Jose Luis Rasilla

ESPRESSO: the Echelle spectrograph for rocky exoplanets and stable spectroscopic observations

ESPRESSO, the Echelle SPectrograph for Rocky Exoplanets and Stable Spectroscopic Observations, will combine the efficiency of modern echelle spectrograph design with extreme radial-velocity precision. It will be installed on ESOs VLT in order to achieve a gain of two magnitudes with respect to its predecessor HARPS, and the instrumental radialvelocity precision will be improved to reach cm/s level. Thanks to its characteristics and the ability of combining incoherently the light of 4 large telescopes, ESPRESSO will offer new possibilities in various fields of astronomy. The main scientific objectives will be the search and characterization of rocky exoplanets in the habitable zone of quiet, nearby G to M-dwarfs, and the analysis of the variability of fundamental physical constants. We will present the ambitious scientific objectives, the capabilities of ESPRESSO, and the technical solutions of this challenging project.

OSIRIS tunable imager and spectrograph for the GTC. Instrument status

OSIRIS (Optical System for Imaging and low Resolution Integrated Spectroscopy) is the optical Day One instrument for the 10.4m Spanish telescope GTC to be installed in the Observatorio del Roque de Los Muchachos (La Palma, Spain). This instrument, operational in mid-2004, covers from 360 up to 1000 nm. OSIRIS observing modes include direct imaging with tunable and conventional filters, long slit and multiple object spectroscopy and fast spectrophotometry. The OSIRIS wide field of view, high efficiency and the new observing modes (tunable imaging and fast spectrophotometry) for 8-10m class telescopes will provide GTC with a powerful tool for their scientific exploitation. The present paper provides an updated overview of the instrument development, of some of the scientific projects that will be tackled with OSIRIS and of the general requirements driving the optical and mechanical design.

OSIRIS tunable imager and spectrograph

The Optical System for Imaging and low Resolution Integrated Spectroscopy (OSIRIS) will be a Day-One instrument of the Spanish 10.4 m telescope Gran Telescopio Canarias, whose first light is planned for 2002. GTC will be installed at the Observatorio del Roque de los Muchachos in La Palma, Spain. OSIRIS three primary modes are imaging and low resolution long slit and multiple object spectroscopy. The instrument is designed to operate from 365 to 1000 nm with a field of view of 7 by 7 arcminutes and a maximum spectral resolution of 5000. Among the OSIRIS main features are the use of tunable filters for direct imaging, the use of Volume Phase Holographic Gratings as dispersive elements for spectroscopy, and the implementation of an articulated camera to provide maximum spectroscopic efficiency and versatility. Here we present a general description and an overview of the main instrument characteristics.

EMIR: the GTC NIR multi-object imager-spectrograph

In this contribution we review the overall features of EMIR, the NIR multiobject spectrograph of the GTC. EMIR is at present in the middle of the PD phase and will be one of the first common user instruments for the GTC, the 10 meter telescope under construction by GRANTECAN at the Roque de los Muchachos Observatory (Canary Islands, Spain). EMIR is being built by a Consortium of Spanish, French and British institutes led by the IAC. EMIR is designed to realize one of the central goals of 10m class telescopes, allowing observers to obtain spectra for large numbers of faint sources in an time-efficient manner. EMIR is primarily designed to be operated as a MOS in the K band, but offers a wide range of observing modes, including imaging and spectroscopy, both long slit and multiobject, in the wavelength range 0.9 to 2.5 μm. The present status of development, expected performances and schedule are described and discussed. This project is funded by GRANTECAN and the Plan Nacional de Astronomía y Astrofísica (National Plan for Astronomy and Astrophysics, Spain).

Bidimensional spectroscopy with optical fibers at the William Herschel and Nordic Optical Telescopes

In this communication we describe two optical fiber systems contrived to perform simultaneous bidimensional spectroscopy of extended objects: 2D_FIS and HEXAFLEX II. The main component of 2D_FIS is an optical fiber bundle which links the auxiliary Cassegrain focus of the 4.2 m William Herschel Telescope (WHT) with the ISIS spectrograph. HEXAFLEX II has been designed for the Cassegrain focus of the 2.5 m Nordic Optical Telescope (NOT) and it uses the FLEX spectrograph. Both telescopes are at the Observatorio del Roque de los Muchachos, on the island of La Palma. The basic component, the fiber bundle, is similar in both systems although each one is adapted to the particular characteristics of the corresponding spectrograph and telescope. Each one of the bundles is composed of 125 fibers: 95 to observe the object and 30 to obtain the sky background signal. Details of the acquisition procedures are provided. These systems have been tested at the telescope with success. Some examples of results on astronomical objects are shown.

