arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 1503.00180astro-ph.EPastro-ph.SR
收藏

探测活动恒星附近巨行星的最大熵方法

A maximum entropy approach to detect close-in giant planets around active stars

P. Petit, J. -F. Donati, E. Hébrard, J. Morin, C. P. Folsom, T. Böhm, I. Boisse, S. Borgniet, J. Bouvier, X. Delfosse, G. Hussain, S. V. Jeffers, S. C. Marsden, J. R. Barnes

摘要:

(简称arXiv)我们的目标是通过优化多普勒成像在径向速度测量中的使用,朝着更有效地探测活跃恒星周围的系外行星的方向发展。我们提出了一个简单的方法,同时提取亮度图和一组轨道参数,通过层析反演技术来自经典多普勒映射。根据最大熵原理,其基本思想是确定一套轨道参数,使所得到的多普勒图的信息量最小化。我们进行了一组的数值模拟进行初步评估的鲁棒性,我们的方法,使用实际的多普勒地图非常活跃的恒星HR 1099产生一个现实的合成数据集的各种设置的轨道参数的一个单一的行星在一个圆形轨道。使用模拟的时间序列的50线轮廓的影响的峰-峰活动抖动为2.5公里/秒,我们能够在大多数情况下恢复径向速度振幅,轨道相位和轨道周期的人造行星下降到径向速度半振幅的顺序的径向速度散射由于单独的光子噪声(约50米/秒,在我们的情况下)。一个值得注意的例外是,当行星轨道接近共同旋转时,在这种情况下,在重建的径向速度幅度中观察到显着的偏差,而轨道周期和相位仍然稳健地恢复。本方法构成了一个非常简单的方法来提取轨道参数从严重扭曲的线轮廓的活跃的恒星,当更经典的径向速度检测方法通常失败。它很容易适应大多数现有的多普勒成像代码,为系统搜索围绕年轻快速旋转恒星运行的近距离行星铺平了道路。

英文摘要:

(shortened for arXiv) We aim to progress towards more efficient exoplanet detection around active stars by optimizing the use of Doppler Imaging in radial velocity measurements. We propose a simple method to simultaneously extract a brightness map and a set of orbital parameters through a tomographic inversion technique derived from classical Doppler mapping. Based on the maximum entropy principle, the underlying idea is to determine the set of orbital parameters that minimizes the information content of the resulting Doppler map. We carry out a set of numerical simulations to perform a preliminary assessment of the robustness of our method, using an actual Doppler map of the very active star HR 1099 to produce a realistic synthetic data set for various sets of orbital parameters of a single planet in a circular orbit. Using a simulated time-series of 50 line profiles affected by a peak-to-peak activity jitter of 2.5 km/s, we are able in most cases to recover the radial velocity amplitude, orbital phase and orbital period of an artificial planet down to a radial velocity semi-amplitude of the order of the radial velocity scatter due to the photon noise alone (about 50 m/s in our case). One noticeable exception occurs when the planetary orbit is close to co-rotation, in which case significant biases are observed in the reconstructed radial velocity amplitude, while the orbital period and phase remain robustly recovered. The present method constitutes a very simple way to extract orbital parameters from heavily distorted line profiles of active stars, when more classical radial velocity detection methods generally fail. It is easily adaptable to most existing Doppler Imaging codes, paving the way towards a systematic search for close-in planets orbiting young, rapidly-rotating stars.

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。

↑