Binary Stars in Upper Scorpius
Binary Stars in Upper Scorpius
复制标题
天蝎座上部的双星
作者：
A. Tokovinin;C. Briceño
为了解决8 Myr老上天蝎座（USco）恒星形成区双星的统计问题，我们根据Luhman等人的名单，对614个质量大于0.4（光谱类型早于M3V）的星团成员进行了散斑干涉测量。 （2018）。我们解决了 187 对，其中 55 对是新发现。还使用已发布的数据和 Gaia DR2，生成了包含 250 个物理二进制文件的目录。我们仔细估计了每个目标的检测限，并研究了 0.″06 至 20″ (9–2800 au) 分离范围内的二进制统计数据，以及较大分离下的聚类。对于早期M型和太阳型恒星，在此分离范围内质量比q > 0.3的伴星频率分别为0.33±0.04和0.35±0.04，比类似质量的场星大1.62±0.22和1.39±0.18倍。多余的部分主要是由距离小于 100 个单位的对产生的。在 100 到 104 个天文单位的间隔处，间隔分布和伴星分数类似于场中的太阳型恒星。然而，与现场不同的是，与更小和更大的分离相比，我们在约 500 个天文单位的分离中看到等质量双星的相对不足。 q 的分布取决于间隔，在较小的间隔下优先选择较大的 q 和较大比例的 q > 0.95 的孪晶。 USco 的二元总体与该领域的二元总体在几个方面有所不同，这表明二元统计数据并不通用。
To address the statistics of binary stars in the 8 Myr old Upper Scorpius (USco) star formation region, we conducted a speckle interferometric survey of 614 association members more massive than 0.4 (spectral types earlier than M3V) based on the list of Luhman et al. (2018). We resolved 187 pairs, 55 of which are new discoveries. Also using the published data and the Gaia DR2, a catalog of 250 physical binaries was produced. We carefully estimated detection limits for each target and studied binary statistics in the separation range from 0.″06 to 20″ (9–2800 au), as well as clustering at larger separations. The frequency of companions with mass ratios q > 0.3 in this separation range is 0.33 ± 0.04 and 0.35 ± 0.04 for early M- and solar-type stars, respectively, larger by 1.62 ± 0.22 and 1.39 ± 0.18 times compared to field stars of similar masses. The excess is produced mostly by pairs closer than 100 au. At separations from 100 to 104 au, the separation distribution and companion fraction resemble those of solar-type stars in the field. However, unlike in the field, we see a relative deficit of equal-mass binaries at separations of ∼500 au, compared to smaller and larger separations. The distribution of q depends on the separation, with a preference of larger q and a larger fraction of twins with q > 0.95 at smaller separations. The binary population of USco differs from binaries in the field in several ways and suggests that binary statistics is not universal.
寻找任意分布中的双星分数
影响因子：
4.8
作者：
Akter S
通讯作者：
Akter S