ar X iv : a st ro - p h / 96 05 04 2 v 1 9 M ay 1 99 6 Equilibria of flat and round galactic disks

ar X iv : a st ro - p h / 99 05 37 6 v 1 2 8 M ay 1 99 9 A 6 . 4 - hr positive superhump period in TV

ar X iv : a st ro - p h / 94 05 04 9 v 1 2 4 M ay 1 99 3 COMPLETE NORMALITY CONDITIONS FOR THE DYNAMICAL SYSTEMS ON RIEMANNIAN MANIFOLDS

New additional equations for the Newtonian dynamical systems on Riemannian manifolds are found. They supplement the previously found weak normality conditions up to the complete normality conditions for Newtonian dynamical systems.

ar X iv : a st ro - p h / 99 05 15 0 v 1 1 2 M ay 1 99 9 When SN explode in a starburst : trasitions among AGN types

Among the Active Galactic Nuclei (AGN) that have suffered type mutations, the classically classified Seyfert 2 NGC 7582 recently found at a Seyfert 1 stage, is perhaps one of the most puzzling cases, since it defies a well supported case for unification. We investigate the possibility that this type transition, common to other 12 AGN, is driven by supernovae (SN) exploding in a nuclear/circumnu...

ar X iv : a st ro - p h / 04 05 53 6 v 1 2 7 M ay 2 00 4 To appear in ApJ 9 / 04 A Minimum - Mass Extrasolar Nebula

By analogy with the minimum-mass solar nebula, we construct a surfacedensity profile using the orbits of the 26 precise-Doppler planets found in multiple-planet systems: Σ = 2200 g cm (a/1 AU), where a is the circumstellar radius and β = 2.0 ± 0.5. The minimum-mass solar nebula (β = 1.5) is consistent with this model, but the uniform-α accretion disk model (β ≈ 1) is not. In a nebula with β > 2...

ar X iv : a st ro - p h / 93 05 00 2 v 1 6 M ay 1 99 3 Visibility of Gravitational Lenses and the Cosmological Constant Problem

Recent observations suggest appreciable star formation activity in early-type galaxies down to redshift z ∼ 0.5. If so, there is likely to be dust in these galaxies. We consider the possibility that obscuration by dust can reconcile the observed frequency of gravitational lensing of quasar images with the considerably larger rate predicted in a low density cosmologically flat universe dominated...