相关论文: Spiral Galaxies' Disk Dominance and Testing MOND

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…

We follow the evolution of disk galaxies within a cluster that forms hierarchically in a cold dark matter N-body simulation. At a redshift z=0.5 we select several dark matter halos that have quiet merger histories and are about to enter the…

Anemic galaxies have less prominent star formation than normal galaxies of the same Hubble type. Previous studies showed they are deficient in total atomic hydrogen but not in molecular hydrogen. Here we compare the combined surface…

Rotation curves constrain a galaxy's underlying mass density profile, under the assumption that the observed rotation produces a centripetal force that exactly balances the inward force of gravity. However, most rotation curves are measured…

Deep HI observations of the outer parts of disc galaxies demonstrate the frequent presence of extended, well-developed spiral arms far beyond the optical radius. To understand the nature and the origin of such outer spiral structure, we…

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 use a 380 h-1 pc resolution hydrodynamic AMR simulation of a cosmic filament to investigate the orientations of a sample of ~100 well-resolved galactic disks spanning two orders of magnitude in both stellar and halo mass. We find: (i) At…

We study the vertical density distribution of stars and gas (HI and H_2) in a galactic disk which is embedded in a dark matter halo. The new feature of this work is the inclusion of gas, and the gravitational coupling between stars and gas,…

Using imaging data from the SDSS survey, we present the g' and r' radial stellar light distribution of a complete sample of ~90 face-on to intermediate inclined, nearby, late-type (Sb-Sdm) spiral galaxies. The surface brightness profiles…

Analyses of halo shapes for disc galaxies are said to give incongruous results. I point out that the modified dynamics (MOND) predicts for disc galaxies a distribution of fictitious dark matter that comprises two components: a pure disc and…

Low Surface Brightness (LSB) galaxies are dominated by dark matter, and their rotation curves thus reflect their dark matter distribution. Recent high-resolution rotation curves suggest that their dark matter mass-density distributions are…

The outer regions of disk galaxies show a drop-off in optical and Halpha emission, suggesting a star formation threshold radius, assumed to owe to a critical surface density below which star formation does not take place. Signs of…

The density-wave theory of spiral structure proposes that star formation occurs in or near a spiral-shaped region of higher density that rotates rigidly within the galactic disk at a fixed pattern speed. In most interpretations of this…

We examine ultraviolet halos around a sample of highly inclined galaxies within 25 Mpc to measure their morphology and luminosity. Despite contamination from galactic light scattered into the wings of the point-spread function, we find that…

Disc dominated galaxies can be difficult to accommodate in a hierarchical formation scenario like $\Lambda$CDM, where mergers are an important growth mechanism. However, observational evidence indicates that these galaxies are common. We…

We present a relationship between spiral arm pitch angle (a measure of the tightness of spiral structure) and the mass of supermassive black holes (BHs) in the nuclei of disk galaxies. We argue that this relationship is expected through a…

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…

We analyse a sample of over 1000 stars from 32 fields imaged in the V and I bands with the Wide Field and Planetary Camera, on board of the Hubble Space Telescope. The fields are located at Galactic latitudes | b | >= 15deg and in various…

The mass distribution of the Galactic disk is constructed from the terminal velocity curve and the mass discrepancy-acceleration relation. Mass models numerically quantifying the detailed surface density profiles are tabulated. For $R_0 =…

The opacity of foreground spiral disks can be probed from the number of distant galaxies seen through them. To calibrate this number for effects other than the dust extinction, Gonzalez et al (1998) developed the "Synthetic Field Method". A…