Exoplanet secondary atmosphere loss and revival
Exoplanet secondary atmosphere loss and revival
复制标题
系外行星次生大气的丧失与复兴
DOI：
--
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发表时间：
2020
影响因子：
11.1
通讯作者：
M. Barnett
中科院分区：
文献类型：
--
作者：
E. Kite;M. Barnett
地球和金星都有大气层，但水星没有。已知的系外行星数以千计，但我们对岩石系外行星的大气层几乎一无所知。许多岩石系外行星是由次海王星到超级地球的转换过程形成的，在此过程中，行星失去了大部分富含H2的（主要）大气，体积减少了2倍以上。这样一个富含气体的青春期是否会增加或减少超级地球随后表现出贫氢（次级）大气的可能性？我们发现，从岩浆海洋中析出的次级大气不太可能被超级地球保留下来，但火山放气有可能恢复超级地球大气。对于M型矮行星系统来说，拥有接近星星大气层的超级地球可能是由丰富的挥发物形成的。在通往另一个地球的道路上，下一步是在岩石系外行星上找到与地球和金星相似的大气层--高分子量（二级）大气层。许多岩石系外行星出生时都有厚厚的（>10 kbar）以H2为主的大气层，但随后会失去H2;这个过程在太阳系中没有已知的类似过程。我们研究的后果，早期损失的厚H2大气随后发生的高分子量的大气，使用一个简单的大气演化模型（包括大气损失空间，岩浆海洋结晶，火山放气）。我们还计算了没有H2的岩石世界的大气生存。我们的研究结果意味着，大多数岩石系外行星的轨道更接近它们的星星，而不是由厚厚的H2主导的大气层形成的可居住区，今天缺乏高分子量的大气层。在早期的岩浆海洋结晶过程中，高分子量物质通常不会形成长寿的高分子量大气;相反，它们与H2一起消失在太空中。这种早期的挥发性消耗也使得后来的火山释气更难恢复大气层。然而，大气层应该会持续存在于挥发物丰富的世界（例如，水世界）。我们的研究结果意味着，为了在绕M星运行的温暖系外行星上找到高分子量的大气，我们应该瞄准那些形成H2贫乏，半径非常大，或者绕不太活跃的恒星运行的世界。
Significance Earth and Venus have significant atmospheres, but Mercury does not. Thousands of exoplanets are known, but we know almost nothing about rocky exoplanet atmospheres. Many rocky exoplanets were formed by a sub-Neptune-to-super-Earth conversion process during which planets lose most of their H2-rich (primary) atmospheres and are reduced in volume by a factor of >2. Does such a gas-rich adolescence increase or decrease the likelihood that super-Earths will subsequently exhibit a H2-poor (secondary) atmosphere? We show that secondary atmospheres exsolved from the magma ocean are unlikely to be retained by super-Earths, but it is possible for volcanic outgassing to revive super-Earth atmospheres. For M-dwarf planetary systems, super-Earths that have atmospheres close to the star likely were formed with abundant volatiles. The next step on the path toward another Earth is to find atmospheres similar to those of Earth and Venus—high–molecular-weight (secondary) atmospheres—on rocky exoplanets. Many rocky exoplanets are born with thick (>10 kbar) H2-dominated atmospheres but subsequently lose their H2; this process has no known Solar System analog. We study the consequences of early loss of a thick H2 atmosphere for subsequent occurrence of a high–molecular-weight atmosphere using a simple model of atmosphere evolution (including atmosphere loss to space, magma ocean crystallization, and volcanic outgassing). We also calculate atmosphere survival for rocky worlds that start with no H2. Our results imply that most rocky exoplanets orbiting closer to their star than the habitable zone that were formed with thick H2-dominated atmospheres lack high–molecular-weight atmospheres today. During early magma ocean crystallization, high–molecular-weight species usually do not form long-lived high–molecular-weight atmospheres; instead, they are lost to space alongside H2. This early volatile depletion also makes it more difficult for later volcanic outgassing to revive the atmosphere. However, atmospheres should persist on worlds that start with abundant volatiles (for example, water worlds). Our results imply that in order to find high–molecular-weight atmospheres on warm exoplanets orbiting M-stars, we should target worlds that formed H2-poor, that have anomalously large radii, or that orbit less active stars.
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影响因子：
5.3
作者：
Andrault, Denis;Bolfan-Casanova, Nathalie;Mezouar, Mohamed
通讯作者：
Mezouar, Mohamed
影响因子：
3.9
作者：
Miyazaki, Yoshinori;Korenaga, Jun
通讯作者：
Korenaga, Jun
具有耦合气候-内部模型的早期地球蒸汽大气的演化和光谱响应
DOI：
10.3847/1538-4357/ab0d85
发表时间：
2019
期刊：
The Astrophysical Journal
影响因子：
--
作者：
Katyal;Nikolaou;Godolt;Grenfell;Schreier
通讯作者：
Schreier
哪些因素影响陆地岩浆海的持续时间和释气？
DOI：
10.3847/1538-4357/ab08ed
发表时间：
2019
期刊：
The Astrophysical Journal
影响因子：
--
作者：
Nikolaou;Katyal;Godolt;Grenfell
通讯作者：
Grenfell
DOI：
10.1088/1538-3873/aadf6f
发表时间：
2018-05
影响因子：
3.5
作者：
E. Kempton;J. Bean;D. Louie;D. Deming;D. Koll;M. Mansfield;J. Christiansen;M. López-Morales;M. Swain;R. Zellem;S. Ballard;T. Barclay;J. Barstow;N. Batalha;T. Beatty;Z. Berta-Thompson;J. Birkby;L. Buchhave;D. Charbonneau;N. Cowan;I. Crossfield;Miguel de Val-Borro;R. Doyon;D. Dragomir;E. Gaidos;K. Heng;R. Hu;S. Kane;L. Kreidberg;M. Mallonn;C. Morley;N. Narita;V. Nascimbeni;E. Pallé;E. Quintana;E. Rauscher;S. Seager;E. Shkolnik;D. Sing;A. Sozzetti;K. Stassun;J. Valenti;C. V. Essen
通讯作者：
E. Kempton;J. Bean;D. Louie;D. Deming;D. Koll;M. Mansfield;J. Christiansen;M. López-Morales;M. Swain;R. Zellem;S. Ballard;T. Barclay;J. Barstow;N. Batalha;T. Beatty;Z. Berta-Thompson;J. Birkby;L. Buchhave;D. Charbonneau;N. Cowan;I. Crossfield;Miguel de Val-Borro;R. Doyon;D. Dragomir;E. Gaidos;K. Heng;R. Hu;S. Kane;L. Kreidberg;M. Mallonn;C. Morley;N. Narita;V. Nascimbeni;E. Pallé;E. Quintana;E. Rauscher;S. Seager;E. Shkolnik;D. Sing;A. Sozzetti;K. Stassun;J. Valenti;C. V. Essen