Design and performance of the ESA Optical Ground Station

The European Space Agency (ESA) has undertaken the development of Optical Data Relay payloads, aimed at establishing free space optical communication links between satellites. The first of such systems put into orbit is the SILEX project, in which an experimental link between a GEO satellite (ARTEMIS) and a LEO satellite (SPOT IV) will be used to relay earth observation data. In order to perform In Orbit Testing (IOT) of these and future optical communications systems, ESA and the Instituto de Astrofisica de Canarias (IAC) reached an agreement for the building of the Optical Ground Station (OGS) in the IAC Teide Observatory, which consists basically of a 1-meter telescope and the suitable instrumentation for establishing and testing bi-directional optical links with satellites. The presence of the atmosphere in the data path posses particular problems, with an impact on the instrumentation design. The transmission, reception and measurement functions, along with the overall control of the instruments, are performed at OGS by the Focal Plane Control Electronics (FPCE). The design and performance of this instrumentation is presented, emphasizing the Pointing, Acquisition and Tracking, the Tuneable Laser and the Master Control.

OSIRIS tunable imager and spectrograph for the GTC: from design to commissioning

OSIRIS (Optical System for Imaging and low Resolution Integrated Spectroscopy) was the optical Day One instrument for the 10.4m Spanish telescope GTC. It is installed at the Observatorio del Roque de Los Muchachos (La Palma, Spain). This instrument has been operational since March-2009 and covers from 360 to 1000 nm. OSIRIS observing modes include direct imaging with tunable and conventional filters, long slit and low resolution spectroscopy. OSIRIS wide field of view and high efficiency provide a powerful tool for the scientific exploitation of GTC. OSIRIS was developed by a Consortium formed by the Instituto de Astrofísica de Canarias (IAC) and the Instituto de Astronomía de la Universidad Nacional Autónoma de México (IA-UNAM). The latter was in charge of the optical design, the manufacture of the camera and collaboration in the assembly, integration and verification process. The IAC was responsible for the remaining design of the instrument and it was the project leader. The present paper considers the development of the instrument from its design to its present situation in which is in used by the scientific community.

Performances of NIR VPHGs at cryogenic temperatures

We summarize the performances measured at room temperature and in cryogenic conditions of a set of NIR Volume Phase Holographic Gratings (VPHGs) which can then be used in astronomical instrumentations. VPHGs are novel optical components which can replace standard transmission gratings. Instead of a surface modulation a diffraction index modulation printed in a volume of material generates the diffraction according to the required specifications. Results on transmission and wavefront deformation are presented and compared in the two temperature regimes. These results were achieved along the run of the Joint Research Action 6 of OPTICON FP6 programme whose participating institutions are Osservatorio Astronomico di Brera (INAF), Instituto de Astrofísica de Canarias, Centre Spatial de Liege, Politecnico di Milano and European Southern Observatory.

The participation of the Instituto de Astrofísica de Canarias in the European Solar Telescope

This communication reviews the participation of the Instituto de Astrofísica de Canarias (IAC) in the design of the European Solar Telescope. Apart of being the coordinator institution of the whole project, and, as such, responsible for the project managing, the IAC leads several tasks like overall instrument definition or characterization of the atmospheric turbulence profile with height or the definition of adequate detectors. More in particular, the IAC will design and build two long-base SHABAR (SHAdow BAnd Ranger), instruments to measure medium-altitude seeing. The IAC is also responsible for the design, together with other institutions, of the design of grating spectropolarimeters suitable for multiwavelength high spatial and spectral resolution.

EMIR: THE GTC NIR MULTI-OBJECT IMAGER-SPECTROGRAPH

no nal global y el desempe~ de EMIR, el espectr ografo para objetos m ultiples del NIR del GTC, como tambi en el plan para su aplicaci on cient ca inicial. EMIR, actualmente en sus fases nales, ser a uno de los primeros instrumentos para usuarios del GTC, el telescopio de 10 metros en construcci on por GRANTECAN en el Observatorio del Roque de los Muchachos (Islas Canarias, Espa~ A EMIR lo construye un consorcio de institutos espa~ y franceses conducido por IAC. EMIR est a dise~ para llevar a cabo uno de los objetivos centrales de los telescopios de la clase de 10 metros, lo que permitir a a los observadores obtener espectros de gran n umero de objetos d ebiles de una manera ecien te en cuanto al tiempo. EMIR est a dise~ para ser operado primariamente como un MOS en la banda K, pero ofrece adem as un amplio rango de modos observacionales, incluido imagen y espectroscop a, tanto de rendija larga como de objetos m ultiples, en el rango de longitudes de onda de 0.9 a 2.5 m. Se encuentra equipado con dos subsistemas novedosos: una m ascara de rendijas m ultiples rob otica recongurable y elementos dispersivos formados por una combinaci on de rejilla de difracci on y prismas convencionales de alta calidad, ambos localizados en el coraz on del instrumento. Se describe y discute el estado actual de desarrollo, el desempe~ esperado, el calendario y los planes de aplicaci on cient ca. Este proyecto est a nanciado mayormente por GRANTECAN y el Plan Nacional de Astronom a y Astrof sica de Espa~ na.