Related papers: Color Differences between Clockwise and Counterclo…
We search for bulk counterrotation of the gas and stars in 67 galaxies of all types and a wide range of luminosities. Bulk counterrotation characterizes \~25-30% of E/S0's with extended gas, but at most a few percent of Sa-Sbc spirals. For…
The Galaxy inner parts are generally considered to be optically symmetric, as well as kinematically symmetric for most massive early-type galaxies. At the lower-mass end, many galaxies contain lots of small patches in their velocity maps,…
The properties of galaxies depend on their environment: red, passive elliptical galaxies are usually located in denser environments than blue, star-forming spiral galaxies. This difference in galaxy populations can be detected at all scales…
We have performed a large observing campaign of intermediate-redshift disk galaxies including spectroscopy with the FORS instruments of the VLT and imaging with the Advanced Camera for Surveys onboard the HST. Our data set comprises 113…
Galaxies are not distributed randomly throughout space but are instead arranged in an intricate "cosmic web" of filaments and walls surrounding bubble-like voids. There is still no compelling observational evidence of a link between the…
We compare the structural properties of two classes of galaxies at intermediate redshift: those in dynamically close galaxy pairs, and those which are isolated. Both samples are selected from the CNOC2 Redshift Survey, and have redshifts in…
Spirals in galaxies have long been thought to be caused by gravitational instability in the stellar component of the disk, but discerning the precise mechanism had proved elusive. Tidal interactions, and perhaps bars, may provoke some…
Recent independent observations using several different telescope systems an analysis methods have provided evidence of parity violation between the number of galaxies that spin in opposite directions. On the other hand, other studies…
I briefly explore some relevant connections and differences between the evolutionary paths of dwarf galaxies and globular clusters.
Our Milky Way Galaxy is a typical large spiral galaxy, representative of the most common morphological type in the local Universe. We can determine the properties of individual stars in unusual detail, and use the characteristics of the…
We present optical and millimetric data for 47 intermediate Hubble type spiral galaxies located either in dense environments or in the field. We compare correlations between global parameters, such as far-infrared luminosity, blue…
The orientations of brightest cluster galaxies (BCGs) and their host clusters tend to be aligned, but the mechanism driving this is not clear. To probe the role of cluster mergers in this process, we quantify alignments of 38 BCGs in 22…
A homogeneous sample of galaxy redshifts in the core regions (R < 0.5 h$^{-1}$ Mpc) of 12 clusters is used to measure the frequency of substructure with different tests. In 50 % of the cases substructure is detected, a frequency which…
There is now strong evidence that the metal-rich globular clusters (GC) near the center of our Galaxy are associated with the Galactic bulge rather than the disk as previously thought. Here we extend the concept of bulge GCs to the GC…
We consider the roles of two widely invoked mechanisms for the metallicity-luminosity correlation among late-type galaxies: higher astration level and decreasing efficiency of heavy-element loss with increasing luminosity. We find that both…
We present a detailed photometric study and measurements of spiral arm pitch angles for a sample of 50 non-barred or weakly barred grand-design spiral galaxies selected from Sloan Digital Sky Survey. In order to find pitch angles, we used a…
We describe the use of partially overlapping galaxies to provide direct measurements of the effective absorption in galaxy disks, independent of assumptions about internal disk structure. The non-overlapping parts of the galaxies and…
We present a quantitative measure of the internal color dispersion within galaxies, which quantifies differences in morphology as a function of wavelength. We apply this statistic to a local galaxy sample with archival images at 1500 and…
It is well known that Globular cluster systems are different among galaxies. Here we test to which degree these differences remain on the scale of galaxy clusters by comparing the globular clusters (GCs) in optical surveys of the Virgo…
The colors of globular clusters in most of large elliptical galaxies are bimodal. This is generally taken as evidence for the presence of two cluster subpopulations that have different geneses. However, here we find that, because of the…