标题： 大麦哲伦云星团中的红巨星 显示英文标题

标题： Red Giant stars in the Large Magellanic Cloud clusters

摘要： 我们提供了大麦哲伦云中13个球状星团的深度J、H、Ks测光数据和精确的颜色-亮度图，直到K ~18.5。这个数据集与我们小组之前发表的6个星团的数据样本相结合，为我们研究不同年龄（从~80百万年到~35亿年）的星团中的巨星性质提供了机会。 我们得到了渐近巨星分支、红巨星分支和氦团簇中恒星群体数量和亮度比例的定量估计，并将其与理论模型进行了比较，以探测所谓的相变。 渐近巨星分支对总光度的贡献在~200百万年时开始显著，在RGB相变开始时达到最大值(~5-600百万年)。 在~900百万年时，扩展且人口密集的红巨星分支已经完全发育。 AGB和RGB相变的发生都是短暂事件，仅持续几百万年。 这些经验结果与基于标准轨道和燃料消耗方法的简单恒星群体模型的理论预测非常吻合。 显示英文摘要

摘要： We present deep J,H,Ks photometry and accurate Color Magnitude Diagrams down to K ~18.5, for a sample of 13 globular clusters in the Large Magellanic Cloud. This data set combined with the previous sample of 6 clusters published by our group gives the opportunity to study the properties of giant stars in clusters with different ages (ranging from ~80 Myr up to ~3.5 Gyr). Quantitative estimates of star population ratios (by number and luminosity) in the Asymptotic Giant Branch, the Red Giant Branch and the He-clump, have been obtained and compared with theoretical models in the framework of probing the so-called phase transitions. The AGB contribution to the total luminosity starts to be significant at ~200 Myr and reaches its maximum at ~5-600 Myr, when the RGB Phase Transition is starting. At ~900 Myr the full developing of an extended and well populated RGB has been completed. Both the occurrence of the AGB and RGB Phase Transitions are sharp events, lasting a few hundreds Myr only. These empirical results agree very well with the theoretical predictions of simple stellar population models based on canonical tracks and the fuel-consumption approach.