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arXiv 0803.0674astro-ph
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在银河系低纬度解开银河系

Disentangling the Galaxy at low Galactic latitudes

M. Cignoni, M. Tosi, A. Bragaglia, J. S. Kalirai, D. S. Davis

摘要:

我们利用BOCCE的疏散星团巡天的场星,研究了加拿大-法国-夏威夷望远镜(CFHT)拍摄的三个低纬度场,目的是更好地了解这些方向上的银河系结构。由于在这些领域的深入和准确的测光,他们提供了一个强大的判别银河系结构模型。在本文中,我们讨论了一个典型的恒星计数模型,表示在薄和厚盘径向尺度,厚盘归一化和红化分布,可以解释所观察到的CMD。圆盘和厚圆盘用双指数描述,球体用De Vaucouleurs密度定律描述。为了评估一组特定参数的拟合质量,将合成测光的颜色分布和光度函数与从观测到的颜色-星等图的蓝色序列中选择的目标星的颜色分布和光度函数进行比较。通过Kolmogorov-Smirnov检验,我们发现经典的分解halo-thin/thick disc足以重现观测结果-没有额外的人口是严格必要的。根据所有三个领域的共同解决方案,我们已经发现了一个厚盘规模的长度等于(或略长于)薄盘规模。

英文摘要:

We have used the field stars from the open cluster survey BOCCE, to study three low-latitude fields imaged with the Canada-France-Hawaii telescope (CFHT), with the aim of better understanding the Galactic structure in those directions. Due to the deep and accurate photometry in these fields, they provide a powerful discriminant among Galactic structure models. In the present paper we discuss if a canonical star count model, expressed in terms of thin and thick disc radial scales, thick disc normalization and reddening distribution, can explain the observed CMDs. Disc and thick disc are described with double exponentials, the spheroid is represented with a De Vaucouleurs density law. In order to assess the fit quality of a particular set of parameters, the colour distribution and luminosity function of synthetic photometry is compared to that of target stars selected from the blue sequence of the observed colour-magnitude diagrams. Through a Kolmogorov-Smirnov test we find that the classical decomposition halo-thin/thick disc is sufficient to reproduce the observations--no additional population is strictly necessary. In terms of solutions common to all three fields, we have found a thick disc scale length that is equal to (or slightly longer than) the thin disc scale.

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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