THE MASS–METALLICITY RELATION FOR GIANT PLANETS
THE MASS–METALLICITY RELATION FOR GIANT PLANETS
复制标题
巨行星的质量-金属丰度关系
DOI：
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
E. Lopez
中科院分区：
文献类型：
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作者：
D. Thorngren;J. Fortney;R. Murray;E. Lopez
近年来，系外行星的发现为研究巨行星的体成分提供了大量新的数据。在这里，我们确定了47颗凌日巨行星（20 MJ < M < 20 MJ），它们的恒星日射量足够低（F* < 2 × 108 erg s−1 cm−2，或近似Teff < 1000），不受热木星半径膨胀机制的影响。我们计算了一组新的热和结构演化模型，并使用这些模型与47个过境行星的性质（质量，半径，年龄）进行比较，以确定它们的重元素质量。行星重元素质量Mz和行星总质量之间存在着明显的相关性，近似为下式。这一发现与行星形成的核心吸积模型一致。我们还研究了恒星金属丰度[Fe/H]如何影响行星金属富集，并发现比以前报道的样本量较小的研究更弱的相关性。我们确认了行星金属富集相对于母星星Zplanet/Z星星和行星质量之间的强关系，但没有看到在Zplanet/Z星星与行星轨道性质或恒星质量的关系。许多行星的重元素质量都很大（>50 M），这意味着大量的重元素存在于氢/氦包层中，而不是核心中，因此富含金属的巨行星大气应该是规则。我们还讨论了一维盘中核心吸积行星形成的模型，并表明它与我们推导出的质量与Zplanet/Zstar之间的关系非常一致。
Exoplanet discoveries of recent years have provided a great deal of new data for studying the bulk compositions of giant planets. Here we identify 47 transiting giant planets (20 M⊕ < M < 20 MJ) whose stellar insolations are low enough (F* < 2 × 108 erg s−1 cm−2, or roughly Teff < 1000) that they are not affected by the hot-Jupiter radius inflation mechanism(s). We compute a set of new thermal and structural evolution models and use these models in comparison with properties of the 47 transiting planets (mass, radius, age) to determine their heavy element masses. A clear correlation emerges between the planetary heavy element mass Mz and the total planet mass, approximately of the form . This finding is consistent with the core-accretion model of planet formation. We also study how stellar metallicity [Fe/H] affects planetary metal-enrichment and find a weaker correlation than has previously been reported from studies with smaller sample sizes. We confirm a strong relationship between the planetary metal-enrichment relative to the parent star Zplanet/Zstar and the planetary mass, but see no relation in Zplanet/Zstar with planet orbital properties or stellar mass. The large heavy element masses of many planets (>50 M⊕) suggest significant amounts of heavy elements in H/He envelopes, rather than cores, such that metal-enriched giant planet atmospheres should be the rule. We also discuss a model of core-accretion planet formation in a one-dimensional disk and show that it agrees well with our derived relation between mass and Zplanet/Zstar.
影响因子：
3.2
作者：
Fletcher, L. N.;Orton, G. S.;Bjoraker, G. L.
通讯作者：
Bjoraker, G. L.