Related papers: Beyond the sphericity assumption in dynamical HI m…
We review the formalism and applications of the halo-based description of nonlinear gravitational clustering. In this approach, all mass is associated with virialized dark matter halos; models of the number and spatial distribution of the…
The present work is devoted to study the dynamical evolution of the galaxies in scalar-GaussBonnet gravity in relationship with the MOND paradigm. This study is useful for giving meaning to the presence of a new gravitational constant. The…
The dynamical and virial mass of the Milky Way galaxy is estimated using latest high precision stellar halo and dwarf galaxy satellite kinematics. The new data suggest the Galaxy is a highly compact, classically thermalized object.…
We analyze the structural and dynamical properties of disk-like objects formed in fully consistent cosmological simulations with an inefficient star formation algorithm. Comparison with data of similar observable properties of spiral…
Spiral galaxies are studied using a simple global disc model as a means for approximate determination of mass profiles. Based on rotation curves and the amount of gas (HI+He), we find global surface mass densities consistent with…
The positions of images produced by the gravitational lensing of background sources provide unique insight in to galaxy-lens mass distribution. However, even quad images of extended sources are not able to fully characterize the central…
The images of relativistic jets from extragalactic sources produced by gravitational lensing by galaxies with different mass surface density distributions are modeled. In particular, the following models of the gravitational lens mass…
We present high-resolution optical velocity fields from DensePak integral field spectroscopy, along with derived rotation curves, for a sample of low surface brightness galaxies. In the limit of no baryons, we fit the NFW and…
Reducing theoretical uncertainties in Galactic dark matter (DM) searches is an important challenge as several experiments are now delving into the parameter space relevant to popular (particle or not) candidates. Since many DM signal…
(Abridged). It has been recently shown that random motions of the neutral Hydrogen gas of the Triangulum galaxy (M33) exhibit a bisymmetric perturbation which is aligned with the minor axis of the galaxy, suggesting a projection effect. To…
Detailed studies of galaxy formation require clear definitions of the structural components of galaxies. Precisely defined components also enable better comparisons between observations and simulations. We use a subsample of eighteen…
We report a tight linear relation between the HI circular velocity measured at 6 $R_{\rm e}$ and the stellar velocity dispersion measured within 1 $R_{\rm e}$ for a sample of 16 early-type galaxies with stellar mass between $10^{10}$ and…
The existence of "dark matter", inferred from the observed rotation curves of galaxies, is a hypothesis which is widely regarded as problematic. This paper proposes an alternative hypothesis based on the space-time geometry near a rotating…
Observations consistently show that elliptical galaxies follow a tight "fundamental plane" scaling relation between size, mean surface brightness and velocity dispersion, with the form $R \propto \sigma^{a}\mu^{b}$. This relation not only…
We present the mass models of 31 spiral and irregular nearby galaxies obtained using hybrid rotation curves (RCs) combining high resolution GHASP Fabry-Perot H$\alpha$ RCs and extended WHISP HI ones together with 3.4 $\mu$m WISE photometry.…
Modeling the mass distribution of galaxy-scale strong gravitational lenses is a task of increasing difficulty. The high-resolution and depth of imaging data now available render simple analytical forms ineffective at capturing lens…
Spiral waves in active media react to small perturbations as particle-like objects. Here we apply the asymptotic theory to the interaction of spiral waves with a localized inhomogeneity, which leads to a novel prediction: drift of the…
Using a new algorithm for estimating the actions of orbits a parametrised distribution function is automatically fitted to observational data for the solar neighbourhood. We adopt a gravitational potential that is generated by three discs…
We have used the Parkes Multibeam system and the Sloan Digital Sky Survey (SDSS) to assemble a sample of 195 galaxies selected originally from their HI signature to avoid biases against unevolved or low surface brightness objects. For each…
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…