Defocused transmission spectroscopy: a potential detection of sodium in the atmosphere of WASP-12b
Defocused transmission spectroscopy: a potential detection of sodium in the atmosphere of WASP-12b
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DOI：
10.1093/mnras/stu2149
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发表时间：
2014-10
影响因子：
4.8
通讯作者：
J. Burton;J. Burton;C. Watson;P. Rodríguez-Gil;P. Rodríguez-Gil;I. Skillen;S. Littlefair;S. Dhillon;D. Pollacco
中科院分区：
文献类型：
--
作者：
J. Burton;J. Burton;C. Watson;P. Rodríguez-Gil;P. Rodríguez-Gil;I. Skillen;S. Littlefair;S. Dhillon;D. Pollacco
我们报告了一个试点研究的一种新的观测技术，散焦透射光谱，及其应用于研究系外行星大气层使用地面平台。与散焦测光类似，散焦透射光谱学比普通光谱学具有额外的优点，因为它减少了由于平场、点扩散函数变化、缝颚缺陷和与地面观测相关的其他影响而引起的系统误差。对于所研究的行星系统之一WASP-12 b，我们报告了在使用2 A波长掩模的过境期间对0.12 ± 0.03[+0.03] %的额外Na吸收的初步检测。考虑到在过境过程中发生的系统性变化，真实深度实际上可能更接近0.15%，这与HD 209458 b大气中报告的吸收水平（0.135 ± 0.017%; Snellen等人，2008年）相似。最后，我们概述的方法，将在未来的观察，根据我们的研究结果，从这个试点研究中改进的技术。
We report on a pilot study of a novel observing technique, defocused transmission spectroscopy, and its application to the study of exoplanet atmospheres using ground-based platforms. Similar to defocused photometry, defocused transmission spectroscopy has an added advantage over normal spectroscopy in that it reduces systematic errors due to flat-fielding, point spread function variations, slit-jaw imperfections and other effects associated with ground-based observations. For one of the planetary systems studied, WASP-12b, we report a tentative detection of additional Na absorption of 0.12 ± 0.03[+0.03] per cent during transit using a 2 A wavelength mask. After consideration of a systematic that occurs mid-transit, it is likely that the true depth is actually closer to 0.15 per cent. This is a similar level of absorption reported in the atmosphere of HD 209458b (0.135 ± 0.017 per cent; Snellen et al. 2008). Finally, we outline methods that will improve the technique during future observations, based on our findings from this pilot study.