The Space, Luminosity And Velocity Distribution Of Faint Stars

The Distribution of Nearby Stars in Velocity Space

From the tangential velocities of stars all over the sky, one can, in a statistical way, infer their 3D velocity distribution. An application to Hipparcos data reveals rich structure in the planar stellar motions: there are several moving groups, increasing in number with stellar type but decreasing in importance. A distinct group of outward moving stars with low rotation velocities might be as...

Redshift-space clustering of SDSS galaxies – luminosity dependence, halo occupation distribution, and velocity bias

We present the measurements and modelling of the small-to-intermediate scale (∼0.1– 25 h−1 Mpc) projected and three-dimensional redshift-space two-point correlation functions (2PCFs) of local galaxies in the Sloan Digital Sky Survey Data Release 7. We find a clear dependence of galaxy clustering on luminosity in both projected and redshift spaces, generally being stronger for more luminous samp...

The Distribution of Nearby Stars in Velocity Space Inferred from Hipparcos Data

The velocity distribution f(v) of nearby stars is estimated, via a maximum-likelihood algorithm, from the positions and tangential velocities of a kinematically unbiased sample of 14 369 stars observed by the HIPPARCOS satellite. f shows rich structure in the radial and azimuthal motions, vR and vφ, but not in the vertical velocity, vz: there are four prominent and many smaller maxima, many of ...

Note on the Difference in Velocity between Absolutely Bright and Faint Stars by J. H. Oort

Space and Velocity Distributions of Galactic Isolated Old Neutron Stars

I present the results of Monte Carlo orbital simulations of Galactic Neutron Stars (NSs). The simulations take into account the up-to-date observed NS space and velocity distributions at birth, and account for their formation rate. I simulate two populations of NSs. NSs in the first population were born in the Galactic disk at a constant rate, in the past 12 Gyr. Those in the second population ...