Persberichten

27 mei 1999: An important event took place at the ESO Paranal Observatory last week. Following intense work over several months, the big pieces of the mechanical structure of the fourth 8.2-m VLT Unit Telescope have been assembled! On May 19, at 10:00 in the morning, the VLT UT4 (YEPUN) top ring with the spider that carries the M2 Unit on which the 1.1-m secondary mirror will later be placed, was installed on the top of the telescope. This is the last big mechanical piece of the last UT telescope on Paranal. Two photos (PR 23a/99 and 23b/99) illustrate this. There are now two operating 8.2-m telescopes (ANTU/UT1 and KUEYEN/UT2) and two telescope structures (MELIPAL/UT3 and YEPUN/UT4). The latter telescopes will see First Light within the next year. The large 300 tonnes crane with which the heavy telescope pieces were lifted into place and which has dominated the skyline of the Paranal mountaintop for nearly 3 years, will now be dismantled and shipped elsewhere.

18 mei 1999: International teams of astronomers are now busy working on new and exciting data obtained during the last week with telescopes at the European Southern Observatory (ESO). Their object of study is the remnant of a mysterious cosmic explosion far out in space, first detected as a gigantic outburst of gamma rays on May 10. Gamma-Ray Bursters (GRBs) are brief flashes of very energetic radiation - they represent by far the most powerful type of explosion known in the Universe and their afterglow in optical light can be 10 million times brighter than the brightest supernovae [1]. The May 10 event ranks among the brightest one hundred of the over 2500 GRB's detected in the last decade.

30 april 1999: The new Wide-Field Imager (WFI) at the MPG/ESO 2.2-m telescope at the La Silla observatory continues to obtain impressive images of the southern sky. Recently, a series of images were obtained of areas in the Milky Way band, including some in which interstellar nebulae of gas and dust are seen. Each frame records 8184 x 8196, or over 67 million, pixels in a sky field of 32 x 32 arcmin 2. The present photos show the RCW 108 complex of bright and dark nebulae in the southern association Ara OB1, a star-forming region in the constellation Ara (The Altar), deep in the southern sky.

30 april 1999: During the continued tests of the two astronomical instruments (FORS1 and ISAAC) at the first VLT 8.2-m Unit Telescope, ANTU (formerly UT1), impressive images have been obtained of a variety of celestial objects. These observations were made through different optical filtres. In some cases, CCD frames could be combined into colour renderings of the objects. We show here some of the new images, obtained with the multi-mode FORS1 instrument shortly before the arrival of the first "visiting astronomers" at Paranal in early April 1999. The first (20a/99) is of a small and nearby, dark cloud, a type of object that has not been imaged before by the VLT, and among the galaxies, the warped dust band in a "Sombrero"-like galaxy is of particular scientific interest. In most cases, the image quality is of the order of 0.6 arcsec.

7 april 1999: The VLT Control Room at the Paranal Observatory is becoming a busy place indeed. From here, two specialist teams of ESO astronomers and engineers now operate two VLT 8.2-m Unit Telescopes in parallel, ANTU and KUEYEN (formerly UT1 and UT2). Regular science observations have just started with the first of these giant telescopes, while impressive astronomical images are being obtained with the second.

26 maart 1999: The portrait of NGC 4945 above adorns the centrefold of the most recent issue of the ESO Messenger (no. 95; March 1999). It provides another impressive demonstration of the observational capabilities of the new WFI Camera at the MPG/ESO 2.2-m telescope at La Silla.

6 maart 1999: This has been a busy, but also a very successful and rewarding week for the European Southern Observatory and its staff. While "First Light" was achieved at the second 8.2-m VLT Unit Telescope (UT2) ahead of schedule, UT1 produced its sharpest image so far. This happened at a moment of exceptional observing conditions in the night between March 4 and 5, 1999. During a 6-min exposure of the majestic spiral galaxy, NGC 2997, stellar images of only 0.25 arcsec FWHM (full-width half-maximum) were recorded. This and two other frames of nearly the same quality have provided the base for the beautiful colour-composite shown above. At this excellent angular resolution, individual star forming regions are well visible along the spiral arms. Of particular interest is the peculiar, twisted shape of the long spiral arm to the right.

27 februari 1999: To mark the beginning of the VLT era, the European Southern Observatory is organizing a VLT Opening Symposium which will take place in Antofagasta (Chile) on 1-4 March 1999, just before the start of regular observations with the ESO Very Large Telescope on 1 April, 1999. The Symposium occupies four full days and is held on the campus of the Universidad Catolica del Norte. It consists of plenary sessions on "Science in the VLT Era and Beyond" and three parallel Workshops on "Clusters of Galaxies at High Redshift" , "Star-way to the Universe" and "From Extrasolar Planets to Brown Dwarfs".

