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arXiv 1510.08062astro-ph.EP
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热彗星之友III:低质量恒星伴星的红外光谱搜索

Friends of Hot Jupiters III: An Infrared Spectroscopic Search for Low-Mass Stellar Companions

Danielle Piskorz, Heather A. Knutson, Henry Ngo, Philip S. Muirhead, Konstantin Batygin, Justin R. Crepp, Sasha Hinkley, Timothy D. Morton

摘要:

对附近恒星的调查表明,双星是常见的,但很少有人知道这些同伴可能对行星形成和演化的影响。热彗星之友项目使用三种互补的技术来寻找已知行星宿主恒星的伴星:径向速度监测,自适应光学成像和近红外光谱。在本文中,我们研究了高分辨率K波段红外光谱的50个恒星托管气体巨行星的短周期轨道。我们使用光谱拟合搜索混合线,由于我们的目标恒星的光谱中存在的冷恒星同伴,在那里我们是敏感的温度在3500-5000 K之间的同伴和投影分离小于100 AU在大多数系统。我们确定了8个系统的候选低质量的同伴,包括一个同伴,独立检测到我们的AO成像调查。对于具有径向速度加速度的系统,光谱检测不到排除了涉及高倾角轨道上的恒星伴星的情况。我们使用这些数据放置在小的投影分离的恒星二元分数的上限,并表明,观察到的人口的候选同伴是一致的场星,也与人口的宽分离同伴在我们以前的AO调查。我们没有发现任何证据表明,光谱恒星同伴优先位于偏心和/或错位轨道上的短周期气体巨行星系统。

英文摘要:

Surveys of nearby field stars indicate that stellar binaries are common, yet little is known about the effects that these companions may have on planet formation and evolution. The Friends of Hot Jupiters project uses three complementary techniques to search for stellar companions to known planet-hosting stars: radial velocity monitoring, adaptive optics imaging, and near-infrared spectroscopy. In this paper, we examine high-resolution K band infrared spectra of fifty stars hosting gas giant planets on short-period orbits. We use spectral fitting to search for blended lines due to the presence of cool stellar companions in the spectra of our target stars, where we are sensitive to companions with temperatures between 3500-5000 K and projected separations less than 100 AU in most systems. We identify eight systems with candidate low-mass companions, including one companion that was independently detected in our AO imaging survey. For systems with radial velocity accelerations, a spectroscopic non-detection rules out scenarios involving a stellar companion in a high inclination orbit. We use these data to place an upper limit on the stellar binary fraction at small projected separations, and show that the observed population of candidate companions is consistent with that of field stars and also with the population of wide-separation companions detected in our previous AO survey. We find no evidence that spectroscopic stellar companions are preferentially located in systems with short-period gas giant planets on eccentric and/or misaligned orbits.

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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