Antonio Lanza

parsec evolutionary tracks of massive stars up to 350 M⊙ at metallicities 0.0001 ≤ Z ≤ 0.04

We complement the PARSEC data base of stellar evolutionary tracks with new models of massive stars, from the pre-main sequence phase to the central carbon ignition. We consider a broad range of metallicities, 0.0001

Self-gravitating thin disks around rapidly rotating black holes

\leq Z \leq

Curving Newtonian Space

0.04 and initial masses up to

General Relativistic Structure of Star-Toroid Systems

M_{\rm ini}=350\,M_\odot

The Renaissance of general relativity and cosmology : a survey to celebrate the 65th birthday of Dennis Sciama

. The main difference with respect to our previous models of massive stars is the adoption of a recent formalism accounting for the mass-loss enhancement when the ratio of the stellar to the Eddington luminosity,

Baroclinic toroidal figures of equilibrium

\Gamma_e

PERIODIC X-RAY VARIABILITY OF THE SEYFERT GALAXY NGC 6814

, approaches unity. With this new formalism, the models are able to reproduce the Humphreys-Davidson limit observed in the Galactic and Large Magellanic Cloud colour-magnitude diagrams, without an ad hoc mass-loss enhancement. We also follow the predictions of recent wind models indicating that the metallicity dependence of the mass-loss rates becomes shallower when

The Renaissance of General Relativity and Cosmology: Author Addresses

\Gamma_e

The Renaissance of General Relativity and Cosmology: Frontmatter

approaches unity. We thus find that the more massive stars may suffer from substantial mass-loss even at low metallicity. We also predict that the Humphreys-Davidson limit should become brighter at decreasing metallicity. We supplement the evolutionary tracks with new tables of theoretical bolometric corrections, useful to compare tracks and isochrones with the observations. For this purpose, we homogenize existing stellar atmosphere libraries of hot and cool stars (PoWR, ATLAS9 and Phoenix) and we add, where needed, new atmosphere models computed with WM-basic. The mass, age and metallicity grids are fully adequate to perform detailed investigations of the properties of very young stellar systems, both in local and distant galaxies. The new tracks supersede the previous old Padova models of massive stars.

Nonlinear superposition of solutions to self-gravitating fluid equations

Sequences of equilibrium numerical models have been constructed for self-gravitating thin disks encircling rapidly rotating black holes. The multigrid method was used for solving numerically the stationary, axisymmetric Einstein equations. The black hole is described either by specifying its angular velocity and the coordinate radius of the horizon or, alternatively, by specifying the area of the horizon and the angular momentum