Spatio-spectral encoding of fringes in optical long-baseline interferometry - Example of the 3T and 4T recombining mode of VEGA/CHARA
Spatio-spectral encoding of fringes in optical long-baseline interferometry - Example of the 3T and 4T recombining mode of VEGA/CHARA
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光学长基线干涉测量中条纹的空间光谱编码 - VEGA/CHARA 的 3T 和 4T 重组模式示例
DOI：
10.1051/0004-6361/201116976
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发表时间：
2011
影响因子：
6.5
通讯作者：
J. Monnier
中科院分区：
文献类型：
--
作者：
D. Mourard;P. Bério;K. Perraut;R. Ligi;A. Blazit;J. Clausse;N. Nardetto;A. Spang;I. Tallon;D. Bonneau;O. Chesneau;O. Delaa;F. Millour;P. Stee;J. L. Bouquin;T. Brummelaar;C. Farrington;P. J. Goldfinger;J. Monnier
上下文光学恒星干涉仪的主要挑战之一是增加重组单元中的望远镜数量，以提供更多的测量和改进的成像能力。与此同时，需要保留光谱能力，这导致复杂的重组方案，可能会抑制发展。目标。我们描述的可能性相结合的空间和光谱编码的条纹更紧凑的光束组合器的设计和最小化必须读取的像素的数量。方法.我们建立了空间光谱条纹编码的形式主义，讨论了一般的应用，并描述了在3 T/4 T观测模式的VEGA（可见spEctroGraph和polArimeter）仪器安装在相干焦点的CHARA阵列位于威尔逊山在加州的实施。最后，我们提出了科学的情况下，可能通过这种工具的实施VEGA/CHARA的情况下。结果我们证明了在多望远镜光束组合器中实现条纹的优化空间光谱编码的兴趣。在天空中的结果，获得与3 T模式的VEGA组合器。在可见光波段和CHARA的百米基线下，亚质量恒星直径可以用5000的光谱分辨率以百分之几的精度确定。我们的第一次估计的封闭阶段表明，精度优于1度，可以实现。结论.采用空间光谱条纹编码的3 T-4 T VEGA仪器获得的第一个天空结果表明，在未来的复杂光束组合器的设计中使用该原理的有效性。
Context. One of the main challenges of optical stellar interferometers is to increase the number of telescopes in the recombining unit to provide a larger number of measurements and an improved imaging capability. At the same time there is a need to preserve the spectroscopic capabilities, which leads to complex recombining schemes that may inhibit development. Aims. We describe the possibilities of combining the spatial and spectral encoding of fringes for the design of more compact beam combiners and for minimizing the number of pixels that must be read. Methods. We establish the formalism of the spatio-spectral fringe encoding, discuss general applications, and describe an implementation in the 3T/4T observing mode of the VEGA (Visible spEctroGraph and polArimeter) instrument installed at the coherent focus of the CHARA Array located on Mt Wilson in California. We finally present the science cases made possible by this instrumental implementation in the case of VEGA/CHARA. Results. We demonstrate the interest in implementing an optimized spatio-spectral encoding of fringes in a multi-telescope beam combiner. On-sky results, obtained with the 3T mode of the VEGA combiner are presented. At visible wavelengths and with the hectometric baselines of CHARA, sub-mas stellar diameters could be determined with a precision of a few percent with a spectral resolution of 5000. Our first estimates of closure phase show that accuracies better than 1 degree can be achieved. Conclusions. The first on-sky results obtained with the 3T-4T VEGA instrument using spatio-spectral fringe encoding show the validity of using this principle in the design of future complex beam combiners.