Showing results 1 to 20 of 47
  COSMOGRAIL: Measuring Time Delays of Gravitationally Lensed Quasars to Constrain Cosmology; ; et al in The Messenger (2012) COSMOGRAIL is a long-term programme for the photometric monitoring of gravitationally lensed quasars. It makes use of several medium-size telescopes to derive long and well-sampled light curves of lensed ... [more ▼] COSMOGRAIL is a long-term programme for the photometric monitoring of gravitationally lensed quasars. It makes use of several medium-size telescopes to derive long and well-sampled light curves of lensed quasars, in order to measure the time delays between the quasar images. These delays directly relate to the Hubble constant H0, without any need for secondary distance calibrations. COSMOGRAIL was initiated in 2004, and has now secured almost a decade of data, resulting in cosmological constraints that are very complementary to other cosmological probes. [less ▲] Detailed reference viewed: 22 (3 ULg) TRAPPIST: TRAnsiting Planets and PlanetesImals Small TelescopeJehin, Emmanuel  ; Gillon, Michaël ; et alin The Messenger (2011), 145 TRAPPIST is a 60-cm robotic telescope that was installed in April 2010 at the ESO La Silla Observatory. The project is led by the Astrophysics and Image Processing group (AIP) at the Department of ... [more ▼] TRAPPIST is a 60-cm robotic telescope that was installed in April 2010 at the ESO La Silla Observatory. The project is led by the Astrophysics and Image Processing group (AIP) at the Department of Astrophysics, Geophysics and Oceanography (AGO) of the University of Liège, in close collaboration with the Geneva Observatory, and has been funded by the Belgian Fund for Scientific Research (F.R.S.-FNRS) and the Swiss National Science Foundation (SNF). It is devoted to the detection and characterisation of exoplanets and to the study of comets and other small bodies in the Solar System. We describe here the goals of the project and the hardware and present some results obtained during the first six months of operation. [less ▲] Detailed reference viewed: 17 (6 ULg)Studying the Magnetic Properties of Upper Main-sequence Stars with FORS1; ; Briquet, Maryline et alin The Messenger (2009), 135 We summarise the results of our recent magnetic field studies in upper main-sequence stars, which have exploited the spectropolarimetric capability of FORS1 at the VLT extensively. Detailed reference viewed: 12 (1 ULg)Behind the Scenes of the Discovery of Two Extrasolar Planets: ESO Large Programme 666; ; et al in The Messenger (2008), 133 This is the story of the Large Programme 666, dedicated to discover sub-stellar objects (extrasolar planets and brown dwarfs), and to measure their masses, radii, and mean densities. We hunt selected OGLE ... [more ▼] This is the story of the Large Programme 666, dedicated to discover sub-stellar objects (extrasolar planets and brown dwarfs), and to measure their masses, radii, and mean densities. We hunt selected OGLE transit candidates using spectroscopy and photometry in the ‘twilight zone’, stretching the limits of what is nowadays possible with the VLT. [less ▲] Detailed reference viewed: 8 (3 ULg)Circular Polarimetry Now Offered at EFOSC2; ; et al in The Messenger (2007), 129 Starting from period P79, circular polarimetry measurements can be carried out with EFOSC2 at the ESO 3.6-m telescope. Here we describe the motivations behind the upgrade of the instrument, and a few ... [more ▼] Starting from period P79, circular polarimetry measurements can be carried out with EFOSC2 at the ESO 3.6-m telescope. Here we describe the motivations behind the upgrade of the instrument, and a few results from the commissioning runs are used to show the excellent performance of the new polarimetry unit. [less ▲] Detailed reference viewed: 13 (2 ULg)Towards Precision Photometry with FORS: A Status Report; ; et al in The Messenger (2007), 128 The two FOcal Reducer and low-dis-persion Spectrographs (FORS) are the primary imaging instruments for the VLT. Because they are not direct imaging instruments, the accuracy of photometry which can ... [more ▼] The two FOcal Reducer and low-dis-persion Spectrographs (FORS) are