论文标题
访问：在黄蜂31b的大气中确认没有钾
ACCESS: Confirmation of no potassium in the atmosphere of WASP-31b
论文作者
论文摘要
我们提出了热木星黄蜂31b的新光学（400-950nm）传输光谱（M = 0.48 MJ; r = 1.54 rj; p = 3.41天），通过组合四个Transits观测来获得。在Las Campanas天文台的Magellan Baade望远镜上观察到这些转移，这是通道项目的一部分。我们研究了这个星球上层大气中的云/危险，以及恒星活动对观察到的特征的贡献。此外，我们搜索了碱性元素Na I和K I的吸收特征，特别关注K I，为此有两个先前出版的不同意结果。用HST/STIS检测到的观察结果被检测到K I，而地面的低分辨率和高分辨率观察结果却没有。我们使用平衡和非平衡化学检索来探索系统的行星和恒星参数空间，并结合现有的近IR观测值。我们最适合的模型是，散射坡度与雷利斜率（Alpha = 5.3+2.9-3.1）一致，在原木云上压力为-3.6+2.7-2.1 bar上的高蓝色云以及可能的H2O特征。我们发现，我们的观察结果支持其他基于k的基于地面的主张。然后，我们将麦哲伦/iMac的传输频谱与现有的VLT/FORS2，HST/WFC3，HST/STIS和Spitzer观测并置，以进一步限制行星的光学到红外大气特征。我们发现，较陡的散射坡度（alpha = 8.3 +/- 1.5）由dembengths bluewards锚定为400 nm，只有原始的性传播性观测值显示出明显的钾信号。
We present a new optical (400-950nm) transmission spectrum of the hot Jupiter WASP-31b (M=0.48 MJ; R= 1.54 RJ; P=3.41 days), obtained by combining four transits observations. These transits were observed with IMACS on the Magellan Baade Telescope at Las Campanas Observatory as part of the ACCESS project. We investigate the presence of clouds/hazes in the upper atmosphere of this planet as well as the contribution of stellar activity on the observed features. In addition, we search for absorption features of the alkali elements Na I and K I, with particular focus on K I, for which there have been two previously published disagreeing results. Observations with HST/STIS detected K I, whereas ground-based low- and high-resolution observations did not. We use equilibrium and non-equilibrium chemistry retrievals to explore the planetary and stellar parameter space of the system with our optical data combined with existing near-IR observations. Our best-fit model is that with a scattering slope consistent with a Rayleigh slope (alpha=5.3+2.9-3.1), high-altitude clouds at a log cloud top pressure of -3.6+2.7-2.1 bars, and possible muted H2O features. We find that our observations support other ground-based claims of no K I. Clouds are likely why signals like H2O are extremely muted and Na or K cannot be detected. We then juxtapose our Magellan/IMACS transmission spectrum with existing VLT/FORS2, HST/WFC3, HST/STIS, and Spitzer observations to further constrain the optical-to-infrared atmospheric features of the planet. We find that a steeper scattering slope (alpha = 8.3+/-1.5) is anchored by STIS wavelengths blueward of 400 nm and only the original STIS observations show significant potassium signal.