27 februari 1999: The galaxy cluster 1ES 0657-55 is located in the southern constellation Carina (The Keel), south of the Milky Way band. Its redshift has been measured as z = 0.29. It is a source of strong and very hot X-ray emission and has an asymmetric galaxy distribution, indicating a large mass and recent formation. Images obtained with the ESO 3.6-m New Technology Telescope (NTT) at La Silla have revealed the presence of an arc , i.e. presumably a background galaxy at larger distance, whose image is strongly distorted by the gravitational field of this cluster.

27 februari 1999: NGC 1850 is a double cluster in the Large Magellanic Cloud, a satellite galaxy to the Milky Way Galaxy, deep in the southern sky. This cluster is representative of a class of objects, young, globular-like stellar associations, that has no counterpart in our own Galaxy.

27 februari 1999: The FORS1 multi-mode instrument is able to record images as well as spectra of even very distant objects. During the past months, data have been obtained that show the properties of some of the remotest known objects in the Universe.

27 februari 1999: NGC 1232 is a prominent southern Sc spiral galaxy in the constellation Eridanus (The River). With a diameter of nearly 200,000 lightyears, it is about twice the size of the Milky Way galaxy. The distance is about 100 million light-years, but the excellent optical quality of the VLT and FORS allows us to see an incredible wealth of details.

27 februari 1999: Continuing progress in astronomical technology is opening new possibilities for the study of the distant universe. One of the most exciting, recent additions to this branch of astrophysics, known as cosmology, has been the discovery of a large population of galaxies in the primordial Universe in which intensive star-formation is going on. They are so distant (their redshifts are larger than 3 [1]) that the corresponding look-back time is over 90% of the age of the Universe, now estimated at about 14 - 15 billion years (1 billion = 1,000 million). We observe these objects as they were, when the Universe was between 1 and 2 billion years old. The investigation of the early Universe is one of the primary scientific goals that have motivated the construction of the ESO Very Large Telescope and its very diverse complement of instrumentation. The aim of these studies is to extend the observations of basic properties of galaxies to objects at the largest possible distances and hence the earliest possible epochs. We would like to learn as much as possible about these very faint galaxies, including their numbers and hence their space density, as well as their brightness, colours, sizes and shapes. What are the rates with which stars are formed in different galaxies at different epochs, what is their chemical composition and mass? How do they move in space and how do they cluster?

27 februari 1999: Various observations were made with ISAAC at the Nasmyth focus of VLT UT1 during the recent commissioning periods for this infrared multi-mode instrument. Some of the first results from the VLT Infrared Spectrometer And Array Camera (ISAAC) were published earlier. The following photos illustrate the type of front-line work that is now possible with ISAAC. The possibility to obtain high-quality infrared spectra of even quite faint (and remote) objects is particularly interesting.

27 februari 1999: The VLT UT1 and FORS1 has performed observations of many different types of objects during the past months. While much effort has been spent on extremely distant galaxies, some exposures were also made on more nearby systems, including some dwarf galaxies in the Local Group of Galaxies. The Andromeda Galaxy and the Magellanic Clouds, as well as our own Milky Way Galaxy, are the best known members of this group.

27 februari 1999: Studies of "Deep Fields" are becoming common practice in astronomy. To mention a few: the two Hubble Deep Fields ( HDF-N and HDF-S , north and south of the celestial equator), the NTT Deep Field, the AXAF Deep Field , the FORS Deep Field. The latter will be observed during FORS1 "guaranteed time" that is available to astronomers from those institutes that built this instrument. All of these sky fields have been selected for being quite 'empty', in the sense that few brighter objects are seen in them. They are thus of the same type ('generic'), with the partial exception of HDF-S that contains a QSO (quasar).

27 februari 1999: NGC 1365 is one of the most prominent "barred" galaxies in the sky. It is a supergiant galaxy with a diameter of about 200,000 lightyears, seen in the direction of the southern constellation Fornax (The Furnace). It is a major member of the Fornax Cluster of Galaxies . The distance is about 60 million light-years and the recession velocity has been measured as 1632 km/sec.

25 februari 1999: While much attention is now directed towards the VLT Opening Symposium that will take place in Antofagasta on 1-4 March 1999, assembly work on the VLT Unit Telescopes proceeds at Paranal.

18 februari 1999: A group of ESO astronomers [1] has used new observations, obtained with the first 8.2-m VLT Unit Telescope (UT1) during the "Science Verification" programme, to show that a globular cluster in the Milky Way galaxy is "evaporating" and has already lost its faintest stars.

16 februari 1999: A new, short videotape, ESO Video News Reel no. 4 - "VLT UT1 Soon Ready to Receive the Astronomers," is being issued in connection with the start, on April 1, 1999, of regular observations with the VLT UT1 and the associated events in Chile. These include the VLT Opening Symposium in Antofagasta (March 1-4, 1999) and the official VLT Inauguration Ceremony at Paranal (March 5, 1999).