Global optimization-based reference star differential imaging for high-contrast exoplanet imaging survey
Global optimization-based reference star differential imaging for high-contrast exoplanet imaging survey
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DOI：
10.1093/mnras/stab022
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发表时间：
2021-02
影响因子：
4.8
通讯作者：
D. Ren;Yili Chen
中科院分区：
文献类型：
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作者：
D. Ren;Yili Chen
我们提出了一种称为基于全局优化的参考星差成像（G-RDI）的数据简化方法，该方法可用于系外行星成像调查，其中来自同一年轻恒星协会的大量目标恒星被成像，并且不需要场旋转。我们的G-RDI的一个独特之处在于，我们从同一恒星协会的其他科学目标恒星中选择参考恒星，优化与目标恒星的高对比度成像，从而最大限度地提高了观测效率，并且在去除散斑噪声方面具有良好的性能，因此即使在与被成像的主恒星很小的内工作角（IWA）下也可以实现高对比度。我们提出的G-RDI在小IWA下进行了高对比度的系外行星成像优化，并提供了明显优于当前参考星差成像（RDI）方法的对比度。此外，我们还提出了多参考星的使用，并发现我们的G-RDI在这种情况下可以进一步提供更好的性能。将结果与其他系外行星数据约简技术（包括传统的RDI）进行了比较，结果表明，我们的两颗参考恒星的G-RDI可以显著提高在小型IWA下的对比性能，并具有较高的观测效率，这是当前数据约简技术无法提供的两个关键特征。该方法可用于赤道和其他方位角安装望远镜，并为未来在小型IWA上具有高观测效率的系外行星成像调查提供了新的选择。
We propose a data reduction approach called global optimization-based reference star differential imaging (G-RDI), which can be used for exoplanet imaging survey, where large numbers of target stars from the same young stellar association are imaged and where no field rotation is needed. One of the unique features of our G-RDI is that we select reference stars from other scientific target stars in the same stellar association to optimize for high-contrast imaging with a target star, which maximizes the observational efficiency and also delivers good performance to remove the speckle noise so that high contrast is achievable even at a small inner working angle (IWA) to the host star of being imaged. We proposed the G-RDI that is optimized for high-contrast exoplanet imaging at a small IWA and to provide a contrast that is significantly better than the current reference star differential imaging (RDI) method. In addition, we also propose the use of multiple reference stars and found that our G-RDI can further deliver better performance in that case. The result was compared with other exoplanet data reduction techniques, including the traditional RDI, and it indicated that our G-RDI with two reference stars can significantly improve the contrast performance at a small IWA with a high observational efficiency – two critical features that current data reduction techniques cannot offer. This approach could be used with both equatorial and alt-azimuth mount telescopes, and provides a new option for future exoplanet imaging surveys with high observational efficiency at a small IWA.