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arXiv 0812.0649astro-ph
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斯隆数字巡天第七次数据发布

The Seventh Data Release of the Sloan Digital Sky Survey

K. Abazajian

摘要:

本文介绍了斯隆数字巡天(SDSS)的第七次数据发布,标志着SDSS最初目标的完成和SDSS-II阶段的结束。它包含了11663 deg^2的成像数据,其中大部分比之前发布的数据增加了大约2000 deg^2,位于银河系低纬度地区。该目录包含3.57亿个不同天体的五波段测光。巡天测量还包括沿南银帽天球赤道在250度^[2]范围内重复测光。这些数据的共同增加比主要调查大约暗两个数量级。现在,在北银河帽7500 deg^2的连续区域内完成了光谱测量,填补了之前数据发布中存在的空白。总共有超过160万个光谱,包括930,000个星系,120,000个类星体和460,000颗恒星。发布的数据包括改进了银河系低纬度的恒星测光。天体测量都已经用第二版的USNO CCD天体仪目录(UCAC-2)重新校准,将亮端的均方根统计误差减少到每个坐标45毫角秒。亮星系光度计的系统误差比以前报道的大多数星系的误差要小。最后,我们描述了一系列的改进,光谱的减少,包括更好的平场和改进的波长校准在蓝端,更好地处理具有极强的窄发射线的对象,和改进的恒星金属丰度的测定。(节录)

英文摘要:

This paper describes the Seventh Data Release of the Sloan Digital Sky Survey (SDSS), marking the completion of the original goals of the SDSS and the end of the phase known as SDSS-II. It includes 11663 deg^2 of imaging data, with most of the roughly 2000 deg^2 increment over the previous data release lying in regions of low Galactic latitude. The catalog contains five-band photometry for 357 million distinct objects. The survey also includes repeat photometry over 250 deg^2 along the Celestial Equator in the Southern Galactic Cap. A coaddition of these data goes roughly two magnitudes fainter than the main survey. The spectroscopy is now complete over a contiguous area of 7500 deg^2 in the Northern Galactic Cap, closing the gap that was present in previous data releases. There are over 1.6 million spectra in total, including 930,000 galaxies, 120,000 quasars, and 460,000 stars. The data release includes improved stellar photometry at low Galactic latitude. The astrometry has all been recalibrated with the second version of the USNO CCD Astrograph Catalog (UCAC-2), reducing the rms statistical errors at the bright end to 45 milli-arcseconds per coordinate. A systematic error in bright galaxy photometr is less severe than previously reported for the majority of galaxies. Finally, we describe a series of improvements to the spectroscopic reductions, including better flat-fielding and improved wavelength calibration at the blue end, better processing of objects with extremely strong narrow emission lines, and an improved determination of stellar metallicities. (Abridged)

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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