Carlos Guirao

High efficiency inexpensive 2-slices image slicers

Image slicers are widely used in astronomical instrumentation to increase the resolving power of spectrographs with the maximum throughput. However, the manufacturing costs are usually significant. This paper describes new image slicer simple designs. They provide only two slices but with high throughput and low cost manufacture process. Two prototypes have been evaluated and their performances are reported.

VLT Interferometer Data Flow System: from observation preparation to data processing

In this article we present the Data Flow System (DFS) for the Very Large Telescope Interferometer (VLTI). The Data Flow System is the VLT end-to-end software system for handling astronomical observations from the initial observation proposal phase through the acquisition, processing and control of the astronomical data. The Data Flow system is now in the process of installation and adaptation for the VLT Interferometer. The DFS was first installed for VLTI first fringes utilising the siderostats together with the VINCI instrument and is constantly being upgraded in phase with the VLTI commissioning. When completed the VLT Interferometer will make it possible to coherently combine up to three beams coming from the four VLT 8.2m telescopes as well as from a set of initially three 1.8m Auxiliary Telescopes, using a Delay Line tunnel and four interferometry instruments. Observations of objects with some scientific interest are already being carried out in the framework of the VLTI commissioning using siderostats and the VLT Unit Telescopes, making it possible to test tools under realistic conditions. These tools comprise observation preparation, pipeline processing and further analysis systems. Work is in progress for the commissioning of other VLTI science instruments such as MIDI and AMBER. These are planned for the second half of 2002 and first half of 2003 respectively. The DFS will be especially useful for service observing. This is expected to be an important mode of observation for the VLTI, which is required to cope with numerous observation constraints and the need for observations spread over extended periods of time.

Data flow system for the very large telescope interferometer

The Data Flow System is the VLT end-to-end system for handling astronomical observations from the initial observation proposal phase through the acquisition, processing and control of the astronomical data. The VLT Data Flow System has been in place since the opening of the first VLT Unit Telescope in 1998. When completed the VLT Interferometer will make it possible to coherently combine up to three beams coming from the four VLT 8.2m telescopes as well as from a set of initially three 1.8m Auxiliary Telescopes, using a Delay Line tunnel and four interferometry instruments. The Data Flow system is now in the process of installation and adaptation for the VLT Interferometer. Observation preparation for a multi-telescope system, handling large data volume of several tens of gigabytes per night are among the new challenges offered by this system. This introduction paper presents the VLTI Data Flow system installed during the initial phase of VLTI commissioning. Observation preparation, data archival, and data pipeline processing are addressed.

PUCHEROS: a low-cost fiber-fed Echelle Spectrograph for the visible spectral range

PUCHEROS is a high resolution optical Echelle spectrograph designed for the 50 cm telescope located at the Pontificia Universidad Cat´olica de Chile (PUC) observatory of Santa Martina. With a resolution about 20,000, PUCHEROS is an ideal instrument to study bright and variable objects, our driving science case is the study of bright early type stars. Using a fiber optic to bring the light from the telescope to the instrument, it can be located in a gravity invariant, temperature stabilized location, allowing precise long-term stability. PUCHEROS will be a valuable tool both for research and didactics at the graduate and undergraduate level. In this work we present the optical and mechanical design of the spectrograph as well as the first laboratory tests.

Observatorio UC at Santa Martina: a small observing facility operated by PUC

The Department of Astronomy and Astrophysics (DAA) of the Pontificia Universidad Católica de Chile (PUC) operates a small observatory at Santa Martina hills located in the outskirts of Santiago. Despite the close distance (about 30 km) from the centre of a very large metropolitan area, the observatory offers excellent conditions in terms of number of clear nights and relatively good conditions in terms of light pollution and image quality. The observatory is mostly used for didactic purposes, however we are evaluating scientific applications as well.