论文标题
睫毛膏-2 B的高分辨率传输光谱与Expres
High-resolution Transmission Spectroscopy of MASCARA-2 b with EXPRES
论文作者
论文摘要
我们使用新委托的Expres频谱仪获得的第一个过境观测值报告了在睫毛膏-2 B大气中对原子物种的检测。 Expres是一款高度稳定的光学梯形光谱仪，旨在检测幅度降低至30 cm/s的恒星反射运动，最近在Lowell Discovery望远镜上部署。通过使用互相关方法分析超热木星睫毛膏-2 B的传输光谱，我们确认了先前对Fe I，Fe II和Na I的检测，这些检测可能起源于膨胀大气的上部区域。此外，我们报告了MG I和CR II的大量检测。吸收强度随时间而变化略有变化，可能表明在日间和夜间终结者中的温度和化学反应不同。使用过渡行星引起的有效恒星线形变化，我们将系统的旋转轨道错位限制为$ 1.6 \ pm3.1 $度，与对齐的轨道一致。我们证明，ExpRES连接了一套能够进行外球星大气的相分辨光谱的仪器。
We report detections of atomic species in the atmosphere of MASCARA-2 b, using the first transit observations obtained with the newly commissioned EXPRES spectrograph. EXPRES is a highly stabilised optical echelle spectrograph, designed to detect stellar reflex motions with amplitudes down to 30 cm/s, and was recently deployed at the Lowell Discovery Telescope. By analysing the transmission spectrum of the ultra-hot Jupiter MASCARA-2 b using the cross-correlation method, we confirm previous detections of Fe I, Fe II and Na I, which likely originate in the upper regions of the inflated atmosphere. In addition, we report significant detections of Mg I and Cr II. The absorption strengths change slightly with time, possibly indicating different temperatures and chemistry in the day-side and night-side terminators. Using the effective stellar line-shape variation induced by the transiting planet, we constrain the projected spin-orbit misalignment of the system to $1.6\pm3.1$ degrees, consistent with an aligned orbit. We demonstrate that EXPRES joins a suite of instruments capable of phase-resolved spectroscopy of exoplanet atmospheres.
