New distances to RAVE stars
New distances to RAVE stars
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DOI：
10.1093/mnras/stt1896
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发表时间：
2013-09
影响因子：
4.8
通讯作者：
J. Binney;B. Burnett;G. Kordopatis;P. McMillan;Sanjib Sharma;T. Zwitter;O. Bienaymé;J. Bland-Hawthorn-J.
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文献类型：
--
作者：
J. Binney;B. Burnett;G. Kordopatis;P. McMillan;Sanjib Sharma;T. Zwitter;O. Bienaymé;J. Bland-Hawthorn-J.
概率密度函数 (pdf) 是根据恒星距离模量的新恒星参数确定的，径向速度实验 (RAVE) 已经获得了 S/N >= 10 的光谱。单高斯拟合距离模量的 pdf 足以满足大约一半恒星的需求，而另一半中的大多数恒星具有令人满意的二高斯表示。正如预期的那样，早期型恒星很少需要超过一个高斯。距离期望值大于距离模期望所隐含的距离；后者本身大于视差期望值所暗示的距离。我们对依巴谷恒星的视差与依巴谷测量的值非常吻合，因此视差的期望是最可靠的距离指标。后者通过考虑消光而得到改善。当使用这些 pdf 来制作图表时，我们恒星的有效温度-绝对星等图得到了显着改善。我们使用 Schonrich、Binney 和 Asplund 设计的运动学校正方法来检查一般恒星的系统误差，并确认最可靠的距离指标是视差期望。对于冷矮星和低重力巨星，往往比真实距离大 30%。最令人满意的距离是温度高于 5500 K 的矮星。我们将我们与 13 个疏散星团中恒星的距离与文献中的星团距离进行了比较，发现矮星的距离非常一致，并表明我们高估了与巨星的距离，尤其是在年轻的星团中。
Probability density functions (pdfs) are determined from new stellar parameters for the distance moduli of stars for which the RAdial Velocity Experiment (RAVE) has obtained spectra with S/N >= 10. Single-Gaussian fits to the pdf in distance modulus suffice for roughly half the stars, with most of the other half having satisfactory two-Gaussian representations. As expected, early-type stars rarely require more than one Gaussian. The expectation value of distance is larger than the distance implied by the expectation of distance modulus; the latter is itself larger than the distance implied by the expectation value of the parallax. Our parallaxes of Hipparcos stars agree well with the values measured by Hipparcos, so the expectation of parallax is the most reliable distance indicator. The latter are improved by taking extinction into account. The effective temperature-absolute magnitude diagram of our stars is significantly improved when these pdfs are used to make the diagram. We use the method of kinematic corrections devised by Schonrich, Binney and Asplund to check for systematic errors for general stars and confirm that the most reliable distance indicator is the expectation of parallax. For cool dwarfs and low-gravity giants, tends to be larger than the true distance by up to 30 per cent. The most satisfactory distances are for dwarfs hotter than 5500 K. We compare our distances to stars in 13 open clusters with cluster distances from the literature and find excellent agreement for the dwarfs and indications that we are overestimating distances to giants, especially in young clusters.