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arXiv 0903.5302astro-ph.IMastro-ph.SR
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Stellar Locus Regression:精确的颜色定标和实时测定星系团光度红移

Stellar Locus Regression: Accurate Color Calibration, and the Real-time Determination of Galaxy Cluster Photometric Redshifts

F. William High, Christopher W. Stubbs, Armin Rest, Brian Stalder, Peter Challis

摘要:

我们提出恒星轨迹回归(SLR),直接调整仪器的宽带光学颜色的恒星,使它们符合一个通用的恒星颜色的轨迹,产生精确校准的颜色为恒星和星系的方法。这是在没有首先为每个通带建立单独零点的情况下实现的,并且可以在望远镜处实时执行。我们演示了SLR如何自然地对仪器响应的差异,大气透明度,大气消光和银河系消光进行一次批发校正。我们进行了一个例子SLR处理SDSS数据在很宽的范围内的银河尘埃值和独立恢复的方向和幅度的典型的银河系红化矢量与14- 18毫等RMS的不确定性。然后,我们隔离的影响,大气消光,表明,SLR帐户,这和返回精确的颜色在广泛的气团,与5- 14毫等RMS残差。我们证明,SLR校正的颜色是足够准确的,允许光度红移估计的星系团(使用红色序列星系)的不确定性sigma_z/(1+z)= 0.6%,每个星系团的红移0.09<z<0.25。最后,我们确定我们的对象在2 MASS的全天空目录,并产生i波段零点通常精确到18毫等只使用SLR。我们提供对IDL例程的开放源代码访问,并验证了该技术的实现,网址为http://stellar-locus-regression.googlecode.com

英文摘要:

We present Stellar Locus Regression (SLR), a method of directly adjusting the instrumental broadband optical colors of stars to bring them into accord with a universal stellar color-color locus, producing accurately calibrated colors for both stars and galaxies. This is achieved without first establishing individual zeropoints for each passband, and can be performed in real-time at the telescope. We demonstrate how SLR naturally makes one wholesale correction for differences in instrumental response, for atmospheric transparency, for atmospheric extinction, and for Galactic extinction. We perform an example SLR treatment of SDSS data over a wide range of Galactic dust values and independently recover the direction and magnitude of the canonical Galactic reddening vector with 14--18 mmag RMS uncertainties. We then isolate the effect of atmospheric extinction, showing that SLR accounts for this and returns precise colors over a wide of airmass, with 5--14 mmag RMS residuals. We demonstrate that SLR-corrected colors are sufficiently accurate to allow photometric redshift estimates for galaxy clusters (using red sequence galaxies) with an uncertainty sigma_z/(1+z) = 0.6% per cluster for redshifts 0.09<z<0.25. Finally, we identify our objects in the 2MASS all-sky catalog, and produce i-band zeropoints typically accurate to 18 mmag using only SLR. We offer open-source access to our IDL routines, validated and verified for the implementation of this technique, at http://stellar-locus-regression.googlecode.com

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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