Related papers: Confronting Scaling Relations of Spiral Galaxies w…
The rotation velocity asymmetry v observed in spiral galaxy HI rotation curves linearly correlates with the effective potential force from the 10 closest neighboring galaxies normalized for the test particle mass and the gravitational…
In a previous work (Mbelek 2001), we modelled the rotation curves (RC) of spiral galaxies by including in the equation of motion of the stars the dynamical terms from an external real self-interacting scalar field, $\psi$, minimally coupled…
A century ago, in 1911 and 1913, Plummer and then Reynolds introduced their models to describe the radial distribution of stars in `nebulae'. This article reviews the progress since then, providing both an historical perspective and a…
We investigate colors and mass-to-light ratios ($M/L$s) of the bulges and disks for 28 nearby spiral galaxies with various morphological types of Sab to Scd, using images in optical and near-infrared ($V$, $I$, and $J$) bands and published…
We present a simple heuristic model to demonstrate how feedback related to the galaxy formation process can result in a scale-dependent bias of mass versus light, even on very large scales. The model invokes the idea that galaxies form…
The outer disks of galaxies present a unique laboratory for studying the process of disk formation. A considerable fraction of observed disks exhibit a break in their surface brightness profiles. The ubiquity of these features points to a…
Gravitational instabilities play a primary role in shaping the clumpy structure and powering the star formation activity of gas-rich high-redshift galaxies. Here we analyse the stability of such systems, focusing on the size and mass ranges…
Correlations among the independently measured physical properties of globular clusters (GCs) can provide powerful tests for theoretical models and new insights into their dynamics, formation, and evolution. We review briefly some of the…
We perform numerical simulations of the gravitational collapse of a spherically symmetric scalar field. For those data that just barely do not form black holes we find the maximum curvature at the position of the central observer. We find a…
In our modern understanding of galaxy formation, every galaxy forms within a dark matter halo. The formation and growth of galaxies over time is connected to the growth of the halos in which they form. The advent of large galaxy surveys as…
The fact that galaxy distribution exhibits fractal properties is well established since twenty years. Nowadays, the controversy concerns the range of the fractal regime, the value of the fractal dimension and the eventual presence of a…
Recent studies have shown that massive galaxies in the distant universe are surprisingly compact, with typical sizes about a factor of three smaller than equally massive galaxies in the nearby universe. It has been suggested that these…
We use deep r-band photometry and Halpha rotation curves for a sample of 290 late-type spirals to model their mass distribution within the optical radius. We examine luminosity profile decompositions into bulge and disk carefully and…
The structural parameters of a galaxy can be used to gain insight into its formation and evolution history. In this paper, we strive to compare the Milky Way's structural parameters to other, primarily edge-on, spiral galaxies in order to…
This series of papers is dedicated to a new technique to select galaxies that can act as standard rods and standard candles in order to perform geometrical tests on large samples of high redshift galaxies to constrain different cosmological…
I review at the non-specialist level recent progress in the study of the large-scale structure of the Universe, covering the following areas: (1) Results from recently completed or ongoing redshift surveys of galaxies and X-ray clusters;…
A major goal of contemporary astrophysics is understanding the origin of the most massive galaxies in the universe, particularly nearby ellipticals and spirals. Theoretical models of galaxy formation have existed for many decades, although…
The standard picture for the formation of disk galaxies has come to face a number of problems related to angular momentum. Numerical simulations produce disks that are too small, and analytical models predict too much low angular momentum…
The timescale for star formation, a measure of how quickly neutral gas is being converted to stars, is considerably longer than typical dynamical timescales associated with a galactic disk. For purposes of modeling galaxy evolution,…
A detailed analysis of the galaxy distribution in the Southern Sky Redshift Survey (SSRS) by means of the multifractal or scaling formalism is presented. It is shown that galaxies cluster in different ways according to their morphological…