(ii) Dwarf spheroidals possess dark matter haloes of about 10 kpc radius around them, and have an ( M/L ) ratio of about 10 4 . (iii) The haloes of spiral galaxies ( e.g. Milky Way) extend to about 100 kpc in radius. If 'cold' dark matter makes up the haloes, then no ...
A Plummer 3-dimensional density profile with the Plummer radius r0 is given by ρ=ρ0(1+rr0)−α. Functions of this form are often used as models to describe the density profile of dense stellar clusters. For black holes the spin can be characterized via the angular momentum parameter a...
The disk of stars in the Milky Way does not have a sharp edge beyond which there are no stars. Rather, the concentration of stars drops smoothly with distance from the center of the Galaxy. Beyond a radius of roughly 69, the number of stars per cubic parsec drops much faster with radius...
The Milky Way’s ‘plane of satellites’ canonically consists of the 11 ‘classical’ satellites, the brightest within a radius ofr = 300 kpc of the Galactic Centre, believed to constitute a complete sample. To characterize the spatial anisotropy of a system ofNsatellites, it is customary...
Here, we work out how to determine the stellar surface-mass density contributions at the solar radius R_0 of each such sub-population, accounting for the survey selection function, and for the fraction of the stellar population mass that is reflected in the spectroscopic target stars given ...
The LON is not stable at any given radius, but it twists. The twisted pattern suggests that the formation of the Milky Way's warp is dominated by the massive inner disk. The kinematic warp defined by the Cepheids is also in concordance with the spatial warp. In the 2020 era, the ...
By “seeing” how the disk warp evolves with age, the researchers found that the warp precesses in a retrograde direction at a rate of 2 km/s/kpc (or 0.12 degrees per million years). Further measurements showed that the warp’s precession rate gradually decreases with radius. Regardless of...
We find that a break radius is strongly related to the build up of stars at apocentres. We relate these findings to observations, and find that the `break' in the Milky Way density profile is likely associated with a relatively early (~ 6-9 Gyr ago) and massive accretion event. In ...
The lower dashed curve assumes structural parameters similar to that of Draco, with a King core radius of 0.18 kpc and a King limiting radius of 0.93 kpc [35]. Each curve assumes that the measurement uncertainty on each star is 2 km s−1. In both cases, the stars have been...
This stellar system has an extended spatial distribution with a half-light radius of 38 +12/-11 pc, which clearly distinguishes it from a globular cluster with comparable luminosity. Thus, Virgo I is one of the faintest dwarf satellites known and is located beyond the reach of the Sloan ...