Searching for reflected light from τ Bootis b with high-resolution ground-based spectroscopy : Approaching the 10-5 contrast barrier
Searching for reflected light from τ Bootis b with high-resolution ground-based spectroscopy : Approaching the 10-5 contrast barrier
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使用高分辨率地面光谱搜索 τ Bootis b 的反射光：接近 10-5 对比屏障
DOI：
10.1051/0004-6361/201731192
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发表时间：
2017
影响因子：
6.5
通讯作者：
S. V. Terwisga
中科院分区：
文献类型：
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作者：
H. J. Hoeijmakers;I. Snellen;S. V. Terwisga
语境。由于系外行星与主恒星的反差极大，测量系外行星反射的星光具有挑战性。对于热木星，这种对比度在 10 -6 到 10 -4 范围内，具体取决于它们的反照率、半径和轨道距离。自从发现第一颗热木星以来，人们就一直在进行反射光搜索，但成果非常有限，因为热木星由于普遍缺乏反射云层而往往具有较低的反照率值。目的。这项研究的目的是寻找来自 τ Boo b 的反射光，这是一颗拥有最亮主星之一的热木星。自 1997 年被发现以来，它一直是利用高色散光谱进行反射光搜索的对象。在这里，我们的目标是将这些数据合并到一个荟萃分析中。方法。我们分析了 1998 年至 2013 年间各个时期使用 UVES、ESPaDOnS、NARVAL UES 和 HARPS-N 摄谱仪获得的 2000 多个档案高色散光谱。每个光谱首先清除了恒星光谱，然后与 PHOENIX 模型光谱进行互相关。然后，这些信号被多普勒移至行星静止坐标系，并及时共同添加，并根据行星信号的预期信噪比进行加权。结果。我们达到了行星与恒星对比度的 3 σ 上限，即 1.5 × 10 -5 。假设行星半径为 1.15 R J ，这对应于 400-700 nm 之间的光学反照率。低反照率与使用太空天文台对其他热木星的次食和相位曲线观测以及对其反射特性的理论预测一致。
Context. It is challenging to measure the starlight reflected from exoplanets because of the extreme contrast with their host stars. For hot Jupiters, this contrast is in the range of 10 −6 to 10 −4 , depending on their albedo, radius and orbital distance. Searches for reflected light have been performed since the first hot Jupiters were discovered, but with very limited success because hot Jupiters tend to have low albedo values due to the general absence of reflective cloud decks. Aim. The aim of this study is to search for reflected light from τ Boo b, a hot Jupiter with one of the brightest host stars. Since its discovery in 1997, it has been the subject of several reflected-light searches using high-dispersion spectroscopy. Here we aim to combine these data in to a single meta-analysis. Methods. We analysed more than 2000 archival high-dispersion spectra obtained with the UVES, ESPaDOnS, NARVAL UES and HARPS-N spectrographs during various epochs between 1998 and 2013. Each spectrum was first cleaned of the stellar spectrum and subsequently cross-correlated with a PHOENIX model spectrum. These were then Doppler shifted to the planet rest-frame and co-added in time, weighted according to the expected signal-to-noise of the planet signal. Results. We reach a 3 σ upper limit of the planet-to-star contrast of 1.5 × 10 −5 . Assuming a planet radius of 1.15 R J , this corresponds to an optical albedo of between 400–700 nm. A low albedo is in line with secondary eclipse and phase curve observations of other hot Jupiters using space-based observatories, as well as theoretical predictions of their reflective properties.
影响因子：
6.5
作者：
D. Gandolfi;H. Parviainen;M. Fridlund;A. Hatzes;H. Deeg;A. Frasca;Antonino Francesco Lanza;P. Moroni;E. Tognelli;A. McQuillan;S. Aigrain;R. Alonso;V. Antoci;J. Cabrera;L. Carone;S. Csizmadia;A. A. Djupvik-A.;E. Guenther;J. Jessen-Hansen;A. Ofir;J. Telting
通讯作者：
D. Gandolfi;H. Parviainen;M. Fridlund;A. Hatzes;H. Deeg;A. Frasca;Antonino Francesco Lanza;P. Moroni;E. Tognelli;A. McQuillan;S. Aigrain;R. Alonso;V. Antoci;J. Cabrera;L. Carone;S. Csizmadia;A. A. Djupvik-A.;E. Guenther;J. Jessen-Hansen;A. Ofir;J. Telting
HD 189733 的夫琅和费线的中心到肢体的变化；
DOI：
10.1051/0004-6361/201526386
发表时间：
2015
期刊：
arXiv: Solar and Stellar Astrophysics
影响因子：
--
作者：
Czesla
通讯作者：
Czesla