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| SAGES南山1米大视场望远镜g、r、i波段测光数据流量定标 | |
| Alternative Title | Photometric calibration of the Stellar Abundance and Galactic Evolution Survey (SAGES): Nanshan One-meter Wide-field Telescope g, r, and i band imaging data |
肖凯1,2; 苑海波1,2; 黄博闻1,2; 徐帅1,2; 郑捷3; 李春3; 范舟2; 王炜3; 赵刚3; 冯国杰4 ; 张轩4; 刘进忠4; 张若羿1,2; 杨琳5; 张余4; 白春海4; 牛虎彪4; 艾力·伊沙木丁4; 马路4
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| 2023 | |
| Source Publication | 科学通报
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| ISSN | 0023-074X |
| Volume | 68Issue:21Pages:2790-2804 |
| Contribution Rank | 4 |
| Abstract | 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. |
| Other Abstract | 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 PS1 magnitudes 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% relative to the other channel, with a maximum value of 4%. In addition, significant spatial variations of the stellar flat fitting residual are found in all the g, r, and i filters. For each band, the significant spatial structure is similar on a daily basis but different over longer timescales(e.g., seasonally). To correct the spatial-dependence errors presented by the flat-field correction fitting residuals, we used the fitting residuals from a single day to correct all the observed images taken on that day. Using repeated sources in the adjacent images, we checked and discovered internal consistency of about 1-2 millimagnitude in all the filters. Using the PS1 magnitudes synthesized by Gaia DR3 BP/RP spectra by the synthetic photometry method, we found that the photometric calibration uniformity is about 2.4, 2.3, and 0.9 millimagnitude for the g, r, and i bands, respectively, at a spatial resolution of 1.3°. A detailed comparison between the spectroscopy-based SCR and photometric-based SCR method magnitude offsets was performed, and we achieved an internal consistency precision of about 2 millimagnitude or better with resolutions of 1.3° for all the filters. And the difference between the spectroscopy-based SCR method and the photometric-based SCR method is mainly from the position-dependent systematic error of the dust reddening map of Schlegel et al. used in SCR' method. This work has successfully broken through the "1% accuracy bottleneck" of groundbased wide-field photometric survey photometric calibration. Our results can provide method and experience references for the photometric calibration of upcoming survey data. |
| Keyword | 大视场测光巡天 流量定标 恒星参数 星际消光 |
| DOI | 10.48550/arXiv.2307.13238 |
| URL | 查看原文 |
| Indexed By | EI ; 中文核心期刊要目总览 ; CSCD |
| Language | 中文 |
| CSCD ID | CSCD:7515096 |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://ir.xao.ac.cn/handle/45760611-7/6634 |
| Collection | 光学天文与技术应用研究室 科研仪器设备产出_利用南山1米大视场望远镜（NOWT）观测数据的文章 |
| Corresponding Author | 苑海波 |
| Affiliation | 1.北京师范大学天文与天体物理前沿科学研究所; 2.北京师范大学天文系; 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; 4.中国科学院新疆天文台; 5.北京师范大学人工智能学院 |
| Recommended Citation GB/T 7714 | 肖凯,苑海波,黄博闻,等. SAGES南山1米大视场望远镜g、r、i波段测光数据流量定标[J]. 科学通报,2023,68(21):2790-2804. |
| APA | 肖凯.,苑海波.,黄博闻.,徐帅.,郑捷.,...&马路.(2023).SAGES南山1米大视场望远镜g、r、i波段测光数据流量定标.科学通报,68(21),2790-2804. |
| MLA | 肖凯,et al."SAGES南山1米大视场望远镜g、r、i波段测光数据流量定标".科学通报 68.21(2023):2790-2804. |
| Files in This Item: | ||||||
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| 肖凯-2023-SAGES南山1米大视场（5390KB） | 期刊论文 | 出版稿 | 开放获取 | CC BY-NC-SA | View Application Full Text | |
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