Photometric and structural parameters of newly discovered nuclear star clusters in Local Volume galaxies
Photometric and structural parameters of newly discovered nuclear star clusters in Local Volume galaxies
复制标题
局域体积星系中新发现的核星团的光度和结构参数
DOI：
10.1093/mnras/stad220
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发表时间：
2023
影响因子：
4.8
通讯作者：
Greene, Jenny E
中科院分区：
文献类型：
--
作者：
Hoyer, Nils;Neumayer, Nadine;Seth, Anil C;Georgiev, Iskren Y;Greene, Jenny E
本文利用哈勃空间望远镜高分辨率的矮星系成像数据对19个新发现的核星星团进行了参数化。大多数星团的质量都是恒星质量，在椭圆率、有效半径、恒星质量和表面密度方面可以与银河系球状星团相比较。这些星系团采用Sérsic轮廓建模，在有效半径处评估的表面亮度显示出与宿主星系恒星质量的紧密正相关性。我们的数据还表明，随着质量的增加，密度曲线的斜率增加，这可能表明在更大质量的宿主中，原位恒星形成的作用越来越大。我们评估了星系团和它们的宿主星系恒星质量之间的标度关系，以找到一个环境依赖性：对于场星系中的NSC，该关系的斜率是，对于室女座星系团核心中的矮星。将聚类的拟合限制在1σ区间内，与现场环境一致。环境的依赖性是由于最低质量的有核星系，我们推测，这是由于越来越多的祖球状星团合并成为一个NSC，或由于形成更大质量的球状星团在稠密的环境中，取决于初始球状星团质量函数。我们的结果清楚地证实了最近的结果，在矮星系中的NSC和球状星团之间存在着紧密的联系。
We use high-resolutionHubble Space Telescopeimaging data of dwarf galaxies in the Local Volume () to parameterize 19 newly discovered nuclear star clusters (NSCs). Most of the clusters have stellar masses ofand compare to Galactic globular clusters in terms of ellipticity, effective radius, stellar mass, and surface density. The clusters are modelled with a Sérsic profile and their surface brightness evaluated at the effective radius reveals a tight positive correlation to the host galaxy stellar mass. Our data also indicate an increase in slope of the density profiles with increasing mass, perhaps indicating an increasing role forin situstar formation in more massive hosts. We evaluate the scaling relation between the clusters and their host galaxy stellar mass to find an environmental dependence: for NSCs in field galaxies, the slope of the relation iswhereasfor dwarfs in the core of the Virgo cluster. Restricting the fit for the cluster toyields, in agreement with the field environment within the 1σ interval. The environmental dependence is due to the lowest-mass nucleated galaxies and we speculate that this is either due to an increased number of progenitor globular clusters merging to become an NSC, or due to the formation of more massive globular clusters in dense environments, depending on the initial globular cluster mass function. Our results clearly corroborate recent results in that there exists a tight connection between NSCs and globular clusters in dwarf galaxies.