES南山1米大视场望远镜g、r、i波段测光数据流量定标  

Photometric calibration of the Stellar Abundance and Galactic Evolution Survey(SAGES):Nanshan One-meter Wide-field Telescope g,r,and i band imaging data

作　　者：肖凯 苑海波 黄博闻 徐帅[1,2] 郑捷 李春 范舟 王炜[3] 赵刚 冯国杰[4] 张轩 刘进忠[4] 张若羿[1,2] 杨琳 张余[4] 白春海 牛虎彪 艾力·伊沙木丁 马路[4] Kai Xiao;Haibo Yuan;Bowen Huang;Shuai Xu;Jie Zheng;Chun Li;Zhou Fan;Wei Wang;Gang Zhao;Guojie Feng;Xuan Zhang;Jinzhong Liu;Ruoyi Zhang;Lin Yang;Yu Zhang;Chunhai Bai;Hubiao Niu;Esamdin Ali;Lu Ma(Institute for Frontiers in Astronomy and Astrophysics,Beijing Normal University,Beijing 102206,China;Department of Astronomy,Beijing Normal University,Beijing 100875,China;CAS Key Laboratory of Optical Astronomy,National Astronomical Observatories,Chinese Academy of Sciences,Beijing 100101,China;Xinjiang Astronomical Observatory,Chinese Academy of Sciences,Urumqi 830011,China;College of Artificial Intelligence,Beijing Normal University,Beijing 100875,China)

机构地区：[1]北京师范大学天文与天体物理前沿科学研究所,北京102206 [2]北京师范大学天文系,北京100875 [3]中国科学院国家天文台,中国科学院光学天文重点实验室,北京100101 [4]中国科学院新疆天文台,乌鲁木齐830011 [5]北京师范大学人工智能学院,北京100875

出　　处：《科学通报》2023年第21期2790-2804,共15页Chinese Science Bulletin

基　　金：国家自然科学基金(12173007,12222301);国家重点研发计划(2019YFA0405503);中国载人航天工程巡天空间望远镜专项(CMS-CSST-2021-A08,CMS-CSST-2021-A09)资助。

摘　　要：均匀且精确的流量定标是大视场测光巡天数据处理的难点和核心所在.本文借助LAMOST(Large Sky Area Multi-Object Fiber Spectroscopic Telescope)DR7光谱数据、修正后的Gaia EDR3测光数据和Gaia测光丰度数据,使用基于光谱的SCR(Stellar Color Regression)方法和基于测光的SCR方法(SCR′方法)构建了南山1米大视场望远镜g、r、i波段精度约为10~20毫星等的260多万颗标准星,进而对SAGES(Stellar Abundance and Galactic Evolution Survey)南山1米望远镜拍摄的约4254平方度天区的测光数据进行了相对流量定标.在此过程中,我们仔细考虑了定标零点随不同图像(时间)、探测器不同通道及星像在探测器不同位置的变化.基于修正后的Pan-STARRS(PS1)DR1测光数据,进行了绝对流量定标,并给出了南山g、r、i波段定标后的星等与PS1星等之间的相互转换关系.基于相邻图之间的共同源对定标精度进行了内部一致性检验,发现3个波段的定标精度均约为2.0毫星等.同时,我们还对定标精度做了外部检验,使用Gaia DR3无缝光谱合成的PS1星等,发现定标均匀性在1.3°分辨本领下分别为2.4、2.3和0.9毫星等.此外,本文还讨论了恒星平场和探测器通道间相对增益随时间的变化.In recent years,there have been numerous wide-field imaging surveys conducted both domestically and internationally,which have had a revolutionary impact on astronomy.Uniform and accurate photometric calibration is very challenging and plays a key role in wide-field imaging surveys.The Nanshan One-meter Wide-field Telescope,with a 1.3° field of view,was used by the Stellar Abundance and Galactic Evolution Survey(SAGES) to image 4254 square degrees of the northern sky in three broadband filters(g,r,and i).In this paper,a total of approximately 2.6 million dwarf stars were constructed as standard stars,with an accuracy of about 0.01–0.02 magnitude for each band,by combining spectroscopic data from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope(LAMOST) Data Release 7,photometric data from the corrected Gaia Early Data Release 3,and photometric metallicities obtained by Xu et al.Using the spectroscopybased stellar color regression method(SCR method) and the photometric-based SCR method(SCR′ method),we performed the relative calibration of the Nanshan One-meter Wide-field Telescope imaging data of the SAGES survey.Based on the corrected Pan-STARRS DR1(PS1) photometry,the absolute calibration was also performed,and the transform relationship between Nanshan One-meter Wide-field Telescope calibrated magnitudes and the corrected PS1magnitudes was given.In the photometric calibration process,we analyzed the dependence of the calibration zero points on different images(observation time),different gates of the CCD detector,and different CCD positions.We found that the stellar flat and the relative gain between different gates depend on time.Variations in the telescope's performance can be classified as either related to sudden changes in pointing or unrelated.By analyzing the spatial distribution of the stellar flat-field,we can verify the orientation and rotation of the horizon for the Nanshan One-meter Wide-field Telescope.The amplitude of gain variation in three channels is approximately 0.5%–0.7% r

关 键 词：大视场测光巡天 流量定标 恒星参数 星际消光 

分 类 号：P111[天文地球—天文学]