Observations of galaxy isophotes, long-slit kinematics, and high-resolution photometry suggested a possible dichotomy between two distinct classes of elliptical galaxies. But these methods are expensive for large galaxy samples. Instead, integral field spectroscopy can efficiently recognize the shape, dynamics, and stellar population of complete samples of early-type galaxies (ETGs). These studies showed that the two main classes, the fast and slow rotators, can be separated using stellar kinematics. I show that there is a dichotomy in the dynamics of the two classes. The slow rotators are weakly triaxial and dominate above . Below Mcrit, the structure of fast rotators parallels that of spiral galaxies. There is a smooth sequence along which the age, the metal content, the enhancement in α-elements, and the weight of the stellar initial mass function all increase with the central mass density slope, or bulge mass fraction, while the molecular gas fraction correspondingly decreases. The properties of ETGs ...

中文翻译：

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从积分场光谱看早型星系的结构和运动学

对星系等光线、长狭缝运动学和高分辨率光度测量的观察表明，两种不同的椭圆星系可能存在二分法。但是这些方法对于大型星系样本来说是昂贵的。相反，积分场光谱可以有效地识别早型星系 (ETG) 完整样本的形状、动力学和恒星种群。这些研究表明，可以使用恒星运动学将快旋体和慢旋体这两个主要类别分开。我表明这两个类的动态存在二分法。慢速旋转体是弱三轴的，在上方占主导地位。在 Mcrit 之下，快速旋转器的结构与螺旋星系的结构相似。有一个平滑的序列，其中年龄、金属含量、α 元素的增强、并且恒星初始质量函数的权重都随着中心质量密度斜率或膨胀质量分数的增加而增加，而分子气体分数则相应地减少。ETG的特性...