We investigate the impact of photochemical hazes and disequilibrium gases on the thermal structure of hot Jupiters, using a detailed 1D radiative-convective model. We find that the inclusion of photochemical hazes results in major heating of the upper and cooling of the lower atmosphere. Sulphur containing species, such as SH, S2, and S3, provide significant opacity in the middle atmosphere and lead to local heating near 1 mbar, while OH, CH, NH, and CN radicals produced by the photochemistry affect the thermal structure near 1 $\mu$bar. Furthermore, we show that the modifications on the thermal structure from photochemical gases and hazes can have important ramifications for the interpretation of transit observations. Specifically, our study for the hazy HD 189733 b shows that the hotter upper atmosphere resulting from the inclusion of photochemical haze opacity imposes an expansion of the atmosphere, thus a steeper transit signature in the ultraviolet–visible part of the spectrum. In addition, the temperature changes in the photosphere also affect the secondary eclipse spectrum. For HD 209458 b, we find that a small haze opacity could be present in this atmosphere, at pressures below 1 mbar, which could be a result of both photochemical hazes and condensates. Our results motivate the inclusion of radiative feedback from photochemical hazes in general circulation models for a proper evaluation of atmospheric dynamics.

中文翻译：

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光化学霾和气体对系外行星大气热结构的影响

我们使用详细的一维辐射-对流模型研究了光化学霾和不平衡气体对热木星热结构的影响。我们发现光化学雾的包含导致上层大气的主要加热和低层大气的冷却。含硫物质，如 SH、S2 和 S3，在中层大气中提供显着的不透明度，并导致接近 1 mbar 的局部加热，而光化学产生的 OH、CH、NH 和 CN 自由基影响接近 1 $ 的热结构\亩$酒吧。此外，我们表明，光化学气体和雾霾对热结构的改变可能对解释凌日观测产生重要影响。具体来说，我们对朦胧的 HD 189733 b 的研究表明，由于包含光化学霾不透明度而导致的更热的上层大气会导致大气膨胀，因此在光谱的紫外-可见部分有更陡峭的凌日特征。此外，光球层的温度变化也会影响次食光谱。对于 HD 209458 b，我们发现在低于 1 mbar 的压力下，这种大气中可能存在小的雾度不透明度，这可能是光化学雾度和冷凝物的结果。我们的研究结果促使将来自光化学雾霾的辐射反馈纳入大气环流模型，以正确评估大气动力学。光球层的温度变化也会影响次食光谱。对于 HD 209458 b，我们发现在低于 1 mbar 的压力下，这种大气中可能存在小的雾度不透明度，这可能是光化学雾度和冷凝物的结果。我们的研究结果促使将来自光化学雾霾的辐射反馈纳入大气环流模型，以正确评估大气动力学。光球层的温度变化也会影响次食光谱。对于 HD 209458 b，我们发现在低于 1 mbar 的压力下，这种大气中可能存在小的雾度不透明度，这可能是光化学雾度和冷凝物的结果。我们的研究结果促使将来自光化学雾霾的辐射反馈纳入大气环流模型，以正确评估大气动力学。