IGR J16479−4514 is a Supergiant Fast X–ray Transient (SFXT), a new class of High Mass X–ray Binaries, whose number is rapidly growing thanks to the INTEGRAL observations of the Galactic plane. It was regularly monitored with Swift/XRT since November 2007, to study the quiescent emission, the outburst properties and their recurrence. A new bright outburst, reaching fluxes above 10 −9 erg cm −2 s...

We report on archival observations of the ultra-soft X-ray transient 4U 1630−47. the region of sky containing 4U 1630−47 and a faint source was detected. While it is possible that this emission originates from another object within the LAC field of view, its properties are consistent with an observation towards the end of an outburst. The times of the Ginga outbursts are consistent with the kno...

Following the recent outburst of the recurrent nova RS Oph on 2006 Feb 12, we measured its nearinfrared size using the IOTA, Keck, and PTI Interferometers at multiple epochs. The characteristic size of ∼3 milliarcseconds hardly changed over the first 60 days of the outburst, ruling out currentlypopular models whereby the near-infrared emission arises from hot gas in the expanding shock. The emi...

Using the black hole transient X-ray source A0620-00 as an example we study the physical interplay of three theoretical constituents for modelling these transient sources: (1) the advection-dominated accretion flow (ADAF) onto the central black hole, (2) the evaporation of matter from the cool outer disk forming a coronal flow and (3) standard disk evolution leading to outburst cycles by accret...