论文标题
PAL 13:中度延伸的低密度光环及其积聚历史
Pal 13: its moderately extended low density halo and its accretion history
论文作者
论文摘要
我们根据深色能量摄像机的遗产调查(贴花)介绍结果DR8星体和光度数据集的球状群集PAL 13。由于其相对小的尺寸和质量,尚未就其周围的潮汐外结构存在一般共识。尽管一些先前的结果声称缺乏此类特征,但其他结果表明该群集处于潮汐剥离的影响下。从贴花G中,沿着颜色 - 磁性图中的簇主序列放置的恒星的r幅度 - 通过星际红登陆校正 - 我们构建了群集恒星密度图。所得的密度图显示了PAL约13左右的几乎平滑轮廓,是其雅各比半径的最新估计值的1.6倍,这是通过考虑其沿其轨道运动的变化而得出的。这种结果有利于恒星逃脱簇的存在,这是在球状簇中经常看到的这种现象,该现象越过了银河系盘的大量次数。特别是,该积聚的球状簇的轨道高偏心率和较大的倾斜角可能导致了相对较大的簇质量损失。
We present results on the basis of Dark Energy Camera Legacy Survey (DECaLS) DR8 astrometric and photometric data sets of the Milky Way globular cluster Pal 13. Because of its relative small size and mass, there has not been yet a general consensus about the existence of extra-tidal structures around it. While some previous results claim for the absence of such features, others have shown that the cluster is under the effects of tidal stripping. From DECaLS g,r magnitudes of stars placed along the cluster Main Sequence in the colour-magnitude diagram --previously corrected by interstellar reddening--, we built the cluster stellar density map. The resulting density map shows nearly smooth contours around Pal 13 out to 1.6 times the most recent estimate of its Jacobi radius, derived by taking into account its variation along its orbital motion. This outcome favours the presence of stars escaping the cluster, a phenomenon frequently seen in globular clusters that have crossed the Milky Way disc a comparable large number of times. Particularly, the orbital high eccentricity and large inclination angle of this accreted globular cluster could have been responsible for the relatively large amount of cluster mass lost.