论文标题
WASP-7 B带uves的传输光谱 - 检测Na I D $ _2 $和暂定d $ _1 $ line Line吸收
Transmission spectroscopy of WASP-7 b with UVES -- Detection of Na I D$_2$ and tentative D$_1$ line absorption
论文作者
论文摘要
传输光谱是研究跨界大气的化学组成和结构的主要技术。在热木星的过渡过程中，在光学NA I D1中检测到了强大的吸收信号，这归因于行星大气，并使我们能够约束其结构。我们通过钠线中的高分辨率过境光谱研究WASP-7 B的大气。我们分析了使用Ultraviolet和Visual Echelle光谱仪（UVE）观察到的热木星WASP-7 B的89个高分辨率光谱的光谱传输时间序列。我们使用了矫尿线来准确地对齐光谱，并用分子进行矫正。通过研究诸如Ca II H和K和氢H $α$线等色谱线的恒星磁活性。最后，我们获得了各种线路的传输光谱和光曲线。该恒星没有可识别的耀斑，如果有的话，在我们观察到的跑步期间活动的边际变化。钠透射光谱和相应的光曲线清楚地显示了我们使用合成光谱进行建模的Rossiter-McLaughlin效应（RM）和恒星中心对中的变化（CLV）。具有0.50 $ \ pm的线对比度为0.06％（$ \ sim8.3σ$级别）的线对比度为0.50 $ \ pm的统计学意义，狭窄的吸收功能，并在NA I D $ _2 $的位置上检测到一个最高（FWHM）0.13 $ \ pm 0.02 a的完整宽度。对于NA I D $ _1 $线信号，我们得出了一个0.13 $ \ pm $ 0.04％（以$ \ sim3.2σ$ Level）的对比度，我们认为这是一个暂定的检测。此外，我们还提供了氢Balmer系列（H $α$，H $β$和H $γ$），K I $λ$ 7699 A，Ca II H和K的吸收上限。
Transmission spectroscopy is a prime technique to study the chemical composition and structure of exoplanetary atmospheres. Strong excess absorption signals have been detected in the optical Na I D1, 2 Fraunhofer lines during transits of hot Jupiters, which are attributed to the planetary atmospheres and allow us to constrain its structure. We study the atmosphere of WASP-7 b by means of high-resolution transit spectroscopy in the sodium lines. We analyzed a spectral transit time series of 89 high-resolution spectra of the hot Jupiter WASP-7 b that was observed using the Ultraviolet and Visual Echelle Spectrograph (UVES). We used the telluric lines for an accurate alignment of the spectra and carry out a telluric correction with molecfit. Stellar magnetic activity was monitored by investigating chromospheric lines such as the Ca II H and K and hydrogen H$α$ lines. Finally, we obtained transmission spectra and light curves for various lines. The star shows no identifiable flares and, if any, marginal changes in activity during our observing run. The sodium transmission spectra and corresponding light curves clearly show signs of the Rossiter-McLaughlin effect (RM) and the stellar center-to-limb variation (CLV) that we modeled using synthetic spectra. A statistically significant, narrow absorption feature with a line contrast of 0.50$\pm$0.06% (at $\sim 8.3σ$ level) and a full width at half maximum (FWHM) of 0.13$\pm$0.02 A is detected at the location of the Na I D$_2$ line. For the Na I D$_1$ line signal, we derived a line contrast of 0.13$\pm$0.04% (at $\sim 3.2σ$ level), which we consider a tentative detection. In addition, we provide upper limits for absorption by the hydrogen Balmer lines (H$α$, H$β$, and H$γ$), K I $λ$7699 A, Ca II H and K, and infra-red triplet (IRT) lines.
