相关论文: Color Differences between Clockwise and Counterclo…
The PSCz redshift survey and the ongoing Two-Degree Field Galaxy Redshift Survey (2dFGRS) are used to look for luminosity dependence of galaxy clustering by measuring the two point correlation functions for sub-samples of the surveys. An…
In this article I study the distribution of spiral galaxies in the Sloan Digital Sky Survey (SDSS) to investigate whether the universe has an overall handedness. A preference for spiral galaxies in one sector of the sky to be left-handed or…
We present a systematic observational study of the spin alignment between galaxy groups and their central galaxies using a large spectroscopic sample from the Sloan Digital Sky Survey. Unlike previous studies based on morphology or major…
The light distribution in the disks of many galaxies is non-axisymmetric or `lopsided' with a spatial extent much larger along one half of a galaxy than the other, as in M101. Recent near-IR observations show that lopsidedness is common.…
A kinematical analysis applied to a sample of galaxy clusters indicates that the differences between the velocity distribution of elliptical and spiral galaxies are associated with the shape of their orbit families. The orbital anisotropies…
The stellar halos of spiral galaxies bear important chemo-dynamical signatures of galaxy formation. We present here the analysis of 89 semi-cosmological spiral galaxy simulations, spanning ~ 4 magnitudes in total galactic luminosity. These…
Cosmologists have often considered the Milky Way as a typical spiral galaxy, and its properties have considerably influenced the current scheme of galaxy formation. Here we compare the general properties of the Milky Way disk and halo with…
Recent observational results on the globular cluster systems of spiral galaxies are summarized. Although the number of spirals with well-studied GCSs is still small, new studies promise to increase it rapidly in the next few years. New…
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…
We study the mean environments of galaxies in the Sloan Digital Sky Survey as a function of rest-frame luminosity and color. Overdensities in galaxy number are estimated in $8 h^{-1} \mathrm{Mpc}$ and $1 h^{-1} \mathrm{Mpc}$ spheres…
In the past decade, an asymmetry in the large-scale distribution of galaxy spin directions has been observed in data from all relevant digital sky surveys, all showing a higher number of galaxies rotating in the opposite direction relative…
We find, from our study of binary spiral galaxies in the Sloan Digital Sky Survey Data Release 6, that the relative orientation of disks in binary spiral galaxies is consistent with their being drawn from a random distribution of…
A co-rotation radius is a key characteristic of disc galaxies that is essential to determine the angular speed of the spiral structure $\Omega_{p}$, and therefore understand its nature. In the literature, there are plenty of methods to…
We present a statistical study of optical warps in a sample of 540 galaxies, about five times larger than previous samples. About 40% of all late-type galaxies reveal S-shaped warping of their planes in the outer parts. Given the…
Previous observations have suggested non-random distribution of spin directions of galaxies at scales far larger than the size of a supercluster. Here I use $\sim1.7\cdot10^5$ spiral galaxies from SDSS and $3.3\cdot10^4$ spiral galaxies…
Galaxies are not randomly distributed across the universe but showing different kinds of alignment on different scales. On small scales satellite galaxies have a tendency to distribute along the major axis of the central galaxy, with…
(Abridged) We investigate optical and near-IR color gradients in a sample of 172 low-inclination galaxies spanning Hubble types S0--Irr. The colors are compared to stellar population synthesis models from which luminosity-weighted average…
Populations of young star clusters show significant differences even among "normal" disk galaxies. In this contribution I discuss how properties of young cluster systems are related to those of their host galaxies, based on a recent study…
We measure the projected density profile, shape and alignment of the stellar and dark matter mass distribution in 11 strong-lens galaxies. We find that the projected dark matter density profile - under the assumption of a Chabrier stellar…
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…