论文标题
与JWST NIRSPEC PRISM的系外行星WASP-39B的早期发行科学
Early Release Science of the exoplanet WASP-39b with JWST NIRSpec PRISM
论文作者
论文摘要
系外行星的传输光谱揭示了几十个系外行星大气中的水蒸气，气溶胶和碱金属的特征。然而，这些先前对哈勃和spitzer空间望远镜的推论受到了观察结果相对狭窄的波长范围和光谱分辨能力的阻碍，这阻碍了对其他化学物质$ - $尤其是原代碳分子的明确鉴定。在这里，我们报告了一个宽波长0.5-5.5 $ $ m M的大气变速器频谱，其1200 K，1200 K，大致是土星质量，Jupiter-Radius Exoplanet，以JWST NIRSPEC的PRISM模式进行测量，作为JWST TransIting Exoplanet社区早期发行科学科学团队的一部分。我们强劲地检测到多种化学物种，包括Na（19 $σ$），H $ _2 $ O（33 $σ$），CO $ _2 $（28 $σ$）和CO（7 $σ$）。 Ch $ _4 $的未检测，结合强大的$ _2 $功能，有利于具有超实大气金属性的大气模型。 $ _2 $（2.7 $σ$）最好地解释了4 $μ$ m的意外吸收功能，这可能是大气光化学的示踪剂。这些观察结果表明了JWST对系外行星组成和化学过程的敏感性。
Transmission spectroscopy of exoplanets has revealed signatures of water vapor, aerosols, and alkali metals in a few dozen exoplanet atmospheres. However, these previous inferences with the Hubble and Spitzer Space Telescopes were hindered by the observations' relatively narrow wavelength range and spectral resolving power, which precluded the unambiguous identification of other chemical species$-$in particular the primary carbon-bearing molecules. Here we report a broad-wavelength 0.5-5.5 $μ$m atmospheric transmission spectrum of WASP-39 b, a 1200 K, roughly Saturn-mass, Jupiter-radius exoplanet, measured with JWST NIRSpec's PRISM mode as part of the JWST Transiting Exoplanet Community Early Release Science Team program. We robustly detect multiple chemical species at high significance, including Na (19$σ$), H$_2$O (33$σ$), CO$_2$ (28$σ$), and CO (7$σ$). The non-detection of CH$_4$, combined with a strong CO$_2$ feature, favours atmospheric models with a super-solar atmospheric metallicity. An unanticipated absorption feature at 4$μ$m is best explained by SO$_2$ (2.7$σ$), which could be a tracer of atmospheric photochemistry. These observations demonstrate JWST's sensitivity to a rich diversity of exoplanet compositions and chemical processes.
