The CFHT large area U-band deep survey (CLAUDS)
The CFHT large area U-band deep survey (CLAUDS)
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CFHT大面积U波段深部勘测（CLAUDS）
DOI：
10.1093/mnras/stz2522
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发表时间：
2019
影响因子：
4.8
通讯作者：
Thibert Nathalie
中科院分区：
文献类型：
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作者：
Sawicki Marcin;Arnouts Stephane;Huang Jiasheng;Coupon Jean;Golob Anneya;Gwyn Stephen;Foucaud Sebastien;Moutard Thibaud;Iwata Ikuru;Liu Chengze;Chen Lingjian;Desprez Guillaume;Harikane Yuichi;Ono Yoshiaki;Strauss Michael A;Tanaka Masayuki;Thibert Nathalie
加拿大-法国-夏威夷望远镜大区域U波段深度调查(CLUDS)使用CFHT上的MegaCam马赛克成像器拍摄的数据来生成18.60 °$^2$的图像，半高宽的中位数为$U=27.92 弧秒，中位数深度为$U=27.1$AB(在2 弧秒孔径中为5$\ $)，选定的区域总计1.36 °$^2$，达到$U=27.7$ AB的中位数深度。这些是迄今为止在这一大片区域组装的最深的U波段图像。这些数据位于$Grizy$中的四个区域和几个窄带滤光片中，这些区域也被成像到相对微弱的水平，作为Hyper SuPrime-Cam(HSC)斯巴鲁战略计划(HSC-SSP)的一部分。在大型天气观测望远镜问世之前，这些CFHT和斯巴鲁数据集在面积和深度的组合上仍将是无与伦比的。本文概述了Clauds的科学动机，并详细介绍了观测策略、观测、数据简化以及与HSC-SSP的数据合并。这些深层数据的三个早期应用被用来说明数据集的潜力：深带星系数计数、z$\sim$3 Lyman Break星系选择，以及通过将CLAUDS U添加到Subaru HSC$GREZY$光度学来改进光度学红移。
The Canada–France–Hawaii Telescope (CFHT) Large AreaU-band Deep Survey (CLAUDS) uses data taken with the MegaCam mosaic imager on CFHT to produce images of 18.60 deg$^2$with median seeing of FWHM = 0.92 arcsec and to a median depth of $U = 27.1$ AB (5$\sigma$ in 2 arcsec apertures), with selected areas that total 1.36 deg$^2$reaching a median depth of $U=27.7$ AB. These are the deepestU-band images assembled to date over this large an area. These data are located in four fields also imaged to comparably faint levels in $grizy$ and several narrowband filters as part of the Hyper Suprime–Cam (HSC) Subaru Strategic Program (HSC-SSP). These CFHT and Subaru data sets will remain unmatched in their combination of area and depth until the advent of the Large Synoptic Survey Telescope. This paper provides an overview of the scientific motivation for CLAUDS and gives details of the observing strategy, observations, data reduction, and data merging with the HSC-SSP. Three early applications of these deep data are used to illustrate the potential of the data set: deepU-band galaxy number counts,z$\sim$ 3 Lyman break galaxy selection, and photometric redshifts improved by adding CLAUDSUto the Subaru HSC $grizy$ photometry.