We present spatially resolved two-dimensional maps and radial trends of the stellar populations and kinematics for a sample of six compact elliptical galaxies (cE) using spectroscopy from the Keck Cosmic Web Imager (KCWI). We recover their star formation histories, finding that all except one of our cEs are old and metal rich, with both age and metallicity decreasing toward their outer radii. We also use the integrated values within one effective radius to study different scaling relations. Comparing our cEs with others from the literature and from simulations we reveal the formation channel that these galaxies might have followed. All our cEs are fast rotators, with relatively high rotation values given their low ellipticites. In general, the properties of our cEs are very similar to those seen in the cores of more massive galaxies, and in particular, to massive compact galaxies. Five out of our six cEs are the result of stripping a more massive (compact or extended) galaxy, and only one cE is compatible with having been formed intrinsically as the low-mass compact object that we see today. These results further confirm that cEs are a mixed-bag of galaxies that can be formed following different formation channels, reporting for the first time an evolutionary link within the realm of compact galaxies (at all stellar masses).

中文翻译：

---

低质量紧凑椭圆星系：使用 Keck Cosmic Web Imager 进行空间分辨的恒星种群和运动学

我们使用来自 Keck Cosmic Web Imager (KCWI) 的光谱学展示了六个紧凑椭圆星系 (cE) 样本的恒星群和运动学的空间分辨二维图和径向趋势。我们恢复了它们的恒星形成历史，发现除了我们的一个 cE 之外，所有的恒星都是古老且富含金属的，随着年龄和金属丰度向它们的外半径递减。我们还使用一个有效半径内的积分值来研究不同的缩放关系。将我们的 cE 与文献和模拟中的其他 cE 进行比较，我们揭示了这些星系可能遵循的形成通道。我们所有的 cE 都是快速旋转器，由于椭圆度较低，旋转值相对较高。一般来说，我们的 cEs 的特性与在更大质量星系的核心中看到的特性非常相似，尤其是对于巨大的致密星系。我们六个 cE 中有五个是剥离更大质量（致密或扩展）星系的结果，只有一个 cE 与我们今天看到的本质上形成的低质量致密天体兼容。这些结果进一步证实，cEs 是一个混合星系，可以按照不同的形成通道形成，首次报告了致密星系（所有恒星质量）领域内的进化联系。