In this study we investigate the optical photometric properties of early-type galaxies in the Virgo cluster core region, by analysing their location on the colour magnitude relation (CMR) and the structural scaling relations down to faint magnitudes, and by constructing the luminosity function to compare it with theoretical expectations. We visually select potential cluster members based on morphology and angular size, excluding spiral galaxies. A photometric analysis has been carried out for 295 galaxies, using surface brightness profile shape and colour as further criteria to identify probable background contaminants. 216 galaxies are considered to be certain or probable Virgo cluster members. Our study reveals 77 galaxies not catalogued in the VCC (with 13 of them already found in previous studies) that are very likely Virgo cluster members because they follow the Virgo CMR and exhibit low Sersic indices. Those galaxies reach -8.7 mag in V band. The CMR shows a clear change in slope from dEs to dSphs, while the scatter of the CMR in the dSph regime does not increase significantly. Our sample might, however, be somewhat biased towards redder colours. The scaling relations given by the dEs appear to be continued by the dSphs indicating a similar origin. The observed change in the CMR slope may mark the point at which gas loss prevented significant metal enrichment. The almost constant scatter around the CMR possibly indicates a short formation period, resulting in similar stellar populations. The luminosity function shows a Schechter function's faint end slope of -1.50\pm0.17, implying a lack of galaxies related to the expected number of low-mass dark matter haloes from theoretical models. Our findings could be explained by suppressed star formation in low-mass dark matter halos or by tidal disruption of dwarfs in the dense core region of the cluster.
The ACS Fornax Cluster Survey. IV. Deprojection of the Surface Brightness Profiles of Early-Type Galaxies in the Virgo and Fornax Clusters: Investigating the "Core/Power-Law Dichotomy"
How do the LIGO-Virgo-KAGRA's Heavy Black Holes Form? No evidence for core-collapse Intermediate-mass black holes in GWTC-4
Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Sciences（中国科学院紫金山天文台暗物质与空间天文重点实验室）；Institute for Theoretical Physics and Cosmology, Zhejiang University of Technology（浙江工业大学理论物理与宇宙学研究所）；Department of Physics, Anhui Normal University（安徽师范大学物理系）
Stellar Kinematics and Structural Properties of Virgo Cluster Dwarf Early-Type Galaxies from the SMAKCED Project. I. Kinematically Decoupled Cores and Implications for Infallen Groups in Clusters
Velocity fields and turbulence from cosmic filaments to galaxy clusters
Université Paris-Saclay（巴黎萨克雷大学）；CNRS（法国国家科学研究中心）；Institut d’Astrophysique Spatiale（天体物理研究所）；The Open University of Israel（以色列开放大学）；Kapteyn Astronomical Institute（卡普坦天文研究所）；University of Groningen（格罗宁根大学）；Université de Lille（里尔大学）；Centrale Lille（里尔中央理工学院）；CRIStAL（晶体与材料研究中心）
The Next Generation Virgo Cluster Survey - Infrared (NGVS-IR): I. A new Near-UV/Optical/Near-IR Globular Cluster selection tool
NGVS-IR项目（下一代室女座巡天-红外）是对室女星系团进行的连续近红外成像巡天。它补充了室女座的光学广域调查（NGVS）。NGVS-IR的当前状态包括以M87为中心的4度^2的KS波段图像，以及覆盖M49和M87之间区域的16度^2的J和KS波段图像。在本文中，我们给出了以室女座核心区域为中心的中心4度^2的观测结果。这些数据是用加拿大-法国-夏威夷望远镜上的WIRCam获得的，总积分时间为41小时，分布在34个连续的瓦片中。一个特定的调查策略被设计来解释扩展的星系，同时仍然测量调查区域内准确的天空亮度。当仅使用视宁度优于0.7”（视宁度中值为0.54”）的图像时，点源检测的平均5σ极限星等为Ks =24.4 AB mag，50%完整性极限为Ks=23.75 AB mag。在这些图像中，星团的分辨率很低，其中发现了μ_Ks=24.4 AB等角秒^-2的室女座星系。结合Ks数据与光学和紫外数据，我们建立了uiK色-色图，它允许一个非常干净的基于颜色的选择球状星团在室女座。这一诊断图将为继续探索室女座的光度和运动学子结构所需的光谱后续活动提供可靠的球状星团候选者，并将有助于设计未来在河外系统中搜索球状星团的计划。配备了这个强大的新工具，未来基于uiK图的NGVS-IR研究将解决室女座星系及其周围的扩展结构和紧凑恒星系统的映射和分析。
Spitzer IRAC Low Surface Brightness Observations of the Virgo Cluster
我们目前的3.6和4.5微米斯皮策IRAC成像超过0.77平方度的室女星系团核心的目的是了解低表面亮度的形成机制的集群内的光功能。比信号高出数百倍的仪器和天体物理背景被仔细表征和去除。我们研究了巨大椭圆星系M87的团内光羽和外晕。对于两个团内光羽，我们使用光学颜色来限制它们的年龄分别大于3和5 Gyr。IRAC通量的上限限制了质量的上限，光学检测限制了质量的下限。在这第一次测量团内轻羽流的质量时，我们发现我们所覆盖的两个羽流的质量范围分别为5.5 x 10^8 - 4.5 x 10^9和2.1 x 10^8 - 1.5 x 10^9太阳质量。考虑到它们的预期寿命很短，以及这些类型的流的恒定生产率，在室女座的一生中，它们可以解释星团的ICL总含量，这意味着我们不需要调用ICL形成机制，而不是引力机制导致明亮的羽流。我们还研究了巨大的椭圆形M87的外晕。从M87的内晕到外晕（160 Kpc）的颜色轮廓与平坦或光学蓝色梯度一致，其中蓝色梯度可能是由于更年轻或更低的金属量恒星在更大的半径。由红外和光学颜色预测的年龄的相似性（>几Gyr）表明，光学测量并没有强烈的尘埃消光的影响。
A hydrodynamical CLONE of the Virgo cluster: II. Confronting observed and synthetic galaxy population twins in a dense environment
Univ. Lille, CNRS, Centrale Lille, UMR 9189 CRIStAL（里尔大学）；Université Paris-Saclay, CNRS, Institut d’Astrophysique Spatiale（巴黎萨克雷大学）；University of Birmingham School of Physics and Astronomy（伯明翰大学）；Institut d’Astrophysique de Paris, UMR 7095, Sorbonne Université, CNRS（索邦大学）；Univ Lyon, Univ Lyon1, Ens de Lyon, CNRS, Centre de Recherche Astrophysique de Lyon UMR5574（里昂大学）；Universidad Autónoma de Madrid（马德里自治大学）；International Centre for Radio Astronomy Research, University of Western Australia（西澳大利亚大学）
