Related papers: The galaxy alignment effect in Abell 1689: evoluti…
Using a sample of galaxy groups selected from the Sloan Digital Sky Survey Data Release 7 (SDSS DR7), we examine the alignment between the orientation of galaxies and their surrounding large scale structure in the context of the cosmic web.…
(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…
We study the photometric parameters of the bulges of galaxies of different Hubble types including ellipticals, lenticulars, early and late type spirals and early type dwarf galaxies. Analyzing the distributions of various photometric…
Galaxies are known to be aligned toward specific directions within the large-scale structure. Such alignment signals become important for controlling the systematics of weak lensing surveys and for constraining galaxy formation and…
We use galaxy groups selected from the Sloan Digital Sky Survey to examine the alignment between the orientation of the central galaxy (defined as the brightest group member) and the distribution of satellite galaxies. By construction, we…
Abell 2146 ($z$ = 0.232) consists of two galaxy clusters undergoing a major merger. The system was discovered in previous work, where two large shock fronts were detected using the $\textit{Chandra X-ray Observatory}$, consistent with a…
Abell 85 is a nearby (z=0.055) galaxy cluster that hosts a sloshing cool core, a feature commonly reported in relaxed clusters. However, the presence of multiple past and ongoing mergers indicates that it is an active node within the Abell…
Intrinsic alignments between galaxies and the large-scale structure contaminate galaxy clustering analyses and impact constraints on galaxy bias and the growth rate of structure in the Universe. This is the result of alignments inducing a…
We study the mean tidal coherence of galaxy environments as a function of intrinsic luminosity determined by the absolute $r$-band magnitude. The tidal coherence of a galaxy environment is estimated as the cosine of the angle between two…
We present a new estimate of the projected X-ray mass of Abell 1689 observed with Chandra, in an attempt to clarify the issue of whether or not there exists a discrepancy between X-ray and gravitational lensing mass estimates claimed in…
We present a weak shear analysis of the Abell 901/902 supercluster, composed of three rich clusters at z=0.16. Using a deep R-band image from the 0.5 x 0.5 degree MPG/ESO Wide Field Imager together with supplementary B-band observations, we…
We use Keck laser guide star adaptive optics imaging and exploit the magnifying effects of strong gravitational lensing (the effective resolution is FWHM ~ 200 pc) to investigate the sub-kpc scale of an intermediate-redshift (z = 0.63)…
We present a detection of the intrinsic galaxy alignments in the CAMELS suite of hydrodynamic simulations. We find that the alignment amplitude depends significantly on cosmological and supernova feedback parameters - specifically…
We report a new analysis of the Hubble Frontier Fields clusters Abell 2744 and MACS 0416 using wavelet decomposition to remove the cluster light, enabling the detection of highly magnified (>50x) galaxies a factor of 10x fainter in…
This paper presents some statistical correlations of 72 northern spiral galaxies. The results show that early-type spirals that are brighter, and thicker, and the axis ratios ($H_{z}/H_r$) of the disk tend to be smaller along the Hubble…
The statistical properties of the ellipticities of galaxy images depend on how galaxies form and evolve, and therefore constrain models of galaxy morphology, which are key to the removal of the intrinsic alignment contamination of…
The intrinsic alignment of galaxy shapes (by means of their angular momentum) and their cross-correlation with the surrounding dark matter tidal field are investigated using the 160 000, z=1.2 synthetic galaxies extracted from the…
We present the results of our analysis of the geometrical tidal tail characteristics for nearby and distant interacting galaxies. The sample includes more than two hundred nearby galaxies and about seven hundred distant ones. The distant…
We present first results of an all-sky observing program designed to improve the quality of the I band Tully-Fisher (TF) template and to obtain the reflex motion of the Local Group with respect to clusters to z = 0.06. We are obtaining…
Observations in the Hubble Deep Fields have been used to study the evolution of galaxy morphology over time. The majority of galaxies with z < 1 are seen to be disk like, whereas most objects with z > 2 appear to be either chaotic or…