Extremely Irradiated Hot Jupiters: Non-oxide Inversions, H− Opacity, and Thermal Dissociation of Molecules
Extremely Irradiated Hot Jupiters: Non-oxide Inversions, H− Opacity, and Thermal Dissociation of Molecules
复制标题
极度辐照的热木星：非氧化物反转、H− 不透明度和分子的热解离
DOI：
10.3847/1538-4357/aadd9e
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
T. Koskinen
中科院分区：
文献类型：
--
作者：
J. Lothringer;T. Barman;T. Koskinen
受到极度辐射的热木星，以及白天温度超过 2000 K 的系外行星，扩展了我们对行星大气和用于解释观测的模型的理解。虽然这些天体在其他意义上都是行星，但它们的大气层在低压下达到的温度只能与恒星大气层相媲美。为了理解我们对这些物体性质的先验理论预期，我们使用 PHOENIX 模型大气代码自洽地模拟了许多极端炎热的木星场景。 PHOENIX 在从冷棕矮星到膨胀超新星壳的天体上进行了充分测试，其从紫外线到远红外的广泛不透明数据库使 PHOENIX 非常适合了解极度辐射的热木星。我们发现温度 >2500 K 的热木星和温度较低的木星之间存在一些根本差异。首先，Fe和Mg等原子金属、SiO和金属氢化物等分子以及H−等连续不透明源的吸收，所有这些与早期型主星的短波长输出相结合，导致强烈的热反转，而不需要TiO或VO。其次，包括 H2O、TiO 和 VO 在内的许多分子物种在凌日和日食观测探测到的压力下会热解离，这可能会使假设垂直丰度均匀的检索算法产生偏差。我们讨论了这些物体的其他有趣特性，以及观察和表征这一独特天体物理物体的未来前景和预测，包括已知最热木星行星 KELT-9b 的第一个自洽模型。
Extremely irradiated hot Jupiters, exoplanets reaching dayside temperatures >2000 K, stretch our understanding of planetary atmospheres and the models we use to interpret observations. While these objects are planets in every other sense, their atmospheres reach temperatures at low pressures comparable only to stellar atmospheres. In order to understand our a priori theoretical expectations for the nature of these objects, we self-consistently model a number of extreme hot Jupiter scenarios with the PHOENIX model atmosphere code. PHOENIX is well-tested on objects from cool brown dwarfs to expanding supernovae shells, and its expansive opacity database from the UV to far-IR make PHOENIX well-suited to understanding extremely irradiated hot Jupiters. We find several fundamental differences between hot Jupiters at temperatures >2500 K and their cooler counterparts. First, absorption by atomic metals like Fe and Mg, molecules including SiO and metal hydrides, and continuous opacity sources like H−, all combined with the short-wavelength output of early-type host stars, result in strong thermal inversions, without the need for TiO or VO. Second, many molecular species, including H2O, TiO, and VO are thermally dissociated at pressures probed by transit and eclipse observations, potentially biasing retrieval algorithms that assume uniform vertical abundances. We discuss other interesting properties of these objects, as well as future prospects and predictions for observing and characterizing this unique class of astrophysical object, including the first self-consistent model of the hottest known Jovian planet, KELT-9b.
影响因子：
4.8
作者：
S. Casewell;I. Braker;S. Parsons;J. Hermes;M. Burleigh;C. Belardi;A. Chaushev;N. Finch;M. Roy;S. Littlefair;M. Goad;E. Dennihy
通讯作者：
S. Casewell;I. Braker;S. Parsons;J. Hermes;M. Burleigh;C. Belardi;A. Chaushev;N. Finch;M. Roy;S. Littlefair;M. Goad;E. Dennihy
影响因子：
4.8
作者：
R. MacDonald;N. Madhusudhan
通讯作者：
R. MacDonald;N. Madhusudhan
DOI：
10.1051/0004-6361/201731129
发表时间：
2017-10
期刊：
arXiv: Earth and Planetary Astrophysics
影响因子：
--
作者：
J. Chadney;J. Chadney;T. Koskinen;M. Galand;Yvonne C. Unruh;J. Sanz-Forcada
通讯作者：
J. Chadney;J. Chadney;T. Koskinen;M. Galand;Yvonne C. Unruh;J. Sanz-Forcada