Empirical color transformations between SDSS photometry and Other photometric systems.
Empirical color transformations between SDSS photometry and Other photometric systems.
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DOI：
10.1051/0004-6361:20066082
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发表时间：
2005-08
影响因子：
0.9
通讯作者：
K. Jordi;E. Grebel;K. Ammon
中科院分区：
文献类型：
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作者：
K. Jordi;E. Grebel;K. Ammon
目标。我们分别介绍了斯隆数字巡天 (SDSS) ugriz 光度测量与 Johnson-Cousins UBVRI 系统和 Becker 的 RGU 系统之间的经验色彩转换。由于 SDSS 光度测量系统中可用的数据量很大，能够在该新系统和传统光度测量系统之间进行转换就显得尤为重要。与之前发布的转换不同，我们的计算基于 SDSS 2.5 米望远镜实际测量的恒星。 SDSS 的光度数据库在某种意义上提供了一套覆盖超过四分之一天空的单时代“三级标准”。我们的转换应该有助于它们的使用，以轻松可靠地导出相应的近似 Johnson-Cousins 或 RGU 幅度。方法。 SDSS 调查涵盖了先前在 Johnson-Cousins 系统中建立为标准字段的许多领域，特别是由 Landolt 和 Stetson 建立的字段。我们使用这些重叠场来创建光度良好的恒星样本，我们的计算转换就是基于这些样本。对于 RGU 光度测量，我们使用了在新的巴塞尔高纬度实地星巡天框架中观测到的视野。结果。我们计算了 SDSS 光度测定法与 Johnson-Cousins UBVRI 和 Becker RGU 系统之间的经验颜色变换。对于所有变换，我们发现线性关系就足够了。此外，我们表明 Johnson-Cousins 和 SDSS 系统之间的转换对金属丰度有轻微的依赖性。
Aims. We present empirical color transformations between the Sloan Digital Sky Survey (SDSS) ugriz photometry and the Johnson-Cousins UBVRI system and Becker's RGU system, respectively. Owing to the magnitude of data that is becoming available in the SDSS photometric system it is particularly important to be able to convert between this new system and traditional photometric systems. Unlike earlier published transformations we based our calculations on stars actually measured by the SDSS with the SDSS 2.5-m telescope. The photometric database of the SDSS provides in a sense a single-epoch set of “tertiary standards” covering more than one quarter of the sky. Our transformations should facilitate their use to easily and reliably derive the corresponding approximate Johnson-Cousins or RGU magnitudes. Methods. The SDSS survey covers a number of areas that were previously established as standard fields in the Johnson-Cousins system, in particular, fields established by Landolt and by Stetson. We used these overlapping fields to create well-photometered star samples on which our calculated transformations are based. For the RGU photometry we used fields observed in the framework of the new Basel high-latitude field star survey. Results. We calculated empirical color transformations between SDSS photometry and Johnson-Cousins UBVRI and Becker's RGU system. For all transformations we found linear relations to be sufficient. Furthermore we showed that the transformations between the Johnson-Cousins and the SDSS system have a slight dependence on metallicity.