Principal velocity surfaces in stellar dynamics

Stellar velocity dispersion in NLS 1 galaxies ⋆

Several authors recently explored the Black-Hole mass (MBH) vs. stellar velocity dispersion (σ∗) relationship for Narrow Line Seyfert 1 galaxies (NLS1s). Their results are more or less in agreement and seem to indicate that NLS1s fill the region below the fit obtained by Tremaine et al. (2002), showing a range of σ∗ similar to that of Seyfert 1 galaxies, and a lower MBH . Until now the [O iii] ...

Measuring Stellar Velocity Dispersions in Active Galaxies

We present stellar velocity dispersion (σ∗) measurements for a significant sample of 40 broad-line (Type 1) active galaxies for use in testing the well-known relation between black hole mass and stellar velocity dispersion. The objects are selected to contain Ca II triplet, Mg Ib triplet, and Ca H+K stellar absorption features in their optical spectra so that we may use them to perform extensiv...

Stellar Velocity Distribution in Galactic Disks

We present numerical studies of the properties of the stellar velocity distribution in galactic disks which have developed a saturated, two-armed spiral structure. In previous papers we used the Boltzmann moment equations (BME) up to second order for our studies of the velocity structure in self-gravitating stellar disks. A key assumption of our BME approach is the zero-heat flux approximation,...

Principal Curvatures of Surfaces

Stellar Dynamics of Dense Stellar Systems

Stellar dynamics is almost unreasonably well suited for an implementation in terms of special-purpose hardware. Unlike the case of molecular dynamics, stellar dynamics deals exclusively with a long-range force, gravity, which leads to a computational cost scaling as the square of the number of stars involved. While special tricks can lead to a reduction of this cost from ∼ N2 to ∼ N logN in the...