Early-type dwarf galaxies constitute a prevalent population in the central regions of rich groups and clusters in the local Universe. These low-luminosity and low-mass stellar systems play a fundamental role in the assembly of the luminous galaxies observed today, according to the $Λ$CDM hierarchical theory. The origin of early-type dwarfs has been linked to the transformation of disk galaxies interacting with the intracluster medium, especially in dense environments. However, the existence of low-luminosity early-type galaxies in low-density environments presents a challenge to this scenario. This study presents a comprehensive photometric and spectroscopic analysis of the early-type dwarf galaxy CGCG014-074 using deep GEMINI+GMOS data, focusing on its peculiarities and evolutionary implications. CGCG014-074 exhibits distinct features, including a rotating inner disk, an extended stellar formation with a quiescent phase since about 2 Gyr ago, and the presence of boxy isophotes. From the kinematic analysis, we confirm CGCG014-074 as a nucleated early-type dwarf galaxy with embedded disk. The study of its stellar population parameters using different methods provides significant insights into the galaxy's evolutionary history. These results show an old and metal-poor nucleus ($\sim 9.3$ Gyr and $\mathrm{[Z/H]}\sim-0.84$ dex), while the stellar disk is younger ($\sim4.4$ Gyr) with a higher metallicity ($\mathrm{[Z/H]}\sim-0.40$ dex). These distinctive features collectively position CGCG014-074 as a likely building block galaxy that has evolved passively throughout its history.
Attaining Spectral Energy Distributions With Sub-Percent Uncertainties: All-Sky DA White Dwarf Spectrophotometric Standard Stars For Large Telescopes And Surveys
NSF’s National Optical Infrared Astronomy Research Laboratory（美国国家光学红外天文研究实验室）；The University of Arizona, Steward Observatory（亚利桑那大学斯图尔德天文台）；Institute of Astronomy and Kavli Institute for Cosmology, University of Cambridge（剑桥大学天文学研究所和卡弗里宇宙学研究所）；University of Illinois at Urbana-Champaign（伊利诺伊大学厄巴纳-香槟分校）；Space Telescope Science Institute（太空望远镜科学研究所）；INAF - Osservatorio Astronomico Capodimonte（意大利国家天体物理研究所卡波迪蒙特天文台）；The University of Arizona, Lunar and Planetary Laboratory（亚利桑那大学月球与行星实验室）
Origin of stellar prolate rotation in a cosmologically simulated faint dwarf galaxy
在矮星系中，恒星的长轴自转是相当罕见的，只有两个已知的本星系群中的星系显示出这样的特征（凤凰和和II）。宇宙学模拟显示，在大质量的早型星系中，长轴自转可能是由主要的合并引起的。然而，这种运动学在矮星系制度的起源只被探索使用理想化的模拟。本文利用流体动力学宇宙学方法对恒星质量介于$3\times10^5$和$5\times10^8$ M $_{\odot}$之间的矮星系进行了模拟，探讨了长旋星系的形成.在$27$矮星中，只有一个系统显示出围绕主轴的明显旋转，其罪魁祸首是$z=1.64$的主要合并，这导致了从扁圆到长轴配置的转变。有趣的是，这个星系显示出一个陡峭的金属丰度梯度，让人想起在凤凰和和II测量的：这是合并事件的结果，动态加热老的，金属贫乏的恒星，和中心集中的残余恒星形成。矮星系中的大合并为这种奇特系统的形成提供了一个可行的解释，其特征是陡峭的金属丰度梯度和长轴旋转。
Implications for the origin of dwarf early-type galaxies: a detailed look at the isolated rotating dwarf early-type galaxy CG 611, with ramifications for the Fundamental Plane's (S_K)^2 kinematic scaling and the spin-ellipticity diagram
