相关论文: Structure and Dynamics of the Coma Cluster
We have studied 116 bright galaxies from the Coma cluster brighter than $m_{r}=17$ mag. From a quantitative morphological analysis we find that the scales of the disks are smaller than those of field spiral galaxies. There is a correlation…
We present a detailed analysis of the kinematics of 112 stars that mostly comprise the high velocity S-cluster and orbit the super massive black hole SgrA* at the center of the Milky Way. For 39 of them orbital elements are known, for the…
Deep images of the Centaurus and Coma clusters reveal two spectacular arcs of diffuse light that stretch for over 100 kpc, yet are just a few kpc wide. At a surface brightness of m_b \sim 27-28th arcsec^-2, the Centaurus arc is the most…
We present a detailed morphological analysis of the galaxy populations in the first two clusters to be completed in an extensive observational study of nine high-redshift clusters of galaxies (Oke, Postman & Lubin 1998). These two clusters,…
Ultra-diffuse galaxies (UDGs) are spatially extended, low surface brightness stellar systems with regular elliptical-like morphology found in a wide range of environments. Studies of the internal dynamics and dark matter content of UDGs…
We investigate the distribution and velocity field of galaxies situated in a band of 100 by 20 degrees centered on M87 and oriented along the Local supercluster plane. Our sample amounts 2158 galaxies with radial velocities less than 2000…
We examine gravitational lensing constraints on the structure of galaxy clusters and compare them with the results of cosmological N-body simulations of cluster formation in cold dark matter (CDM) dominated universes. We find that cluster…
The distributions of peculiar velocities of rich clusters and of groups of galaxies are investigated for different cosmological models and are compared with observations. Four cosmological models are studied: standard ($\Omega=1$) CDM,…
The recent microcalorimetric X-ray observations of the Coma cluster by XRISM have sparked active discussion regarding the physical origin of its gas velocity features. Here, we demonstrate that an off-axis minor merger in its early phase…
Context: Open clusters' dynamical evolution is driven by stellar evolution, internal dynamics and external forces, which according to dynamical simulations, will evaporate them in a timescale of about 1 Ga. However, about 10\% of the known…
We present the study of a large sample of early-type dwarf galaxies in the Coma cluster observed with DEIMOS on the Keck II to determine their internal velocity dispersion. We focus on a subsample of 41 member dwarf elliptical galaxies for…
We have obtained new redshifts for 265 objects in the central 48~$\times$~25~arcmin$^2$ region of the Coma cluster. When supplemented with literature data, our redshift sample is 95~\% complete up to a magnitude b$_{26.5}$=18.0 (the…
Close to its center, the bulgeless galaxy NGC 2139 hosts a star cluster that is younger and less massive than any actual nuclear star cluster (NC) studied so far. We have measured the H-alpha velocity field around the photometric center of…
We present the results of a new spectroscopic and photometric survey of the hot X-ray cluster 1E0657-56, at z=0.296. We determine the presence of a low velocity dispersion subcluster, which is offset from the main cluster position by 0.7…
We resolve a significant fraction of globular clusters (GCs) in NGC 4921, the brightest spiral galaxy in Coma. Also we find a number of extended bright star clusters (star complexes) in the spur region of the arms. The latter are much…
There has been plenty of observational evidence of cluster galaxy evolution. However, it has been difficult to identify the origin of the cluster galaxy evolution. Here we show that gravitational interaction/friction between galaxies is the…
We present a dynamical analysis of the galaxy cluster AC114 based on a catalogue of 524 velocities. Of these, 169 (32%) are newly obtained at ESO (Chile) with the VLT and the VIMOS spectrograph. Data on individual galaxies are presented and…
We present a detailed analysis of the kinematics of the Galactic globular cluster NGC 6397 based on more than ~18,000 spectra obtained with the novel integral field spectrograph MUSE. While NGC 6397 is often considered a core collapse…
(ABRIDGED) We use high resolution (~0.1") F814W ACS images from the HST ACS Treasury survey of the Coma cluster at z~0.02 to study bars in massive disk galaxies (S0s), and in dwarf galaxies in the Coma core. Our study helps constrain the…
In this study, we present a comprehensive analysis of the structural, astrophysical, and dynamical properties of eight open clusters: NGC 559, NGC 1817, NGC 2141, NGC 7245, Ruprecht 15, Ruprecht 137, Ruprecht 142, and Ruprecht 169, using…