论文标题
遗物星系的球状簇系统
Globular Cluster Systems of Relic Galaxies
论文作者
论文摘要
我们分析了15个大规模紧凑的早期类型星系（ETG）样品的球状簇（GC）系统，其中13个已经被鉴定为良好的遗物星系候选者，这些候选者是基于其紧凑的形态，旧的恒星种群和恒星动力学。这些遗物星系候选人可能是附近的高红移红块星系的同行。使用F814W（〜I）和F160W（〜H）数据来自WFC3 CAMARA上的Hubble空间望远镜，我们确定GC系统的总数，光度函数，特定频率，颜色和空间分布。我们发现比可比质量的ETG较低的特异性频率（SN <2.5，中位数为Sn = 1）。这与快速，早期耗散形成的情况一致，低质量，高SN卫星的积聚水平相对较低。 GC半数字半径是紧凑的，但遵循正常ETG中发现的关系。我们确定了宿主星系的特定角动量（lambda_r）与其GC系统的（I-H）颜色分布宽度之间的反相关。假设Lambda_r提供了大规模ETG中耗散程度的度量，我们建议（I-H）颜色分布宽度可以用作这些系统中增生历史复杂性程度的代理。
We analyse the globular cluster (GC) systems of a sample of 15 massive, compact early-type galaxies (ETGs), 13 of which have already been identified as good relic galaxy candidates on the basis of their compact morphologies, old stellar populations and stellar kinematics. These relic galaxy candidates are likely the nearby counterparts of high redshift red nugget galaxies. Using F814W (~I) and F160W (~H) data from the WFC3 camara onboard the Hubble Space Telescope we determine the total number, luminosity function, specific frequency, colour and spatial distribution of the GC systems. We find lower specific frequencies (SN<2.5 with a median of SN=1) than ETGs of comparable mass. This is consistent with a scenario of rapid, early dissipative formation, with relatively low levels of accretion of low-mass, high-SN satellites. The GC half-number radii are compact, but follow the relations found in normal ETGs. We identify an anticorrelation between the specific angular momentum (lambda_R) of the host galaxy and the (I-H) colour distribution width of their GC systems. Assuming that lambda_R provides a measure of the degree of dissipation in massive ETGs, we suggest that the (I-H) colour distribution width can be used as a proxy for the degree of complexity of the accretion histories in these systems.
