Mass ratios of the components in T Tauri binary systems and implications for multiple star formation
Mass ratios of the components in T Tauri binary systems and implications for multiple star formation
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金牛座 T 双星系统中各组分的质量比及其对多星形成的影响
DOI：
10.1051/0004-6361:20011034
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发表时间：
2001
期刊：
影响因子：
--
通讯作者：
R. Kohler
中科院分区：
文献类型：
--
作者：
J. Woitas;C. Leinert;R. Kohler
本文用近红外散斑干涉法对58个年轻双星系统的组分进行了分辨JHK光度测量。从这些测量，结合其他数据从文献中，我们得出的质量，特别是质量比的组件。我们使用J星等作为恒星光度的指标，并将系统的光谱类型分配给主星。假设一个双星中的组分是同时代的，那么我们就可以将双星也放入HRD中，并通过与不同的理论上的前主序演化轨迹进行比较，推导出两个组分的质量和质量比。当M（2）/M（1）> 0.2时，质量比的分布相对平坦，但取决于假设的演化轨迹。质量比与初级质量或组分分离度无关。这些发现符合这样的假设，即对于T星协中的大多数多系统，其组成部分的质量主要取决于形成过程中的碎裂，而不是随后的吸积过程。在被探测到的同伴中，只有极少数新发现的异常红色物体。这一发现表明，与附近的主序星相比，金牛座-御夫座星协中观测到的双星过多应该是真实的，而不是与红外观测有关的观测偏差的结果。
Using near-infrared speckle interferometry we have obtained resolved JHK-photometry for the components of 58 young binary systems. From these measurements, combined with other data taken from literature, we derive masses and particularly mass ratios of the components. We use the J-magnitude as an indicator for the stellar luminosity and assign the optical spectral type of the system to the primary. On the assumption that the components within a binary are coeval we can then place also the secondaries into the HRD and derive masses and mass ratios for both components by comparison with different sets of current theoretical pre-main sequence evolutionary tracks. The resulting distribution of mass ratios is comparatively flat for M(2)/M(1) > 0.2, but depends on assumed evolutionary tracks. The mass ratio is neither correlated with the primary's mass or the components' separation. These findings are in line with the assumption that for most multiple systems in T associations the components' masses are principally determined by fragmentation during formation and not by the following accretion processes. Only very few unusually red objects were newly found among the detected companions. This finding shows that the observed overabundance of binaries in the Taurus-Auriga association compared to nearby main sequence stars should be real and not the outcome of observational biases related to infrared observing.
影响因子：
3.2
作者：
V. Mannings;A. Boss;S. Russell
通讯作者：
V. Mannings;A. Boss;S. Russell