arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2011.03470astro-ph.EP
收藏

暖亚海王星HD3167c的透射光谱:分子吸收和可能的高金属度大气的证据

Transmission spectroscopy for the warm sub-Neptune HD3167c: evidence for molecular absorption and a possible high metallicity atmosphere

Thomas Mikal-Evans, Ian J. M. Crossfield, Bjorn Benneke, Laura Kreidberg, Julie Moses, Caroline V. Morley, Daniel Thorngren, Paul Molliere, Kevin K. Hardegree-U… 展开作者

Thomas Mikal-Evans, Ian J. M. Crossfield, Bjorn Benneke, Laura Kreidberg, Julie Moses, Caroline V. Morley, Daniel Thorngren, Paul Molliere, Kevin K. Hardegree-Ullman, John Brewer, Jessie L. Christiansen, David R. Ciardi, Diana Dragomir, Courtney Dressing, Jonathan J. Fortney, Varoujan Gorjian, Thomas P. Greene, Lea A. Hirsch, Andrew W. Howard, Steve B. Howell, Howard Isaacson, Molly R. Kosiarek, Jessica Krick, John H. Livingston, Joshua D. Lothringer, Farisa Y. Morales, Erik A. Petigura, Joshua E. Schlieder, Michael Werner

摘要:

我们提出了一个温暖的(500- 600 K)亚海王星HD 3167 c使用哈勃太空望远镜宽视场相机3红外光谱仪获得的透射光谱。我们结合这些数据,其中跨越1.125-1.643微米波长范围内,使用开普勒/K2(0.6-0.9微米)和斯皮策/IRAC(4-5微米)的宽带过境测量。我们发现了H2O,HCN,CO2和CH 4中至少一种吸收的证据(贝叶斯因子7.4; 2.5 σ显著性),尽管数据精度不允许我们明确区分这些分子。透射光谱排除了无云的氢为主的大气,金属丰度<100x solar at >5.8西格玛的信心。相比之下,假设金属丰度&gt; 700 x太阳能,则无云模型与数据吻合良好。然而,对于包括云的影响的检索分析,由于云顶压力的简并性,更广泛的金属丰度范围(包括太阳下)与数据一致。自洽的化学模式,占光化学和垂直混合的HD 3167 c的大气。这些模型的预测与我们的丰度限制基本一致,尽管这主要是由于后者的不确定性很大。内部结构模型表明,核心质量分数&gt; 40%,与岩石或水核心成分无关,与大气层金属丰度无关,最高可达1000倍太阳能。我们还报告了主恒星中15种元素的丰度测量结果,表明它具有非常接近太阳的成分。

英文摘要:

We present a transmission spectrum for the warm (500-600K) sub-Neptune HD3167c obtained using the Hubble Space Telescope Wide Field Camera 3 infrared spectrograph. We combine these data, which span the 1.125-1.643 micron wavelength range, with broadband transit measurements made using Kepler/K2 (0.6-0.9 micron) and Spitzer/IRAC (4-5 micron). We find evidence for absorption by at least one of H2O, HCN, CO2, and CH4 (Bayes factor 7.4; 2.5-sigma significance), although the data precision does not allow us to unambiguously discriminate between these molecules. The transmission spectrum rules out cloud-free hydrogen-dominated atmospheres with metallicities <100x solar at >5.8-sigma confidence. In contrast, good agreement with the data is obtained for cloud-free models assuming metallicities >700x solar. However, for retrieval analyses that include the effect of clouds, a much broader range of metallicities (including subsolar) is consistent with the data, due to the degeneracy with cloud-top pressure. Self-consistent chemistry models that account for photochemistry and vertical mixing are presented for the atmosphere of HD3167c. The predictions of these models are broadly consistent with our abundance constraints, although this is primarily due to the large uncertainties on the latter. Interior structure models suggest the core mass fraction is >40%, independent of a rock or water core composition, and independent of atmospheric envelope metallicity up to 1000x solar. We also report abundance measurements for fifteen elements in the host star, showing that it has a very nearly solar composition.

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。

↑