In the current epoch, one of the main mechanisms driving the growth of galaxy clusters is the continuous accretion of group-scale halos. In this process, the ram pressure applied by the hot intracluster medium on the gas content of the infalling group is responsible for stripping the gas from its dark-matter halo, which gradually leads to the virialization of the infalling gas in the potential well of the main cluster. Using deep wide-field observations of the poor cluster Hydra A/A780 with XMM-Newton and Suzaku, we report the discovery of an infalling galaxy group 1.1 Mpc south of the cluster core. The presence of a substructure is confirmed by a dynamical study of the galaxies in this region. A wake of stripped gas is trailing behind the group over a projected scale of 760 kpc. The temperature of the gas along the wake is constant at kT ~ 1.3 keV, which is about a factor of two less than the temperature of the surrounding plasma. We observe a cold front pointing westwards compared to the peak of the group, which indicates that the group is currently not moving in the direction of the main cluster, but is moving along an almost circular orbit. The overall morphology of the group bears remarkable similarities with high-resolution numerical simulations of such structures, which greatly strengthens our understanding of the ram-pressure stripping process.
Looking into the faintEst WIth MUSE (LEWIS): Exploring the nature of ultra-diffuse galaxies in the Hydra I cluster III. Untangling UDG 32 from the stripped filaments of NGC 3314A with multi-wavelength data
Intracluster globular clusters as tracers of the mass assembly of the Hydra I galaxy cluster
European Southern Observatory（欧洲南方天文台）；Universitätssternwarte der Ludwig-Maximilians Universität（路德维希-马克西米利安大学大学天文台）；INAF – Astronomical Observatory of Capodimonte（意大利国家天体物理研究所卡波迪蒙特天文台）；Max-Planck-Institut für Extraterrestrische Physik（马克斯·普朗克地外物理学研究所）；INAF – Astronomical Observatory of Abruzzo（意大利国家天体物理研究所阿布鲁佐天文台）；Gran Sasso Science Institute（格兰萨索科学研究所）
Instituto de Astrofísica de Andalucía (CSIC)（安达卢西亚天体物理研究所）；Chalmers University of Technology（查尔姆斯理工大学）；ASTRON, the Netherlands Institute for Radio Astronomy（荷兰射电天文研究所）；University of Wisconsin-Madison（威斯康星大学麦迪逊分校）；Zhejiang Laboratory（浙江实验室）；University of Cape Town（开普敦大学）；University of Hawaii at Hilo（夏威夷大学希洛分校）；Western Sydney University（西悉尼大学）；Swinburne University of Technology（斯威本科技大学）；University of the Western Cape（西开普大学）
Looking into the faintEst WIth MUSE (LEWIS): Exploring the nature of ultra-diffuse galaxies in the Hydra-I cluster. VI. A star-forming UDG in Hydra I: a rare UDG or a transition phase?
University of Naples “Federico II”（那不勒斯费德里科二世大学）；Armagh Observatory and Planetarium（阿马赫天文台和天文馆）；Gran Sasso Science Institute（格兰萨索科学研究所）；Finnish Centre for Astronomy with ESO, (FINCA), University of Turku（图尔库大学芬兰ESO天文中心）；Tuorla Observatory, Department of Physics and Astronomy, University of Turku（图尔库大学物理与天文学系图奥拉天文台）；Turku Collegium for Science（图尔库科学学院）
The shocking features in the closest rich galaxy cluster Norma
Xiamen University（厦门大学）；University of Alabama in Huntsville（阿拉巴马大学亨茨维尔分校）；Rhodes University（罗德岛大学）；INAF-Osservatorio Astronomico di Cagliari（意大利国家天体物理研究所卡利亚里天文台）；Gustavus Adolphus College（古斯塔夫斯阿道夫学院）；Australia Telescope National Facility, CSIRO（澳大利亚望远镜国家设施，CSIRO）；Western Sydney University（西悉尼大学）
A Consistent Comparison of Intracluster Light Assembly in Simulations I. Redshift Evolution and Progenitor Galaxies
University of Nottingham（诺丁汉大学）；École Polytechnique Fédérale de Lausanne (EPFL)（洛桑联邦理工学院）；Universidad Autónoma de Madrid（马德里自治大学）；Royal Observatory, Edinburgh（爱丁堡皇家天文台）
