论文标题
棕色矮人和凯克/nirspec的棕色矮人和极性巨型行星大气的h $ _3^+$的极限限制
Limits on the Auroral Generation of H$_3^+$ in Brown Dwarf and Extrasolar Giant Planet Atmospheres with Keck/NIRSPEC
论文作者
论文摘要
分子离子H $ _3^+$是Jovian行星的电离层和热结构的潜在强大示踪剂，但从未在太阳系以外的行星质量物体中检测到。模型预测，H $ _3^+$发射由EUV通量和太阳风驱动在热木星上，或者是在棕色矮人上强大的Aurorae驱动的，将在$ 10^2 $和$ 10^5 \ $ 10^5 \ times $中的强度在介于$ 10^5 \ times $之间。如果确实存在排放生产的最佳条件，则可以通过当前的地面工具或在不久的将来检测到排放。我们首次介绍了与keck/nirspec $ l^\ prime $高分辨率光谱的H $ _3^+$线排放。此外，我们调查的星星在半高轴上托管巨型行星的巨大行星接近$ 0.1-0.2 $ au，这表明这可能是最佳的行星目标。找不到候选人h $ _3^+$排放。我们对从棕色矮人发射H $ _3^+$的限制表明，在这些环境中，高$ _3^+$的极光产生可能不会从木星上的过程中线性扩展，这可能是由于通过促进极光电子来深度渗透。詹姆斯·韦伯（James Webb）太空望远镜（JWST）或将来的30米级望远镜可能可以使用棕色矮人的H $ _3^+$ $ $ $ $。
The molecular ion H$_3^+$ is a potentially powerful tracer of the ionospheres and thermal structures of Jovian planets, but has never been detected in a planetary mass object outside of the solar system. Models predict that H$_3^+$ emission driven by EUV flux and solar wind on hot Jupiters, or by powerful aurorae on brown dwarfs, will be between $10^2$ and $10^5\times$ more intense than that of Jupiter. If optimal conditions for the production of emission do exist, the emission may be detectable by current ground-based instruments or in the near future. We present the first search for H$_3^+$ line emission in brown dwarfs with Keck/NIRSPEC $L^\prime$ high-resolution spectroscopy. Additionally, we survey stars hosting giant planets at semi-major axes near $0.1-0.2$ au, which models suggest may be the best planetary targets. No candidate H$_3^+$ emission is found. The limits we place on the emission of H$_3^+$ from brown dwarfs indicates that auroral generation of H$_3^+$ in these environments likely does not linearly scale from the processes found on Jupiter, plausibly due to deeper atmospheric penetration by precipitating auroral electrons. Detection of H$_3^+$ emission in brown dwarfs may be possible with the James Webb Space Telescope (JWST), or future thirty-meter class telescopes.