the primary imaging instruments for the VLT. Because they are not direct imaging instruments, the accuracy of photometry which can routinely be obtained is limited by significant sky concentration and other effects. This article reports on the progress of a long-term project to improve the photometric calibration of the FORS instruments. [less ▲] Detailed reference viewed: 4 (0 ULg)FORS1 is getting Blue: New Blue Optimised Detectors and High Throughput Filters; ; et al in The Messenger (2007), 128 Ground-based observations in the ultraviolet part of the electromagnetic spectrum are notoriously difficult owing to absorption of the atmosphere, of optical elements and the poorer efficiency of ... [more ▼] Ground-based observations in the ultraviolet part of the electromagnetic spectrum are notoriously difficult owing to absorption of the atmosphere, of optical elements and the poorer efficiency of detectors. Now that CCD detectors with excellent UV response and cosmetic quality have become available, it was time to optimise FORS1 for imaging, low-resolution spectroscopic and polarimetric observations in the blue-UV. As a bonus, a new set of broadband filters with very high trans-mission and carefully defined filter bands were installed. [less ▲] Detailed reference viewed: 2 (0 ULg)The Host Galaxies of the Brightest Quasars: Gas-Rich Galaxies, Mergers, and Young Stars; Letawe, Géraldine ; et alin The Messenger (2006), 124 Because they are faint and hidden in the glare of a much brighter unresolved source, quasar host galaxies still challenge the most powerful telescopes, instrumentation and processing techniques ... [more ▼] Because they are faint and hidden in the glare of a much brighter unresolved source, quasar host galaxies still challenge the most powerful telescopes, instrumentation and processing techniques. Determining their basic morphological parameters and their integrated colours is feasible, but difficult, from imaging alone. However, detailed information on their stellar and gas contents and on their dynamics is achievable with deep spectroscopy. [less ▲] Detailed reference viewed: 19 (2 ULg)Deep Impact at ESO Telescopes; ; et al in The Messenger (2005), 121 This article is a first summary of the observations done with ESO telescopes and instrumentation in the context of NASA's Deep Impact (DI) space mission. The ESO observers were part of an extremely active ... [more ▼] This article is a first summary of the observations done with ESO telescopes and instrumentation in the context of NASA's Deep Impact (DI) space mission. The ESO observers were part of an extremely active, communicative and thus successful worldwide network of observers. Through this network all information was freely exchanged and highlights are reported here as well. [less ▲] Detailed reference viewed: 12 (2 ULg)The UVES Paranal Observatory Project: A Library of High- Resolution Spectra of Stars across the Hertzsprung-Russell Diagram; Jehin, Emmanuel ; et alin The Messenger (2003), 114 We present the UVES Paranal Observatory Project, consisting of acquisition, reduction, and public release of high-resolution, large wavelength coverage, and high signal-to-noise ratio stellar spectra ... [more ▼] We present the UVES Paranal Observatory Project, consisting of acquisition, reduction, and public release of high-resolution, large wavelength coverage, and high signal-to-noise ratio stellar spectra obtained with the UVES instrument of the ESO Very Large Telescope. Data for about 400 stars across the Hertzsprung-Russell diagram have been taken and reduced by members of the Paranal Science Operations Team and made publicly available through a WEB interface at www.eso.org/uvespop. [less ▲] Detailed reference viewed: 36 (0 ULg)Spectroscopy of quasar host galaxies at the VLT: stellar populations and dynamics down to the central kiloparsec; Letawe, Géraldine ; Magain, Pierre et alin The Messenger (2002), 107 not available Detailed reference viewed: 15 (1 ULg)The XMM Large Scale Structure Survey and its multi-lambda follow-up; ; et al Article for general public (2001) We present a unique European project which aims at mapping the matter