JHK-band spectro-interferometry of T Cep with the IOTA interferometer
JHK-band spectro-interferometry of T Cep with the IOTA interferometer
复制标题
使用 IOTA 干涉仪进行 T Cep 的 JHK 波段光谱干涉测量
DOI：
10.1117/12.458659
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
B. Yudin
中科院分区：
文献类型：
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作者：
G. Weigelt;U. Beckmann;J. Berger;T. Bloecker;M. Brewer;K. Hofmann;M. Lacasse;V. Malanushenko;R. Millan;J. Monnier;K. Ohnaka;E. Pedretti;D. Schertl;F. Schloerb;M. Scholz;W. Traub;B. Yudin
我们的新型IOTA JHK波段合束器允许同时记录光谱分散的J、H和K波段迈克尔逊干涉图。在本文中，我们提出了我们的IOTA观测的Mira星星T Cep与此光束组合器（2001年6月的意见，在14米至27米的范围内的四个基线）。光束组合器光学系统由变形柱面透镜系统和棱镜组成。从T Cep的干涉图中，我们导出了Vibrium和J、H、K波段均匀盘的直径分别为14.0 ± 0.6、13.7 ± 0.6和15.0 ± 0.6质量。通过拟合不同Mira星星模型的理论中心-边缘强度变化（CLV），从实测的Vibrance出发，导出了恒星角滤波半径和Rosseland半径。T Cep的有效HIPPARCOS视差（4.76 ± 0.75 mas）允许我们确定线性半径。例如，如果我们使用M模型的CLV作为拟合函数，那么从K波段可见度我们得到329-50/+70太阳半径的Rosseland半径。这个半径与M模型的罗塞兰半径（315个太阳半径）非常吻合。测量的恒星参数（如直径，有效温度，可见度形状）与理论参数的比较表明，是否有任何模型是一个公平的代表T Cep。不同光谱通道的光谱比值比绝对光谱比值的测量精度更高。因此，我们使用可见度比V（λ1）/V（λ2）来研究恒星直径的波长依赖性。我们发现2.03 μm的T Cep均匀盘直径比2.26 μm的均匀盘直径大1.26倍。
Our new IOTA JHK-band beam combiner allows the simultaneous recording of spectrally dispersed J-, H- and K-band Michelson interferograms. In this paper we present our IOTA observations of the Mira star T Cep with this beam combiner (observations in June 2001; four baselines in the range of 14 m to 27 m). The beam combiner optics consists of an anamorphic cylindrical lens system and a prism. From the interferograms of T Cep we derive the visibilities and the J-, H-, and K-band uniform-disk diameters of 14.0 ± 0.6 mas, 13.7 ± 0.6 mas and 15.0 ± 0.6 mas, respectively. Angular stellar filter radii and Rosseland radii are derived from the measured visibilities by fitting theoretical center-to-limb intensity variations (CLVs) of different Mira star models. The available HIPPARCOS parallax (4.76 ± 0.75 mas) of T Cep allows us to determine linear radii. For example, from the K-band visibility we derive a Rosseland radius of 329-50/+70 solar radii if we use the CLVs of the M-models as fit functions. This radius is in good agreement with the theoretical M-model Rosseland radius of 315 solar radii. The comparison of measured stellar parameters (e.g. diameters, effective temperature, visibility shape) with theoretical parameters indicates whether any of the models is a fair representation of T Cep. The ratios of visibilities of different spectral channels can be measured with higher precision than absolute visibilities. Therefore, we use the visibility ratios V(λ1)/V(λ2) to investigate the wavelength dependence of the stellar diameter. We find that the 2.03 μm uniform-disk diameter of T Cep is about 1.26 times larger than the 2.26 μm uniform-disk diameter.