论文标题
LH91中的预序列星
Pre-main Sequence stars in LH91
论文作者
论文摘要
我们研究了大麦芽云中LH 91关联中序列序列低质量恒星的增生性能。使用使用Hubble太空望远镜获得的光学多播放光度法，我们确定75个候选者，显示H $α$多余的发射，高于3 $σ$水平，其等效宽度$ ew_ {hα} $ $ \ ge ge $10Å。我们估计了前序列序列候选物的物理参数（有效温度，亮度，年龄，质量，积聚亮度和质量吸积率）。年龄分布表明，星形构造的范围从少数MYR到$ \ sim $ 60 MYR，差距在$ \ sim $ 5 Myr和10 Myr之间。 PMS候选者的质量从0.2 $ m _ {\ odot} $，对于冷却器对象到1.0 $ m _ {\ odot} $，中位数为$ \ sim $ 0.80 $ m _ {\ odot} $。我们75 pms星星的积聚发光度的中值价值约为0.12 $ l _ {\ odot} $，质量吸积率的中位价值约为4.8 $ \ times $ 10^{ - 9} $ 10^{ - 9} $ $ m _ {\ odot} yr^yr^yr^yr^for sim $ sim $ sim $ \ sim $ \ sim $ \。 $ 10^{ - 8} $ $ m _ {\ odot} yr^{ - 1} $），较旧候选人的值较低（$ \ sim $ 4.7 $ \ times $ $ $ $ $ 10^{ - 9} $ $ m _ {\ odot} yr^{ - 1} $）。我们将结果与LH 95的发现进行了比较，LH 95是LH 91的较近区域，该区域为PMS候选物的增值特性提供了比较。一个有趣的定性结果是，LH 91似乎处于更具进化的阶段。此外，我们发现PMS候选者是同质分布的，没有任何巨大恒星周围的团块的证据。
We study the accretion properties of pre-main sequence low-mass stars in the LH 91 association within the Large Magellanic Clouds. Using optical multiband photometry obtained with the Hubble Space Telescope, we identify 75 candidates showing H$α$ excess emission above the 3$σ$ level with equivalent width $EW_{Hα}$ $\ge$ 10 Å. We estimate the physical parameters (effective temperature, luminosity, age, mass, accretion luminosity and mass accretion rate) of the pre-main sequence stellar candidates. The age distribution suggests a star formation ranging from few Myr up to $\sim$ 60 Myr with a gap between $\sim$ 5 Myr and 10 Myr. The masses of the PMS candidates span from 0.2 $M_{\odot}$ for the cooler objects to 1.0 $M_{\odot}$ with a median of $\sim$ 0.80 $M_{\odot}$. The median value of the accretion luminosity of our 75 PMS stars is about 0.12 $L_{\odot}$, the median value of the mass accretion rate is about 4.8 $\times$ $10^{-9}$ $M_{\odot} yr^{-1}$ with higher values for the younger population ($\sim$ 1.2 $\times$ $10^{-8}$ $M_{\odot} yr^{-1}$), and lower values for the older candidates ($\sim$ 4.7 $\times$ $10^{-9}$ $M_{\odot} yr^{-1}$). We compare our results with the findings on LH 95, the closer region to LH 91 for which accretion properties of PMS candidates were derived. An interesting qualitative outcome is that LH 91 seems to be in a more evolved stage. Moreover, we find that the PMS candidates are distributed homogeneously, without any evidence of clumps around more massive stars.
