Francisco Diego

Francisco Diego
University College London | UCL · Department of Physics and Astronomy

PhD

About

47
Publications
599
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447
Citations

Publications

Publications (47)
Article
I present a careful selection of fundamental concepts and basic ideas, in order to capture the very essence of the amazing astrophysical discoveries and to make it accesible to the public of all ages as a legacy of IYA2009.
Article
Francisco Diego has some ideas and suggestions for outreach from his experience as RAS Lecturer on the Queen Mary 2 and the Queen Victoria.
Article
Full-text available
The year 2009 offers a unique opportunity to celebrate some of the greatest achievements of humankind to unravel the secrets of nature. It will be 400 years since Galileo extended the human senses by opening a wider window to the Universe; it will be 200 years since Charles Darwin's birth and 150 years since the publication of The Origin of Species...
Article
Recent discoveries about the Universe reveal an amazing panorama of great relevance to the culture of the 21st century. However, as the amount of information and the variety of topics are overwhelming, it is important to capture the essence of these discoveries. I propose here a careful selection of simple and fundamental themes on the nature, dist...
Article
The schools outreach programme at the University of London Observatory includes guided visits to the observatory by school groups and also visiting lectures to schools. Two of the lectures are outlined together with a description of playground solar observing using a portable Ha telescope. Finally, plans for expanding the programme are presented, t...
Article
High-dispersion time-resolved spectroscopy of the unique magnetic cataclysmic variable AE Aqr has been obtained during four bserving runs separated by more than nine years. The high spectral resolution obtained from the AAT and SPM allows us to find the fundamental parameters of the binary. Doppler tomography of the emission lines show that during...
Article
HROS will be the key instrument for high resolution spectroscopy for UV to near-IR wavelengths at eh Gemini South telescope. The instrument is unique in providing a resolving power of R equals 50,000 at the Cassegrain focus of an 8-meter telescope. Taking advantage of this location, the spectrograph is optimized for high throughput, particularly fo...
Article
To fully appreciate the spectacle which is an eclipse the observer needs to know a little about the Sun, its structure and what is expected to occur on 11 August. This article links the structure of the Sun to the magic of a total solar eclipse.
Article
This short contribution presents the demanding requirements of scientific cases for ultra-high stability spectrography, from the study of subtle radial velocity changes induced by asteroseismology to the ones produced by extra-solar planetary companions. The analysis of physical conditions in cool interstellar clouds is presented as a typical appli...
Article
The high resolution optical spectrograph (HROS) for Gemini is currently within its conceptual design phase. The science requirements for this instrument demand spectral resolutions of 50,000 and 120,000 with entrance slits of 0.57 and 0.24 arcsec respectively. Amongst the current large telescope projects, HROS will be the only instrument of its cla...
Article
The high resolution optical spectrograph (HROS) for Gemini is currently within its conceptual design phase. The science requirements for this instrument demand spectral resolutions of 50,000 and 120,000 with entrance slits of 0.57 and 0.24 arcsec respectively. Amongst the current large telescope projects, HROS will be the only instrument of its cla...
Article
Full-text available
ISIS Spectrograph Automatic Active Collimator (ISAAC) was developed at the Optical Science Lab, University College London, as an experimental system to improve the image stability on the detectors of the Intermediate-dispersion Spectroscopic and Imaging System (ISIS) at the William Herschel Telescope (WHT). It is based on the concept of active comp...
Article
In November 1994 a total solar eclipse occurred across south America; the path of totality crossed parts of Peru, Chile and Bolivia and continued as far as the coast of Brazil.A party from University College London with considerable experience in eclipse photography organised an expedition to observe and photograph the eclipse from a high-altitude...
Article
