This paper discusses the properties of the European Large Area ISO Survey (ELAIS) 15-μm quasars and tries to establish a robust method of quasar selection for future use within the Spitzer Wide-Area Infrared Extragalactic Survey (SWIRE) framework. The importance of good-quality ground-based optical data is stressed, both for the selection of

We present Very Large Telescope (VLT) UVES echelle spectrophotometry of the Orion nebula in the 3100-10400 Årange. We have measured the intensity of 555 emission lines, many of them corresponding to permitted lines of different heavy-element ions. This is the largest set of spectral emission lines ever obtained for a Galactic or extragalactic HII

We propose to observe the peculiar neutron star low mass X-ray binary (NS/LMXB) 2S 1803-245 in quiescence. Together with EXO 1745-248, it is the only transient that reached peak luminosities comparable to the Eddington- limit. This makes 2S 1803-245 one of the thermally brightest NSs in quiescence according to the cooling theory, and therefore one

The statistics of vertical structure of the turbulence affect the complexity of the design and implementation of Multi-Conjugate Adaptive Optics (MCAO) systems. The operation of these systems could be optimized if the stability of the layers were such as to permit to fix the deformable mirrors (DMs) at specific heights. Moreover, it is desirable to

The radial velocity technique is currently used to classify transiting objects. While capable of identifying grazing binary eclipses, this technique cannot reliably identify blends, a chance overlap of a faint background eclipsing binary with an ordinary foreground star. Blends generally have no observable radial velocity shifts, as the foreground

VLT J- to M'-band adaptive optics observations of the Circinus galaxy on parsec scales resolve a central bright Ks-band source with a FWHM size of 1.9+/-0.6 pc. This source is only visible at wavelengths longward of 1.6 μm and coincides in position with the peak of the [Si VII] 2.48 μm coronal line emission. With respect to the peak of the central