论文标题
高斯过程框架的应用用于建模高分辨率系外行星光谱
Applications of a Gaussian Process Framework for Modelling of High-Resolution Exoplanet Spectra
论文作者
论文摘要
尽管与地面观测相关的问题，但对高分辨率的外球星大气的观察有可能解决单个行星吸收线。去除污染的恒星和矫尿吸收特征是揭示行星光谱所需的最敏感的步骤之一，尽管存在许多不同的降低方法，但仍然很难直接比较这些方法的性能和效率。此外，尽管标准互相关方法可以强大地检测特定的大气物种，但仅对预期的特征进行探测。在这里，我们提出了一种使用高斯过程（GP）回归的新方法，以直接对高分辨率光谱的组成部分进行建模，该方法部分解决了这些问题。 We use two archival CRIRES/VLT data sets as test cases, observations of the hot Jupiters HD 189733 b and 51 Pegasi b, recovering injected signals with average line contrast ratios of $\sim 4.37 \times 10^{-3}$ and $\sim 1.39 \times 10^{-3}$, and planet radial velocities $ΔK_\ MATHRM {p} = 1.45 \ pm 1.53 \，\ Mathrm {km \，s^{ - 1}} $和$ΔK_\ Mathrm {p} = 0.12 \ pm pm pm pm pm0.12 \ pm，\ m m ionsrm {此外，我们通过实施注射回收测试来证明GP方法的应用来评估登出过程对行星光谱的影响。我们表明，文献中使用的标准下降方法尤其会对吸收特征的振幅产生负面影响，这有可能使检索分析不准确。最后，我们讨论了使用此方法的非检测因素的可能限制因素，可能会通过更高的信噪数据来补救。
Observations of exoplanet atmospheres in high resolution have the potential to resolve individual planetary absorption lines, despite the issues associated with ground-based observations. The removal of contaminating stellar and telluric absorption features is one of the most sensitive steps required to reveal the planetary spectrum and, while many different detrending methods exist, it remains difficult to directly compare the performance and efficacy of these methods. Additionally, though the standard cross-correlation method enables robust detection of specific atmospheric species, it only probes for features that are expected a priori. Here we present a novel methodology using Gaussian process (GP) regression to directly model the components of high-resolution spectra, which partially addresses these issues. We use two archival CRIRES/VLT data sets as test cases, observations of the hot Jupiters HD 189733 b and 51 Pegasi b, recovering injected signals with average line contrast ratios of $\sim 4.37 \times 10^{-3}$ and $\sim 1.39 \times 10^{-3}$, and planet radial velocities $ΔK_\mathrm{p} =1.45 \pm 1.53\,\mathrm{km\,s^{-1}}$ and $ΔK_\mathrm{p}=0.12\pm0.12\,\mathrm{km\,s^{-1}}$ from the injection velocities respectively. In addition, we demonstrate an application of the GP method to assess the impact of the detrending process on the planetary spectrum, by implementing injection-recovery tests. We show that standard detrending methods used in the literature negatively affect the amplitudes of absorption features in particular, which has the potential to render retrieval analyses inaccurate. Finally, we discuss possible limiting factors for the non-detections using this method, likely to be remedied by higher signal-to-noise data.
