ar X iv : a st ro - p h / 99 05 11 9 v 1 1 1 M ay 1 99 9 A state transition of GX 339 - 4 observed with RXTE

ar X iv : a st ro - p h / 98 05 07 7 v 1 6 M ay 1 99 8 Long - Term X - ray Variability in GX 354 – 0

We report for the first time the detection of long-term X-ray variability in the bright bulge source GX 354–0 (=4U 1728–34) observed with the All Sky Monitor (ASM) on board the Rossi X-Ray Timing Explorer (RXTE). The 2-year RXTE ASM database reveals significant power at ∼ 72 days. Similar behaviour was seen in the 6-year Ariel 5 ASM database, but at a period of ∼ 63 days. The timescales and lig...

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 / 99 04 24 4 v 1 1 9 A pr 1 99 9 Is SGR 1900 + 14 a Magnetar ?

We present RXTE observations of the soft gamma–ray repeater SGR

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 / 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.