Related papers: Why are some galaxy disks extremely thin?
I discuss measurements of disk mass from non-circular streaming motions of gas in the barred galaxies NGC 3095 and NGC 4123. In these galaxies with strong shocks and non-circular motions, the inner regions must be disk-dominated to…
Eliptical and bulge galaxies share a tight correlation of velocity distribution to both luminosity and black hole mass. There are similar orbital speeds for all galaxies of a given luminosity including dark matter (DM) at large radii. The…
Breaks in the radial luminosity profiles of galaxies have been until now mostly studied averaged over discs. Here we study separately breaks in thin and thick discs in 70 edge-on galaxies using imaging from the Spitzer Survey of Stellar…
The Milky Way is a spiral galaxy comprising three main components: the Bulge, the Disk, and the Halo. Of particular interest is the Galactic disk, which holds a significant portion of the baryonic matter angular momentum and harbors at…
About two-thirds of present-day, large galaxies are spirals such as the Milky Way or Andromeda, but the way their thin rotating disks formed remains uncertain. Observations have revealed that half of their progenitors, six billion years…
We describe the use of partially overlapping galaxies to provide direct measurements of the effective absorption in galaxy disks, independent of assumptions about internal disk structure. The non-overlapping parts of the galaxies and…
The properties and star formation processes in the far-outer disks of nearby spiral and dwarf irregular galaxies are reviewed. The origin and structure of the generally exponential profiles in stellar disks is considered to result from…
The Galaxy's stellar populations are naturally classified into six `types', of which five have been observed. These are the thin disk (Pop I in the historical scheme), a discrete thick disk (Pop I.5), the metal-rich bulge, which was not…
We present first results of a program to study the dynamics of undisturbed bulgeless, low surface density disk galaxies in order to probe the underlying structure of dark matter halos. High resolution H-alpha rotation curves are combined…
I show that interstellar films of material thinner than a micron, drift away from the Galactic plane as a result of stellar radiation pressure. Such films, whether produced naturally by dust coagulation in proto-planetary disks or…
There is now ample evidence that the interstellar thick disks of spiral galaxies are dusty. Although the majority of extraplanar gas in the first few kiloparsecs above the plane of a spiral galaxy is matter that has been expelled from the…
We present mass models of a sample of 19 low surface brightness (LSB) galaxies and compare the properties of their constituent mass components with those of a sample of high surface brightness (HSB) galaxies.We find that LSB galaxies are…
High resolution N-body simulations show that the density profiles of dark matter halos formed in the standard CDM cosmogony can be fit accurately by scaling a simple ``universal'' profile. Regardless of their mass, halos are nearly…
We present new models for the formation of disk galaxies that improve upon previous models by following the detailed accretion and cooling of the baryonic mass, and by using realistic distributions of specific angular momentum. Under the…
One the most cited papers in astronomy is Ken Freeman's 1970 paper on exponential disks in galaxies. In this contribution I review what has been done in this area since then and what we can infer about systematic properties of disks in…
Based on N-body simulations, we show that realistic galactic disks are subject to bending instabilities of fire-hose type when the disks are substantially self-gravitating, that is, if they contain dark matter distributed in the disk.…
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…
The stellar disk in a spiral galaxy is believed to be truncated physically because the disk surface brightness is observed to fall faster than that for an exponential in the outer, faint regions. We review the literature associated with…
Our aim is to explore the relation between gas, atomic and molecular, and dust in spiral galaxies. Gas surface densities are from atomic hydrogen and CO line emission maps. To estimate the dust content, we use the disk opacity as inferred…
Galaxies are composed of baryonic stars and gas embedded in dark matter halos. Here I briefly review two aspects of the connection between baryons and their halos. (1) The observed baryon content of galaxies falls short of the cosmic baryon…