The VLTI has been operating for about 5 years using the VINCI instrument first, and later MIDI. In October 2005
(Period 76) the first Science Operations with the AMBER instrument started, with 14 Open Time proposals in
the observing queues submitted by the astronomical community. AMBER, the near-infrared/red focal instrument
of the VLTI, operates in the bands J, H, and, K (i.e. 1.0 to 2.5 micrometers) with three beams, thus enabling the
use of closure phase techniques. Light was fed from the 8m Unit Telescopes (UT). The Instrument was offered
with the Low Resolution Mode (JHK) and the Medium Resolution Mode in K-band on the UTs. We will present
how the AMBER VLTI Science Operations currently are performed and integrated into the general Paranal
Science Operations, using the extensive experience of Service Mode operations performed by the Paranal Science
operations and in particular applying the know-how learned from the two years of MIDI Science Operations. We
will also be presenting the operational statistics from these first ever Open Time observations with AMBER.
The ESO Very Large Telescope Interferometer (VLTI) is the first general-user interferometer that offers near- and mid-infrared long-baseline interferometric observations in service and visitor mode to the whole astronomical community. Over the last two years, the VLTI has moved into its regular science operation mode with the two science instruments, MIDI and AMBER, both on all four 8m Unit Telescopes and the first three 1.8m Auxiliary Telescopes. We are currently devoting up to half of the available time for science, the rest is used for characterization and improvement of the existing system, plus additional installations. Since the first fringes with the VLTI on a star were obtained on March 17, 2001, there have been five years of scientific observations, with the different instruments, different telescopes and baselines. These observations have led so far to more than 40 refereed publications. We describe the current status of the VLTI and give an outlook for its near future.
MIDI (MID-infrared Interferometric instrument) gave its first N-band (8 to 13 micron) stellar interference fringes on the VLTI (Very Large Telescope Interferometer) at Cerro Paranal Observatory (Chile) in December 2002. An lot of work had to be done to transform it, from a successful physics experiment, into a premium science instrument which is offered to the worldwide community of astronomers since September 2003. The process of "paranalization", carried out by the European Southern Observatory (ESO) in collaboration with the MIDI consortium, has aimed to make MIDI simpler to use, more reliable, and more efficient. We describe in this paper these different aspects of paranalization (detailing the improvement brought to the observation software) and the lessons we have learnt. Some general rules, for bringing an interferometric instrument into routine operation in an observatory, can be drawn from the experience with MIDI. We also report our experience of the first "service mode" run of an interferometer (VLTI + MIDI) that took place in April 2004.
The Very Large Telescope Interferometer (VLTI) on Cerro Paranal (2635 m) in Northern Chile reached a major milestone in September 2003 when the mid infrared instrument MIDI was offered for scientific observations to the community. This was only nine months after MIDI had recorded first fringes. In the meantime, the near infrared instrument AMBER saw first fringes in March 2004, and it is planned to offer AMBER in September 2004.
The large number of subsystems that have been installed in the last two years - amongst them adaptive optics for the 8-m Unit Telescopes (UT), the first 1.8-m Auxiliary Telescope (AT), the fringe tracker FINITO and three more Delay Lines for a total of six, only to name the major ones - will be described in this article. We will also discuss the next steps of the VLTI mainly concerned with the dual feed system PRIMA and we will give an outlook to possible future extensions.
The Very Large Telescope Interferometer (VLTI) makes in its final configuration use of four 1.8m Auxiliary Telescopes, which can be located on 30 different stations. These four telescopes can theoretically be arranged in more than 25,000 different configurations. Of course, operational constraints will allow only some dozens of these configurations to be realized over the entire lifetime of the interferometer. Furthermore, there are restrictions on sky accessibility posed by both physical limits of the delay lines and vignetting by the 8.2m telescope enclosures. We describe criteria for an optimum selection of configurations and propose a subset of AT stations to be offered for science operations with the VLTI.
The VLTI now has performed three years of science operations using the
VINCI instrument since the first fringes on a star were obtained on March 17, 2001. Since December 5th, 2001, shared risk science observations have been performed with VINCI. In April 2004 (period 73) we have started science operations with the MIDI instrument. Subsequently both the AMBER instrument and the Auxiliary Telescopes (ATs) will be also running under the science Operations at Paranal and offered to the astronomical community.
We will present how the VLTI Science operations currently are performed and integrated into the general Paranal Science Operations scheme, using the extensive experience of Service Mode operations performed by the Paranal Science operations group. We focus on the execution of the Service mode operations, how they are planned, performed, evaluated, and processed and the data finally sent to ESO Garching. The near future developments are also presented and how the new instruments and telescopes will be integrated into the Paranal Science Operations.
We present near-IR long slit spectroscopic data obtained with ISAAC on VLT/ANTU (ESO/Paranal) to produce Bracket gamma and H2 emission line maps and line profile grids of the central 4"×4" region surrounding the central engine of NGC1068. This paper summarizes the results presented in Galliano & Alloin. The seeing quality together with the use of an 0.3" wide slit and 0.3" slit position offsets allow to perform 2D-spectroscopy at 0.5" spatial resolution. The spectral resolution corresponds to 35km s-1. An asymmetric distribution of H2 emission is observed: no H2 emission is detected at the location of the 2.2 μm continuum core, while two conspicuous H2 knots of are detected at about 1" East and West of the central engine. These knots show a projected velocity difference of 140km s-1 that we interpreted as the signature of a rotating disk of molecular material. The H2 emission line profiles appear highly asymmetric with their low velocity wing being systematically more extended than their high velocity wing. A simple way to account for the changes of the H2 line profiles over the entire 4"×4" region, is to consider that the emission of a radial outflow is superimposed over the emission of the rotating molecular disk. We present a model of such a kinematical configuration and compare our predicted H2 emission line profiles to the observed ones.