Table of Contents Messenger No. 137 (September 2009)
Astronomy in Austria
Austria officially became the fourteenth ESO member in June 2009. A brief outline of the recent developments and scientific highlights of astronomical research in Austria is presented. Having started from a relatively low level a few years ago, astronomical research is now expanding very rapidly thanks to the accession to ESO.
Telescopes and Instrumentation
Direct Imaging of Exoplanets and Brown Dwarfs with the VLT: NACO Pupil-stabilised Lyot Coronagraphy at 4 µm
NACO is the versatile adaptive optics assisted near-infrared instrument at the VLT. Among its many modes it offers spectral differential imaging that efficiently enhances the contrast in searches for faint companions. Recently, an additional method to calibrate quasi-static speckles through angular differential imaging has been developed, offering the option to operate NACO in a pupil-tracking mode. Using this new mode, in combination with Lyot coronagraphy and an optimal choice of observing wavelength in the thermal infrared around 4 µm, allows NACO to reach unprecedented sensitivities for masses of companions for all but the hottest exoplanets, beginning to open up the mass domain targeted by future instruments such as SPHERE.
The AstraLux Sur Lucky Imaging Instrument at the NTT
Lucky Imaging is an observational technique that aims to achieve nearly-diffraction-limited image quality from the ground on 2–4-metre-class telescopes. While diffraction-limited observations from the ground are usually accomplished with the help of adaptive optics in the near-infrared spectral range at almost all 8–10-metre-class telescopes, Lucky Imaging aims for a similar imaging performance at shorter wavelengths, in particular from 0.7–1.1 microns. AstraLux Sur, a visitor instrument for the NTT, built at the Max-Planck-Institute for Astronomy, is described and some early results are presented.
Halftoning for High-contrast Imaging: Developments for the SPHERE and EPICS Instruments
Controlling the amplitude of light is crucial for many scientific applications, such as in imaging systems, astronomical instruments or laser physics. We provide a brief overview of recent R&D activities at ESO using halftoning, the process of presenting a continuous image through use of dots. Customised filters with spatially varying transmission are produced using a binary array of metal pixels that offers excellent control of the local transmission. Applications to the production of an apodiser for the VLT SPHERE instrument and a mask for E-ELT EPICS are presented.
First Images from the VLT Interferometer
The ESO Very Large Telescope Interferometer has recently produced its first images, achieving a spatial resolution of a few milliarcseconds. The published images reveal the precise astrometry of close massive binaries (θ1 Ori C and HD87643), the presence of material close to the surface of an old, variable star (T Lep), and the dusty environment of an active galactic nucleus (NGC 1068). However, this is only a first step and additional results and numerous improvements are expected in the forthcoming years.
Constraining Quasar Structural Evolution with VLT/ISAAC
We describe a VLT–ISAAC spectroscopic survey of the Hb region for more than 50 quasars at redshifts between 1 and 3. We use the width of Hb as a virial estimator of black hole mass and the Eddington ratio. The minimum observed width of Hb increases from ~ 500–1000 km/s at low luminosity to ~ 3500 km/s in the high luminosity domain. This trend is consistent with the virial assumption and a broad line region size-luminosity relation with exponent a ~ 0.65. Broader lined sources show a second very broad and redshifted Hb line component, which should be removed for reliable black hole mass estimation.
Velocity Fields of Distant Galaxies with FORS2
We describe a method of obtaining two-dimensional velocity fields of distant, faint and small, emission-line galaxies efficiently with FORS2 at the VLT. The fields are examined for kinematic substructure to identify possible interaction processes. Numerical simulations of tidal interactions and ram pressure effects reveal distinct signatures observable with our method. We detect a significant fraction of galaxies with irregular velocity fields both in the field and cluster environments.
Wandering in the Redshift Desert
The cosmic star formation rate, active galactic nuclei activity, galaxy growth, mass assembly and morphological differentiation all culminate at redshift z ~ 2. Yet, the redshift interval 1.4 < z < 3 is harder to explore than both the closer and the more distant Universe. In spite of so much action taking place in this spacetime portion of the Universe, it has been dubbed the “redshift desert”, as if very little was happening within its boundaries. The difficulties encountered in properly mapping the galaxy populations inhabiting the desert are illustrated in this paper, along with some possible remedies.
Health, Safety and Performance in High Altitude Observatories: A Sustainable Approach
The research project “Optimising Performance, Health and Safety in High Altitude Observatories” was initiated by ESO to establish an approach to promote the well-being of staff working at its high altitude observatories, and in particular at the Antiplano de Chajnantor. A survey by a questionnaire given to both workers and visitors was employed to assess the effects of working conditions at high altitude. Earlier articles have outlined the project and reported early results. The final results and conclusions are presented, together with a concept for sustainable development to improve the performance, health and safety at high altitude employing Critical Incident Stress Management.
Report on the Workshop Impact of ALMA on Spanish Extragalactic Astronomy
In order to prepare the Spanish extragalactic community for the impact of ALMA science, a meeting with participation of non-radio astronomers was held to introduce the ALMA capabilities and to explore the synergies with optical and infrared facilities.
Report on the ESO Workshop E-ELT Design Reference Mission and Science Plan
ESO hosted a dedicated workshop on the European Extremely Large Telescope (E-ELT) Design Reference Mission (DRM) and the Design Reference Science Plan (DRSP). The main aim of this three-day workshop was to exchange information and ideas with the scientific community on the status of the E-ELT and in particular on the development of the E-ELT science case through simulations.
Report on the ESO Workshop Imaging at the E-ELT
The aim of this one-day workshop, part of the FP7-funded programme to prepare for the European Extremely Large Telescope, was to bring together members of the community working on wide-field imagers on 4–8-metre-class telescopes and on instruments and science cases related to imaging at the E-ELT, exploring complementarities and synergies between the two communities.
ESO at the XXVIIth IAU General Assembly
Report on the 2009 ESO Fellows Symposium
The fourth ESO Fellows Symposium took place in Garching from 8–10 June 2009. This year’s symposium brought together 28 ESO Fellows from Chile and Germany to meet their colleagues from across the ocean, discuss their research and provide feedback on ESO’s Fellowship programme. This year’s symposium also included training workshops to enhance the practical skills of ESO Fellows in today’s competitive job market.
Report on the 2009 Joint Observatories Science Retreat in Chile
In Chile, an old tradition has been revived with a new twist. Recently, more than 50 astronomers from ESO, ALMA, Gemini, CTIO, Las Campanas and SOAR participated in a two-day Joint Observatories Science Retreat that was held in La Serena. The goal of this event was to bring together astronomers from all the major international observatories in Chile to share their science, to discuss common interests and to stimulate new research collaborations.
News from the ESO Science Archive Facility
The latest developments from the archive are presented. Information is provided to the astronomical community on new data releases and services.
Fellows at ESO
Announcement of the ESO Workshop Galaxy Clusters in the Early Universe
Announcement of the ESO Workshop The Origin and Fate of the Sun: Evolution of Solar-mass Stars Observed with High Angular Resolution
ESO and EDP Sciences Sign New Contract for Astronomy and Astrophysics