INVERTING COLOR–MAGNITUDE DIAGRAMS TO ACCESS PRECISE STAR CLUSTER PARAMETERS: A NEW WHITE DWARF AGE FOR THE HYADES
INVERTING COLOR–MAGNITUDE DIAGRAMS TO ACCESS PRECISE STAR CLUSTER PARAMETERS: A NEW WHITE DWARF AGE FOR THE HYADES
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DOI：
10.1088/0004-637x/696/1/12
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发表时间：
2009-04
期刊：
影响因子：
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通讯作者：
S. DeGennaro;T. von Hippel;W. Jefferys;N. Stein;D. V. van Dyk;E. Jeffery
中科院分区：
文献类型：
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作者：
S. DeGennaro;T. von Hippel;W. Jefferys;N. Stein;D. V. van Dyk;E. Jeffery
我们已经扩展了我们的星团贝叶斯模型-它使用主序恒星演化模型，初始质量和白矮星(WD)质量之间的映射，WD冷却模型，WD大气-包括双星，场星，和另外两个主序恒星演化模型。作为对我们的贝叶斯建模技术的关键测试，我们将其应用于Hyade UBV测光，成员资格先验基于自身运动和径向速度(如果可用)。在一组特定的WD冷却模式和大气模式的假设下，我们根据冷却WDS估算了毕星座的年龄为648±45Myr，这与Perryman等人对星系团主序关闭(MSTO)年龄的最佳先验分析一致。由于最微弱的WD很可能已经从土卫六蒸发掉了，以前的工作只提供了该星系团WD年龄的下限。我们的结果证明了明亮的WD技术在得出年龄方面的能力，并进一步证明了WD冷却和MSTO年龄之间的完全年龄一致性，到目前为止分析的七个星系团中的七个，范围从150Myr到4Gyr。
We have extended our Bayesian modeling of stellar clusters—which uses main-sequence stellar evolution models, a mapping between initial masses and white dwarf (WD) masses, WD cooling models, and WD atmospheres—to include binary stars, field stars, and two additional main-sequence stellar evolution models. As a critical test of our Bayesian modeling technique, we apply it to Hyades UBV photometry, with membership priors based on proper motions and radial velocities, where available. Under the assumption of a particular set of WD cooling models and atmosphere models, we estimate the age of the Hyades based on cooling WDs to be 648 ± 45 Myr, consistent with the best prior analysis of the cluster main-sequence turnoff (MSTO) age by Perryman et al. Since the faintest WDs have most likely evaporated from the Hyades, prior work provided only a lower limit to the cluster's WD age. Our result demonstrates the power of the bright WD technique for deriving ages and further demonstrates complete age consistency between WD cooling and MSTO ages for seven out of seven clusters analyzed to date, ranging from 150 Myr to 4 Gyr.