The VLT Survey Telescope ATLAS
The VLT Survey Telescope ATLAS
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DOI：
10.1093/mnras/stv1130
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发表时间：
2015-02
影响因子：
4.8
通讯作者：
T. Shanks;N. Metcalfe;B. Chehade;J. Findlay;M. Irwin;E. González-Solares;J. Lewis;A. Yoldas
中科院分区：
文献类型：
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作者：
T. Shanks;N. Metcalfe;B. Chehade;J. Findlay;M. Irwin;E. González-Solares;J. Lewis;A. Yoldas
VLT巡天望远镜ATLAS巡天是一项光学乌戈尔巡天，其目标是覆盖南天104700 deg^2，达到与斯隆数字巡天（SDSS）相似的深度。从剑桥天文巡天单位提供的简化图像和天体目录中，我们首先发现，中位视宁度范围从0.8弧秒半高宽（半高宽）（i）到1.0弧秒（u），明显优于SDSS的1.2-1.5弧秒视宁度。恒星源的5σ磁极限为r_AB = 22.7，在所有波段，这些极限至少和SDSS一样微弱。SDSS和ATLAS在星系光度学上更等效，除了在Z波段，ATLAS具有显着更高的吞吐量。我们通过将m < 16的星星星等与AAVSO测光全天巡天的gri星等进行比较，并外推到u和z，改进了原来的ESO星等零点，使零点精确到± 0.02等。最后，我们将250 ° ^2区域内的星星和星系数与SDSS和其他计数数据进行了比较，发现吻合得很好。ATLAS数据产品可以从ESO科学档案中检索，而对调查科学分析的支持则由爱丁堡广域天文单位运营的OmegaCAM科学档案提供。
The VLT Survey Telescope ATLAS survey is an optical ugriz survey aiming to cover ≈4700 deg^2 of the southern sky to similar depths as the Sloan Digital Sky Survey (SDSS). From reduced images and object catalogues provided by the Cambridge Astronomical Surveys Unit, we first find that the median seeing ranges from 0.8 arcsec FWHM (full width at half-maximum) in i to 1.0 arcsec in u, significantly better than the 1.2–1.5 arcsec seeing for SDSS. The 5σ mag limit for stellar sources is r_AB = 22.7 and in all bands these limits are at least as faint as SDSS. SDSS and ATLAS are more equivalent for galaxy photometry except in the z band where ATLAS has significantly higher throughput. We have improved the original ESO magnitude zero-points by comparing m < 16 star magnitudes with the AAVSO Photometric All-Sky Survey in gri, also extrapolating into u and z, resulting in zero-points accurate to ≈ ± 0.02 mag. We finally compare star and galaxy number counts in a 250 deg^2 area with SDSS and other count data and find good agreement. ATLAS data products can be retrieved from the ESO Science Archive, while support for survey science analyses is provided by the OmegaCAM Science Archive, operated by the Wide-Field Astronomy Unit in Edinburgh.