Related papers: A Dimensional study of Disk Galaxies
We investigate the effect of a cosmological constant $\Lambda$ on the geometry generated by a two-dimensional disclination in a conformal metric framework. For $\Lambda>0$, we obtain an exact analytic solution of the Liouville-type…
We aim to use statistical analysis of a large number of various galaxies to probe, model, and understand relations between different galaxy properties and magnetic fields. We have compiled a sample of 55 galaxies including low-mass dwarf…
Observed galactic disks have specific angular momenta similar to expectations for typical dark matter halos in $\Lambda$CDM. Cosmological hydrodynamical simulations have recently reproduced this similarity in large galaxy samples by…
A model of a galactic disk is presented which extends the homogeneous one zone models by incorporating propagation of material and energy in the disk. For reasonable values of the parameters the homogeneous steady state is unstable to the…
Catalogues of galaxies, clusters of galaxies and superclusters - sources of information to study the large-scale structure of the Universe are reviewed. The power spectrum of density perturbations, and the correlation function are discussed…
We discussed the dynamics of cosmological models in which the cosmological constant term is a time dependent function through the scale factor $a(t)$, Hubble function $H(t)$, Ricci scalar $R(t)$ and scalar field $\phi(t)$. We considered…
I discuss the Hubble parameter $H_0$, the age of the universe $t_0$, the density $\Omega_0$, and the cosmological constant $\Lambda$. To focus the discussion, I concentrate on the issue of the value of the density $\Omega_0$ in currently…
Recent advances in our understanding of massive star formation have made clear the important role of protostellar disks in mediating accretion. Here we describe a simple, semi-analytic model for young, deeply embedded, massive accretion…
We study the neutral hydrogen properties of a sample of 20 bulgeless disk galaxies (Sd - Sdm Hubble types), an interesting class that can be used to constrain galaxy formation and evolution, especially the role of mergers versus internal…
We use numerical simulations to investigate the orientation of the angular momentum axis of disk galaxies relative to their surrounding large scale structure. We find that this is closely related to the spatial configuration at turnaround…
We investigate the stellar angular momentum of galaxies across the Hubble sequence from the CALIFA survey. The distribution of CALIFA elliptical and lenticular galaxies in the $\lambda_{\rm Re}-\epsilon_{\rm e}$ diagram is consistent with…
The Lin and Pringle model (1987) of galactic disk formation postulates that if star formation proceeds on the same timescale as the viscous redistribution of mass and angular momentum in disk galaxies, then the stars attain an exponential…
(Abridged) Several aspects of the evolution of star-forming galaxies are studied using measures of the 2-dimensional surface brightness profile of a sample of 341 faint objects selected from the CFRS and LDSS redshift surveys that have been…
The disk components of galaxies generally show an exponential profile extending over several scale lengths, both in mass and star-formation rate, but the physical origin is not well understood. We explore a physical model in which the…
Galaxy formation models typically assume that the size and rotation speed of galaxy disks are largely dictated by the mass, concentration, and spin of their surrounding dark matter haloes. Equally important, however, are the fraction of…
Observational constraints guide one forcefully to examine models in which the matter density is substantially less than critical density. Particularly noteworthy are those which are consistent with inflation. For these models, microwave…
The Hubble constant can be constrained using the time delays between multiple images of gravitationally lensed sources. In some notable cases, typical lensing analyses assuming isothermal galaxy density profiles produce low values for the…
The galaxy cluster power spectrum and mass/temperature functions are currently the most precise observational tools for constraining the theory of the formation of large scale structure (LSS) in the Universe. Complementing these tests by…
In this work we introduce a physically motivated method of performing disc/spheroid decomposition of simulated galaxies, which we apply to the Eagle sample. We make use of the HEALPix package to create Mollweide projections of the angular…
To break the degeneracy among galactic stellar components, we extract kinematic structures using the framework described in Du et al. (2019, 2020). For example, the concept of stellar halos is generalized to weakly-rotating structures that…