A study of bright southern slowly pulsating B stars* III. Mode identification for singly-periodic targets in spectroscopy
A study of bright southern slowly pulsating B stars* III. Mode identification for singly-periodic targets in spectroscopy
复制标题
对明亮的南方缓慢脉动 B 星的研究* III。
DOI：
10.1051/0004-6361:20042103
复制
发表时间：
2005
影响因子：
6.5
通讯作者：
C. Aerts
中科院分区：
文献类型：
--
作者：
P. Cat;M. Briquet;J. Daszyńska;M. Dupret;J. Ridder;R. Scuflaire;C. Aerts
我们给出了7颗明亮的南方缓慢脉动B星样本的模态识别结果，这些恒星在XX 413 nm Si II剖面上显示一个脉动频率。我们结合了(1)光度振幅法的结果；(2)矩量法；(3)在剖面上的振幅和相位变化，寻找最适合数据的模态的l和m值。这是第一次将这些技术的适用性测试到一个主序g模脉动器样本上。将矩量法与观测线剖面上的振幅和相位变化相结合，提高了低度g模脉动的光谱识别能力。使用高阶偶矩(v4>和（v6>）的矩法解决方案也可以有所帮助。对于HD 181558， HD 24587， HD 140873和HD 177863，光度和光谱结果是兼容的，并指向(I, m) =(1, +1)扇形模式。对于HD 215573、HD 53921和HD 92287，结果尚无定论。我们提出的模式识别方法也适用于剑鱼座y星。
We present the results of the mode identification for a sample of 7 bright southern slowly pulsating B stars showing onepulsation frequency in the XX 413 nm Si II profiles. We combined the results from (1) the method of photometric amplitudes; (2) the moment method; and (3) the amplitude and phase variation across the profile to search for the l and m values of the modes best fitting the data. It is the first time that the applicability of these techniques is tested to a sample of main-sequence g-mode pulsators. Combining the moment method with the amplitude and phase variations across the observed line profile gives an improvement in spectroscopic identification of low degree I g-mode pulsations. Using the variations of the higher order even moments (v4> and (v6> of the moment method solutions can also help. For HD 181558, HD 24587, HD 140873 and HD 177863, the photometric and spectroscopic results are compatible and point towards (I, m) = (1, +1) sectoral modes. For HD 215573, HD 53921 and HD 92287, the results are inconclusive. Our proposed methodology for mode identification is also applicable to y Doradus stars.