High-resolution optical spectra of the ultra-luminous X-ray source (ULX) NGC 5408 X-1 show a broad component with a width of ~750 km s-1 in the He II and Hβ...

have complex and highly structured profiles. We discuss, in the context of the discrete cloud model of the broad-line region, three possible mechanisms by which...

Both the broad iron (Fe) line and the frequency of the kilohertz quasi-periodic oscillations (kHz QPOs) in neutron star low-mass X-ray binaries (LMXBs) can...

We analysed the X-ray spectra of six observations, simultaneously taken with XMM-Newton and Rossi X-ray Timing Explorer (RXTE), of the neutron-star low-mass X...

High-resolution spectroscopic observations have been obtained for the Wolf-Rayet galaxies He 2-10, II Zw 40, POX 4, and Tol 35. Several subregions have been...

During the 2008 September-October outburst of the accreting millisecond pulsar SAX J1808.4-3658, the source was observed by both Suzaku and XMM-Newton...

PKS 0537-441, a bright gamma -ray emitting blazar, was observed at radio, optical, UV and X-ray frequencies during various EGRET pointings, often quasi...

We present the results of a three-year campaign of broad-band photometry in the near-infrared J, H, K and L' bands for a sample of approximately 250 giant stars...

MAXI J1659-152 was discovered on 2010 September 25 as a new X-ray transient, initially identified as a gamma-ray burst, but was later shown to be a new X-ray...