Estimating stellar mean density through seismic inversions
Estimating stellar mean density through seismic inversions
复制标题
通过地震反演估计恒星平均密度
DOI：
10.1051/0004-6361/201118156
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发表时间：
2012
影响因子：
6.5
通讯作者：
Reese D
中科院分区：
文献类型：
--
作者：
Reese D
确定恒星的质量对于改进恒星演化理论和描述系外行星系统都至关重要。星震学为估算恒星平均密度提供了一条很有前途的途径。当结合精确的半径测定，如预期从盖亚，这产生准确的恒星质量。主要的困难是找到最好的方法来提取的平均密度的星星从一组观察到的frequency.AimsWe寻求建立一个新的方法来估计恒星的平均密度，它结合了简单的标度法，同时提供了一个反演technology.MethodsWe的准确性提供了一个框架，在其中构建和评估基于内核的线性反演，直接产生的平均密度的星星。然后，我们描述了三种不同的反演技术（SOLA和两个标度律），并将它们应用到太阳，几个测试案例和三颗恒星，α Cen B，HD 49933和HD 49385，其中两个观察CoRoT.ResultsThe SOLA（减法最佳本地化平均值）的方法和标度律的基础上，由Kjeldsen等人描述的表面校正技术。(2008，ApJ，683，L175）产生可比较的结果，其可以达到0.5%的精度，并且比缩放大的频率分离更好。其原因在于，来自前两种方法的平均核在质量上是相当的，并且比用大频率分离获得的平均核更好。它还表明，缩放大的频率分离是更敏感的近表面的影响，但受不正确的模式识别。因此，人们可以通过寻找一个可提供大频率分离的结果与其他两种方法之一的结果之间的最佳一致性的分配来识别脉动模式。非线性效应也进行了讨论，是混合模式的影响。特别是，我们表明，混合模式带来的平均密度估计，因为他们的适应性差的内核几乎没有改善。
ContextDetermining the mass of stars is crucial both for improving stellar evolution theory and for characterising exoplanetary systems. Asteroseismology offers a promising way for estimating the stellar mean density. When combined with accurate radii determinations, such as are expected fromGaia, this yields accurate stellar masses. The main difficulty is finding the best way to extract the mean density of a star from a set of observed frequencies.AimsWe seek to establish a new method for estimating the stellar mean density, which combines the simplicity of a scaling law while providing the accuracy of an inversion technique.MethodsWe provide a framework in which to construct and evaluate kernel-based linear inversions that directly yield the mean density of a star. We then describe three different inversion techniques (SOLA and two scaling laws) and apply them to the Sun, several test cases and three stars,αCen B, HD 49933 and HD 49385, two of which are observed by CoRoT.ResultsThe SOLA (subtractive optimally localised averages) approach and the scaling law based on the surface correcting technique described by Kjeldsen et al. (2008, ApJ, 683, L175) yield comparable results that can reach an accuracy of 0.5% and are better than scaling the large frequency separation. The reason for this is that the averaging kernels from the two first methods are comparable in quality and are better than what is obtained with the large frequency separation. It is also shown that scaling the large frequency separation is more sensitive to near-surface effects, but is much less affected by an incorrect mode identification. As a result, one can identify pulsation modes by looking for anℓandnassignment which provides the best agreement between the results from the large frequency separation and those from one of the two other methods. Non-linear effects are also discussed, as is the effects of mixed modes. In particular, we show that mixed modes bring little improvement to the mean density estimates because of their poorly adapted kernels.
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影响因子：
6.5
作者：
P. Eggenberger;C. Charbonnel;S. Talon;G. Meynet;A. Maeder;Fabien Carrier;G. Bourban
通讯作者：
P. Eggenberger;C. Charbonnel;S. Talon;G. Meynet;A. Maeder;Fabien Carrier;G. Bourban
CoRoT-2 系统分析：一颗年轻的斑点恒星及其膨胀的巨行星
DOI：
10.1051/0004-6361/201015051
发表时间：
2010
期刊：
arXiv: Solar and Stellar Astrophysics
影响因子：
--
作者：
T. Guillot;M. Havel
通讯作者：
M. Havel
影响因子：
2.8
作者：
D. Gough;M. J. Thompson
通讯作者：
M. J. Thompson
DOI：
10.1046/j.1365-8711.1999.02785.x
发表时间：
1999-05
影响因子：
4.8
作者：
M. Rabello-Soares;S. Basu;J. Christensen-Dalsgaard
通讯作者：
M. Rabello-Soares;S. Basu;J. Christensen-Dalsgaard
高尔夫实验模式的初步结果
影响因子：
2.8
作者：
M. Lazrek;F. Baudin;L. Bertello;P. Boumier;J. Charra;D. Fierry;E. Fossat;A. Gabriel;Rafael A. García;B. Gelly;C. Gouiffès;G. Grec;P. Pallé;F. P. Hernández;C. Régulo;C. Renaud;J. Robillot;T. R. Cortés;S. Turck;R. Ulrich
通讯作者：
R. Ulrich