Related papers: Properties of `Superthin' Galaxies
We present a detailed analysis of the global and fine structure of four middle-mass disc galaxies obtained from simulations in a $\Lambda$CDM scenario. These objects have photometric D/T ratios in good agreement with those observed for…
We probe the disk structure of the nearby, massive, edge-on spiral galaxy NGC 891 with sub-arcsecond resolution JHKs-band images covering ~+/-10 kpc in radius and +/-5 kpc in height. We measure intrinsic surface brightness profiles using…
We consider seven distant galaxies with clearly evident spiral structure from HST images. Three of these were chosen from Vogt et al. (1996) (VFP) and have measured rotational velocities. Five were chosen from the Medium Deep Survey and are…
It is well established that many galaxies, like our Milky Way, exhibit spiral patterns. The entire galactic disc rotates about the galactic centre with different speeds; higher closer to the centre, lower at greater distances - that is,…
Since 2015 there has been a great deal of interest in a supposed new class of galaxy called Ultra Diffuse Galaxies (UDGs). These are large systems with sizes $> 1.5$ kpc and have surface brightness values which are $\mu > 25$ mag…
In our hierarchical structure-formation paradigm, the observed morphological evolution of massive galaxies -- from rotationally-supported discs to dispersion-dominated spheroids -- is largely explained via galaxy merging. However, since…
I briefly review the growing evidence that thick stellar disks surround most edge-on disk galaxies. Recent studies show that these extragalactic thick disks have old ages, low metallicities, long scale lengths, and moderately flattened…
Passive spiral galaxies - unusual galaxies with spiral morphologies but without any sign of on-going star formation - have recently been shown to exist preferentially in cluster infalling regions. This discovery directly connects passive…
Gravitational lensing studies suggest that the Universe may contain a population of dark galaxies; we investigate this intriguing possibility and propose a mechanism to explain their nature. In this mechanism a dark galaxy is formed with a…
Giant Low Surface Brightness (GLSB) galaxies are amongst the most massive spiral galaxies that we know of in our Universe. Although they fall in the class of late type spiral galaxies, their properties are far more extreme. They have very…
The flatness of the rotation curve inside spiral galaxies is interpreted as the imprint of a halo of invisible matter. Using the deepest observations of distant galaxies, we have investigated how large disks could have been formed.…
We study the gravitational lensing effects of spiral galaxies by taking a model of the Milky Way and computing its lensing properties. The model is composed of a spherical Hernquist bulge, a Miyamoto-Nagai disc and an isothermal halo. As a…
Ultra-Diffuse Galaxies are both extreme products of galaxy evolution and extreme environments in which to test our understanding of star formation. In this work, we contrast the spatially resolved star formation activity of a sample of 22…
We estimate the masses of disks of galaxies using the marginal gravitational stability criterion and compare them with the photometrical disk mass evaluations. The comparison reveals that the stellar disks of most of spiral galaxies we…
A particular population of galaxies have drawn much interest recently, which are as faint as typical dwarf galaxies but have the sizes as large as $L^*$ galaxies, the so called "ultra-diffuse galaxie" (UDGs). The lack of tidal features of…
We study gravitational lensing by spiral galaxies, using realistic models consisting of halo, disk, and bulge components combined to produce a flat rotation curve. Proper dynamical normalization of the models is critical because a disk…
We present first results concerning the metallicities and stellar populations of galaxies formed in a cosmologically motivated simulation. The calculations include dark matter, gas dynamics, radiation processes, star formation, supernovae…
We study the chemical and spectro-photometric evolution of galactic disks with detailed models calibrated on the Milky Way and using simple scaling relations, based on currently popular semi-analytic models of galaxy formation. We compare…
Thick disks appear to be common in external large spiral galaxies and our own Milky Way also hosts one. The existence of a thick disk is possibly directly linked to the formation history of the host galaxy and if its properties is known it…
The formation and evolution of galactic disks is particularly important for understanding how galaxies form and evolve, and the cause of the variety in which they appear to us. Ongoing large surveys, made possible by new instrumentation at…