distribution in the distant universe from hundreds of megaparsecs to galaxy scales. This comprehensive scientific approach constitutes ... [more ▼] We present a unique European project which aims at mapping the matter distribution in the distant universe from hundreds of megaparsecs to galaxy scales. This comprehensive scientific approach constitutes a new step in the synergy between space- and ground-based observatory resources and therefore a building block of the forthcoming Virtual Observatory. [less ▲] Detailed reference viewed: 10 (2 ULg)Achieving 1% photometric accuracy with the ESO Wide Field ImagerManfroid, Jean ; ; in The Messenger (2001), 104 The highly successful Wide Field Imager on the ESO/MPG 2.2-m telescope offers the possibility of undertaking photometry over a half-degree field. The authors discuss findings concerning the photometric ... [more ▼] The highly successful Wide Field Imager on the ESO/MPG 2.2-m telescope offers the possibility of undertaking photometry over a half-degree field. The authors discuss findings concerning the photometric performance of the camera. They describe strategies for dealing with the flat-field calibration error, which is often underestimated by observers. [less ▲] Detailed reference viewed: 4 (0 ULg)Lensed quasars: a matter of resolution; ; et al in The Messenger (2000), 101 Not Available Detailed reference viewed: 11 (5 ULg)Deconvolving spectra of lensing galaxies, QSO hosts, and more ...; Magain, Pierre ; Sohy, Sandrine et alin The Messenger (1999), 97 Not Available Detailed reference viewed: 1 (0 ULg)Erratum : A procedure for deriving accurate linear polarimetric measurements; Hutsemekers, Damien in The Messenger (1999), 97 Not Available Detailed reference viewed: 1 (0 ULg)A procedure for deriving accurate linear polarimetric measurements.; Hutsemekers, Damien in The Messenger (1999), 96 The authors present here a procedure written within the ESO MIDAS reduction package with the aim of deriving semi-automatically linear polarisation data from CCD images obtained with beam-splitters such ... [more ▼] The authors present here a procedure written within the ESO MIDAS reduction package with the aim of deriving semi-automatically linear polarisation data from CCD images obtained with beam-splitters such as those available at the ESO 3.6-m telescope equipped with EFOSC2 or at the VLT equipped with FORS1. The method is adequate for point-like objects and was used for measuring quasar polarisation. [less ▲] Detailed reference viewed: 12 (0 ULg)RX J0911.4+0551: a complex quadruply imaged gravitationally lensed QSO.; ; et al in The Messenger (1998), 92 The authors present their first observations of RX J0911.4+0551 at the 2.2-m ESO/MPI IRAC 2b in K-band which made them suspect that the QSO might be quadruple. This was confirmed on the optical data from ... [more ▼] The authors present their first observations of RX J0911.4+0551 at the 2.2-m ESO/MPI IRAC 2b in K-band which made them suspect that the QSO might be quadruple. This was confirmed on the optical data from the 2.56-m Nordic Optical Telescope, and on the NTT/SOFI data of the object. Careful deconvolution of the data allows to clearly resolve the object into four QSO components and a lensing galaxy. [less ▲] Detailed reference viewed: 13 (0 ULg)Deconvolution with correct sampling.Magain, Pierre ; ; Sohy, Sandrine in The Messenger (1997), 88 The authors briefly describe the basic ideas behind a new deconvolution technique which overcomes some of the drawbacks of the traditional methods and which gives results of high photometric and ... [more ▼] The authors briefly describe the basic ideas behind a new deconvolution technique which overcomes some of the drawbacks of the traditional methods and which gives results of high photometric and astrometric accuracy. The authors also show how it can be combined with other techniques (e.g. adaptive optics) to give even better results. [less ▲] Detailed reference viewed: 5 (0 ULg)PKS 1610-771: a highly reddened quasar?; Hutsemekers, Damien ; et alin The Messenger (1996), 85 Not Available Detailed reference viewed: 3 (0 ULg) |
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