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arXiv 1902.07944astro-ph.EP
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在光学到近红外跃迁区中热到超热闪烁体的低辐射剂量

Low albedos of hot to ultra-hot Jupiters in the optical to near-infrared transition regime

M. Mallonn, J. Köhler, X. Alexoudi, C. von Essen, T. Granzer, K. Poppenhaeger, K. G. Strassmeier

摘要:

二次日食的深度包含了热木星的热发射光分量和反射光分量的信息。如果假设行星昼侧的大气是等温的,就有可能解开两者的纠缠。本文分析了热木星HAT-P-32 b在z'波段0.89 $μ$ m处的11条食光曲线。我们以最先进的精度,-0.01 +-0.10 ppt获得了日食深度的零点检测。我们证实了以前的研究表明,一个非倒置的大气模型是不同意的测量发射光谱的HAT-P-32 b。我们推导出反射光分量的上限,因此,对行星的几何轨道$A_g$。97.5%置信上限为$A_g$ < 0.2。这是HAT-P-32 b的第一个反轨道约束,也是任何系外行星的第一个z'波段反轨道值。它不利于大尺寸的硅酸盐凝析物对行星昼侧的影响。我们从已发表的日食测量结果中推断出z'波段的几何轨道极限,也适用于超热彗星WASP-12 b、WASP-19 b、WASP-103 b和WASP-121 b,使用相同的方法。这些值一致地指出,对于热到超热闪烁体,在光学到近红外过渡区中反射率低。

英文摘要:

The depth of a secondary eclipse contains information of both the thermally emitted light component of a hot Jupiter and the reflected light component. If the dayside atmosphere of the planet is assumed to be isothermal, it is possible to disentangle both. In this work, we analyze 11 eclipse light curves of the hot Jupiter HAT-P-32b obtained at 0.89 $μ$m in the z' band. We obtain a null detection for the eclipse depth with state-of-the-art precision, -0.01 +- 0.10 ppt. We confirm previous studies showing that a non-inverted atmosphere model is in disagreement to the measured emission spectrum of HAT-P-32b. We derive an upper limit on the reflected light component, and thus, on the planetary geometric albedo $A_g$. The 97.5%-confidence upper limit is $A_g$ < 0.2. This is the first albedo constraint for HAT-P-32b, and the first z' band albedo value for any exoplanet. It disfavors the influence of large-sized silicate condensates on the planetary day side. We inferred z' band geometric albedo limits from published eclipse measurements also for the ultra-hot Jupiters WASP-12b, WASP-19b, WASP-103b, and WASP-121b, applying the same method. These values consistently point to a low reflectivity in the optical to near-infrared transition regime for hot to ultra-hot Jupiters.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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