The VMC survey - VIII : First results for anomalous Cepheids
The VMC survey - VIII : First results for anomalous Cepheids
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DOI：
10.1093/mnras/stt2047
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发表时间：
2013-10
影响因子：
4.8
通讯作者：
V. Ripepi;M. Marconi;M. Moretti;G. Clementini;M. Cioni;R. Grijs;J. Emerson;M. Groenewegen
中科院分区：
文献类型：
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作者：
V. Ripepi;M. Marconi;M. Moretti;G. Clementini;M. Cioni;R. Grijs;J. Emerson;M. Groenewegen
麦哲伦云系的VISTA近红外Y JK巡天（VMC，PI M.- R. L. Cioni）正在收集由两个麦哲伦云和连接它们的桥形成的系统中的脉动变星的深KS波段时间序列测光。在本文中，我们提出了第一次KS波段光变曲线的异常造父变星（AC）。特别是，我们分析了48个大麦哲伦云AC的样本，其识别和光学星等从OGLE III和IV目录中获得。VMC KS波段光变曲线的AC采样良好，时代的数量范围从8到16，并允许我们获得非常精确的平均Ks幅度与误差的顺序平均为0.01马格。的hKsi值被用来建立第一个周期亮度和周期Weseneirs的关系在近红外的基本模式和第一泛音AC。同时，我们利用光学（V，I）OGLE数据建立了基模和第一泛音AC的精确周期-亮度，周期-亮度-颜色和周期-韦森森关系。第一次，这些关系是来自一个样本的均匀覆盖整个AC不稳定带的振荡器。应用光学周期Wesenlavian关系的样本矮星系托管的AC显着的人口显示，这种关系是一个有价值的工具，用于推导距离内的本地集团。由于其较低的色散，我们希望在本文中首次推导出的Ks周期-Weseneirs关系代表一个有价值的工具，用于测量准确的距离，星系托管AC时，更多的数据在近红外滤波器变得可用。
The VISTA near-infrared Y JKs survey of the Magellanic Clouds System (VMC, PI M.-R. L. Cioni) is collecting deep Ks–band time–series photometry of the pulsating variable stars hosted in the system formed by the two Magellanic Clouds and the Bridge connecting them. In this paper we present for the first time Ks–band light curves for Anomalous Cepheid (AC) variables. In particular, we have analysed a sample of 48 Large Magellanic Cloud ACs, for which identification and optical magnitudes were obtained from the OGLE III and IV catalogues. The VMC Ks–band light curves for ACs are well sampled, with the number of epochs ranging from 8 to 16, and allowing us to obtain very precise mean Ks magnitudes with errors on average of the order of 0.01 mag. The hKsi values were used to build the first Period–Luminosity and Period–Wesenheit relations in the near-infrared for fundamental-mode and first overtone ACs. At the same time we exploited the optical (V,I) OGLE data to build accurate Period–Luminosity, Period–Luminosity–Colour and Period-Wesenheit relations both for fundamental-mode and first overtone ACs. For the first time these relations were derived from a sample of pulsators which uniformly cover the whole AC instability strip. The application of the optical Period–Wesenheit relation to a sample of dwarf galaxies hosting a significant population of ACs revealed that this relation is a valuable tool for deriving distances within the Local Group. Due to its lower dispersion, we expect the Ks Period–Wesenheit relations first derived in this paper to represent a valuable tool for measuring accurate distances to galaxies hosting ACs when more data in near-infrared filters become available.