The VLT-FLAMES Tarantula Survey XXVII. Physical parameters of B-type main-sequence binary systems in the Tarantula nebula
The VLT-FLAMES Tarantula Survey XXVII. Physical parameters of B-type main-sequence binary systems in the Tarantula nebula
复制标题
DOI：
10.1051/0004-6361/201629982
复制
发表时间：
2017-04
期刊：
影响因子：
--
通讯作者：
C. J. Evans;N. Bastian;Y. Beletsky;I. Brott;M. Cantiello;Jeremy Simon Clark;P. Crowther;A. de Koter;S. D. de Mink;P. Dufton;P. Dunstall;M. Gieles;G. Gräfener;V. Hénault-Brunet;A. Herrero;I. D. Howarth;N. Langer;D. Lennon;J. M. Apellániz;N. Marková;F. Najarro;J. Puls;H. Saña;S. Simón-Díaz;S. Smartt;V. Stroud;W. D. Taylor;C. Trundle;J. VAN LOON;J. Vink;N. R. Walborn
中科院分区：
文献类型：
--
作者：
C. J. Evans;N. Bastian;Y. Beletsky;I. Brott;M. Cantiello;Jeremy Simon Clark;P. Crowther;A. de Koter;S. D. de Mink;P. Dufton;P. Dunstall;M. Gieles;G. Gräfener;V. Hénault-Brunet;A. Herrero;I. D. Howarth;N. Langer;D. Lennon;J. M. Apellániz;N. Marková;F. Najarro;J. Puls;H. Saña;S. Simón-Díaz;S. Smartt;V. Stroud;W. D. Taylor;C. Trundle;J. VAN LOON;J. Vink;N. R. Walborn
对VLT-火焰狼蛛巡天（VFTS）中的B型多星系（不包括超巨星主星系）进行了光谱分析。投影的旋转速度，$v$sin$i$，为原色已估计使用傅立叶变换技术，并确认通过拟合旋转加宽的配置文件。一个子集的33个系统与$v$sin$i$$\leq $80公里/秒已分析使用TLUSTY网格的模型大气，以估计恒星参数和表面丰度的原色。还考虑了来自看不见的次级的潜在通量贡献的影响。对于20个目标，有可能可靠地估计它们的有效温度（T$_{eff}$），但对于其他13个物体，只能提供20，000 T $_{eff}$26，000 K的约束-因此，为这些目标估计的其他参数将不太可靠。与演化模型进行了比较，结果与剑鱼座30的成员关系基本一致，并讨论了3SB 2系统的次级性质。与从VFTS获得的速度为80 km/s的单星样本进行比较，并使用相同的技术进行分析，这意味着两个样本的大气参数和氮丰度是相似的。然而，联星样本可能缺乏具有显著氮增强的主星，这与它们具有低旋转速度和有效地演化为没有显著旋转混合的单星相一致。这一结果，这实际上可能是本文中提出的探路者调查的局限性的后果，应被视为一个动机，光谱丰度分析的大样本的双星，高质量的观测数据。
A spectroscopic analysis has been undertaken for the B-type multiple systems (excluding those with supergiant primaries) in the VLT-FLAMES Tarantula Survey (VFTS). Projected rotational velocities, $v$sin$i$, for the primaries have been estimated using a Fourier Transform technique and confirmed by fitting rotationally broadened profiles. A subset of 33 systems with $v$sin$i$$\leq$ 80 km/s have been analysed using a TLUSTY grid of model atmospheres to estimate stellar parameters and surface abundances for the primaries. The effects of a potential flux contribution from an unseen secondary have also been considered. For 20 targets it was possible to reliably estimate their effective temperatures (T$_{eff}$) but for the other 13 objects it was only possible to provide a constraint of 20,000$\leq$T$_{eff}$$\leq$26,000 K -- the other parameters estimated for these targets will be consequently less reliable. The estimated stellar properties are compared with evolutionary models and are generally consistent with their membership of 30 Doradus, while the nature of the secondaries of 3 SB2 system is discussed. A comparison with a sample of single stars with $v$sin$i$$\leq$ 80 km/s obtained from the VFTS and analysed with the same techniques implies that the atmospheric parameters and nitrogen abundances of the two samples are similar. However, the binary sample may have a lack of primaries with significant nitrogen enhancements, which would be consistent with them having low rotational velocities and having effectively evolved as single stars without significant rotational mixing. This result, which may be actually a consequence of the limitations of the pathfinder investigation presented in this paper, should be considered as a motivation for spectroscopic abundance analysis of large samples of binary stars, with high quality observational data.