Related papers: Disturbed isolated galaxies: indicators of a dark …
Searching for lopsided/interacting objects among ~1500 isolated galaxies yields only eight strongly disturbed galaxies which may be explained as a result of their interaction with massive dark objects. We present results of spectral and…
This paper argues that there is a large population of dark galaxies which reveals its presence by the gravitational lensing of quasars, and outnumbers normal galaxies by around 3:1. There are 8 double quasars with a separation greater than…
We present a list of 75 isolated late-type dwarf galaxies which have no neighbors with a relative radial velocity difference of less than 500 km/s or projected separations within 500 kpc. These were selected from $\sim$2000 dwarf galaxies…
In the standard cosmological model of galaxy evolution, mergers and interactions play a fundamental role in shaping galaxies. Galaxies that are currently isolated are thus interesting, allowing us to distinguish between internal and…
Galaxy triplets are interesting laboratories where we can study the formation and the evolution of small and large systems of galaxies. This study aims to investigate signs of interaction between the members of nine isolated galaxy triplet…
Gravitational lensing studies suggest that the Universe may contain a population of dark galaxies; we investigate this intriguing possibility and propose a mechanism to explain their nature. In this mechanism a dark galaxy is formed with a…
Isolated galaxies have not been a hot topic over the past four decades. This is partly due to uncertainties about their existence. Are there galaxies isolated enough to be interesting? Do they exist in sufficient numbers to be statistically…
We report a list of groups consisting of dwarf galaxies only. The sample contains 126 objects, mainly combined in pairs. The most populated group contains six dwarf galaxies. The majority of systems considered reside in the low-density…
The radial velocities are measured for 45 galaxies located in the neighborhoods of 29 likely isolated galaxies in a new catalog. We find that about 85% of these galaxies actually are well isolated objects. 4% of nearby galaxies with…
In order to understand nature of building blocks of galaxies in the early universe, we investigate "genuine irregular galaxies (GIGs)" in the nearby universe. Here, GIGs are defined as isolated galaxies without regular structures (spheroid,…
Compact groups of galaxies have posed a number of challenging questions. Intensive observational and theoretical studies are now providing answers to many of these, and at the same time, are revealing unexpected new clues about the nature…
We have updated the classification of late-type galaxies presented in the Catalog of Isolated Galaxies (KIG) using the advanced digital sky surveys. Our search for companions around 959 KIG galaxies revealed 141 neighbors associated with…
Dwarf galaxies have attracted increased attention in recent years, because of their susceptibility to galaxy transformation processes within rich galaxy clusters. Direct evidence for these processes, however, has been difficult to obtain,…
The recent detections of a large population of faint submillimetre sources, an excess halo gamma-ray background, and the extreme scattering events observed for extragalactic radio sources have been explained as being due to baryonic dark…
There are only a few ``dark galaxy'' candidates discovered to date in the local Universe. One of the most prominent of them is the SW component of a merging system HI 1225+01. On the other hand, the number of known very metal-poor gas-rich…
Spatial Fluctuations in the Cosmic Infrared Background have now been measured out to sub-degree scales showing a strong clustering signal from unresolved sources. We attempt to explain these measurement by considering faint galaxy…
We have completed a pilot survey imaging 15 SDSS selected void galaxies in HI in local (d=50 to 100 Mpc) voids. This small sample makes up a surprisingly interesting collection of galaxies, consisting of galaxies with asymmetric and…
We use a new fiber spectroscopic survey of 12 nearby, poor groups of galaxies to examine the dynamics and evolution of galaxies in these common, but poorly studied, environments. Some of our conclusions are: (1) The nine groups in our…
Cosmological models with cold dark matter composed of weakly interacting particles predict overly dense cores in the centers of galaxies and clusters and an overly large number of halos within the Local Group compared to actual…
Clusters of galaxies have a huge mass which can act as gravitational lenses. Galaxies behind clusters can be distorted to form arcs in images by the lenses. Herein a search was done for giant lensed arcs by galaxy clusters using the SDSS…