Solar-like oscillations in HD 181420: data analysis of 156 days of CoRoT data
Solar-like oscillations in HD 181420: data analysis of 156 days of CoRoT data
复制标题
HD 181420中的类太阳振荡：156天CoRoT数据的数据分析
DOI：
10.1051/0004-6361/200911937
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发表时间：
2009
影响因子：
6.5
通讯作者：
Barban C
中科院分区：
文献类型：
--
作者：
Barban C
类太阳振荡特性的估计，如它们的频率、振幅和寿命，具有挑战性，因为它们的振幅很低，并且将受益于长时间不间断的观测运行。太空望远镜CoRoT使我们能够在长时间和准连续的时间内获得高性能的光度数据。它的主要目标是那些我们预计会有类似太阳振荡的恒星。AimsHD 181420是一颗F2主序星，在其第一个长达156天的长期运行中被CoRoT观测到。有了这组前所未有的高质量数据，我们的目标是推导出可用于探测恒星内部的p模参数。方法采用经典傅里叶方法对hd181420上获得的CoRoT数据进行分析，寻找p模式特征。然后使用洛伦兹模型对功率谱进行全局拟合，得到p模参数，这在太阳的情况下被广泛使用。结果从p模频率可以估计出大间距的平均值为75。p模振幅略小于4ppm，在p模的最大值处线宽约为8。倾角估计在。较大的模态线宽和观测到的模态间距给模态识别和旋转分裂估计带来了困难。我们探讨了两种识别模式的场景。
ContextThe estimate of solar-like oscillation properties, such as their frequencies, amplitudes and lifetimes, is challenging because of their low amplitudes and will benefit from long and uninterrupted observing runs. The space telescope CoRoT allows us to obtain high-performance photometric data over a long and quasi continuous period. Among its main targets are stars for which we expect solar-like oscillations.AimsHD 181420, an F2 main sequence star, has been observed by CoRoT during its first long run covering about 156 days. With this unprecedently high-quality set of data, our aim is to derive the p-mode parameters that can be used to probe the stellar interior.MethodsThe CoRoT data obtained on HD 181420 is analysed using a classical Fourier approach for the search for the p mode signature. The p-mode parameters are then derived using global fitting of the power spectrum by a Lorentzian model, as used widely in the solar case.ResultsFrom the p-mode frequencies, the mean value of the large spacing is estimated to be 75 . The p-mode amplitudes are slightly less than 4 ppm with a line width of about 8 at the maximum of the p modes. The inclination angle is estimated to be around . The large mode line-width combined with the observed mode spacing make it difficult to identify the modes and to estimate the rotational splitting. We explore two scenarios for the identification of the modes.