Probing the extreme planetary atmosphere of WASP-12b
Probing the extreme planetary atmosphere of WASP-12b
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DOI：
10.1016/j.icarus.2013.04.003
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发表时间：
2012-05
期刊：
影响因子：
3.2
通讯作者：
M. Swain;P. Deroo;G. Tinetti;M. Hollis;M. Tessenyi;M. Line;H. Kawahara;Y. Fujii;A. Showman;S. Yurchenko
中科院分区：
文献类型：
--
作者：
M. Swain;P. Deroo;G. Tinetti;M. Hollis;M. Tessenyi;M. Line;H. Kawahara;Y. Fujii;A. Showman;S. Yurchenko
我们报告的近红外测量的终结者区域的透射光谱和昼侧发射光谱的系外行星WASP-12 b获得使用HST WFC 3仪器。日面亮温平均值约为2900 K，在1.46μm附近达到最高值3200 K。我们模拟了一系列大气情况的发射和透射光谱，并证实了Crossfield等人最近的发现（Crossfield，I.，Barman，T.，汉森，B，田中岛，Kodama，T. [2012年b]。arXiv：1210.4836C），没有证据表明WASP-12 b的大气中C/O>1。假设一个物理上合理的气氛中，我们发现的证据表明，一些分子的存在与数据是一致的，但这些不透明度来源的贝叶斯信息准则（BIC）的基础上列入的理由是边际。我们还发现近红外主食光变曲线与少量的扁长畸变一致。作为这些数据的校准工作的一部分，我们进行了详细的研究，仪器系统使用65轨道的WFC 3-IR格里姆斯观测。仪器系统学主要由探测器相关的影响，这取决于探测器读出模式显着变化。WASP-12的256×256子阵列观测使用简单的校准方法产生了在光子噪声限制的15%内的光谱测量。残留的系统性物质估计为70 ppm。
We report near-infrared measurements of the terminator region transmission spectrum and dayside emission spectrum of the exoplanet WASP-12b obtained using the HST WFC3 instrument. The disk-average dayside brightness temperature averages about 2900K, peaking to 3200K around 1.46μm. We modeled a range of atmospheric cases for both the emission and transmission spectrum and confirm the recent finding by Crossfield et al. (Crossfield, I., Barman, T., Hansen, B., Tanaka, I., Kodama, T. [2012b]. arXiv: 1210.4836C) that there is no evidence for C/O>1 in the atmosphere of WASP-12b. Assuming a physically plausible atmosphere, we find evidence that the presence of a number of molecules is consistent with the data, but the justification for inclusion of these opacity sources based on the Bayesian Information Criterion (BIC) is marginal. We also find the near-infrared primary eclipse light curve is consistent with small amounts of prolate distortion. As part of the calibration effort for these data, we conducted a detailed study of instrument systematics using 65 orbits of WFC3-IR grims observations. The instrument systematics are dominated by detector-related affects, which vary significantly depending on the detector readout mode. The 256×256 subarray observations of WASP-12 produced spectral measurements within 15% of the photon-noise limit using a simple calibration approach. Residual systematics are estimated to be ⩽70ppm.