Combing the brown dwarf desert with Gaia DR3
Combing the brown dwarf desert with Gaia DR3
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用 Gaia DR3 梳理褐矮星沙漠
DOI：
10.1093/mnras/stad3041
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发表时间：
2023
影响因子：
4.8
通讯作者：
Stevenson A
中科院分区：
文献类型：
--
作者：
Stevenson A
我们用P<；104d创建了一个包含214颗双星的最新棕矮星目录。这使我们能够检查BD沙漠的人口统计数据。我们搜索了GAI第三次数据发布(DR3)非单星(NSS)结果，得到了12个新的BD候选者的轨道倾角。其中三颗仍然是沙漠BDS，而九颗候选恒星被发现是低质量恒星。我们改进了以前研究过的三个BD候选者的径向速度(RV)解。在DR3BINARY_MASS数据库中还发现了19个周期小于∼1200d的BD质量块。我们确认了质量分布中的一个山谷，最小约为30-35 Mjup，并发现与较长的周期相比，<；100 d的周期仍然是人口稀少的。最新的BDS质量和偏心率分布仍然显示出高质量BD人群和低质量BD人群在统计学上的显著差异。这暗示了两种不同的母体分布，以及两种潜在的起源--要么类似于行星形成，要么类似于恒星。BDS的质量-金属丰度分布表明，核心吸积不是形成BDS的主要机制，因为它们不遵循巨型系外行星金属丰度的相同趋势。我们从34个月的数据中，根据目前可用的NSS解的探测阈值，在质量周期平面上识别出一个对角包络，边界为GaiaBDS。
We have created an up-to-date catalogue of 214 brown dwarfs (BDs) in binaries withP< 104d. This allows us to examine the population statistics of the BD desert. We searchedGaiathird data release (DR3) non-single star (NSS) results for orbital inclinations of BD candidates, deriving 12 new masses. Three remain as desert BDs whereas nine candidates are found to be low-mass stars. We improved the radial velocity (RV) solutions for three previously studied BD candidates. A further 19 BD masses with periods less than ∼1200 d were identified in the DR3binary_massesdata base. We confirm a valley in the mass distribution with a minimum around 30–35 Mjup, and find that periods <100 d are still underpopulated in comparison with longer periods. The updated mass and eccentricity distribution of BDs still shows a marginally statistically significant split into high- and low-mass BD populations. This hints at two different parent distributions, and two potential origins – either akin to planetary formation, or stellar. There are no low-eccentricity BDs at periods around 100 d. The mass–metallicity distribution of BDs indicates that core accretion is not the dominant formation mechanism for BDs as they do not follow the same trends that giant exoplanets do with metallicity. We identify a diagonal envelope bounding theGaiaBDs in the mass–period plane due to the detection thresholds of the currently available NSS solutions from 34 months of data.