We present high resolution (0.3 km s(-1) ) spectra, obtained with the Anglo-Australian Telescope (AAT) Ultra-High-Resolution Facility (UHRF), of interstellar NaI D_1, D_2 and CaII K absorption towards HD 28497. Numerous absorption components are evident in these spectra with four components showing s-resolved NaI hyperfine structure. If we assume t...
Article
Full-text available
Spectrographs designed or built for the Keck, Gemini, Hobby-Eberly, MMT, and ESO Very Large Telescopes are described and compared to demonstrate principles and constraints in the design of spectrographs for 8-m to 10-m class telescopes. (SECTION: Workshop on High-Resolution Spectroscopy)
Article
The interstellar (7) Li/(6) Li isotope ratio is an important parameter which is governed by primordial nucleosynthesis during the Big Bang and by the chemical evolution of our Galaxy. Reported measurements of this isotope ratio in the interstellar medium thus far have included the following results: (7) Li/(6) Li ~ 38 toward zeta Oph (Ferlet and De...
Article
Full-text available
The Ultra-High-Resolution Facility (UHRF) has been commissioned at the coude focus of the Anglo-Australian Telescope (AAT), and provides a resolving power of R~=10^6. This is the highest spectral resolution ever obtained by an optical astronomical spectrograph, and is intended mainly for astrophysical studies of cool interstellar clouds. This paper...
Article
Full-text available
We present ultra-high-resolution observations of optical interstellar lines towards zeta Oph obtained during the commissioning phase of the new Ultra-High-Resolution Facility (UHRF) at the AAT. The UHRF has achieved its design resolving power of R~=10^6, and has very clearly resolved hyperfine splitting in three of the 11 identified Na I D-line vel...
Article
This paper describes an image slicer based on a modified version of the Bowen-Walraven slicer. The new design is called Confocal Image Slicer, and delivers a large number of slices, all in focus. This allows the slicing of a wider area of the seeing disk, to the benefit of very high resolution spectrographs like the Ultra-High-Resolution Facility,...
Article
We define the stability requirements for a high-resolution spectrograph, then show how these can be met at Cassegrain by modern materials, mechanism design, thermal control, and passive and active compensation for structural flexure. We consider the optimization of the information throughput of the spectrograph, in terms of slit-throughput, with th...
Article
Until recently the study of cool clouds of interstellar matter had been limited by the relatively low spectral resolutions provided by existing spectrographs. The Ultra-High-Resolution Facility (UHRF) recently commissioned at the Anglo-Australian Telescope has changed dramatically this panorama by delivering for the first time resolutions approachi...
Article
This paper describes an image slicer based on a modified version of the Bowen-Walraven slicer. The new design is called Confocal Image Slicer, and delivers a large number of slices, all in focus. This allows the slicing of a wider area of the seeing disk, to the benefit of very high resolution spectrographs like the Ultra-High-Resolution Facility,...
Article
Full-text available
We present ultra-high-resolution observations $(R > 700 \ 000)$ of interstellar CH, $\rm CH^+$ and CN towards $\zeta$ Oph obtained with the newly commissioned Ultra-High-Resolution Facility (UHRF) at the AAT. The molecular lines have all been fully resolved, and we discuss their implications for this well-studied molecular sightline. The CH and CN...
Article
Full-text available
We present ultra-high-resolution observations (R> 700000) of interstellar CH, CH+ and CN towards ζ Oph obtained with the newly commissioned Ultra-High- Resolution Facility (UHRF) at the AAT. The molecular lines have all been fully resolved, and we discuss their implications for this well-studied molecular sightline. The CH and CN lines each consist...
Article
Full-text available
We present observations of the β Pictoris circumstellar Ca II K line, obtained with the new Ultra-High-Resolution facility (UHRF) at the Anglo-Australian Telescope. The resolving power was R ≳ 900000, and these data therefore comprise the highest resolution observations yet obtained of this object. Observations were obtained on three nights in 1993...
Article
Full-text available
We present observations of the β Pictoris circumstellar Ca II K line, obtained with the new Ultra-High-Resolution facility (UHRF) at the Anglo-Australian Telescope. The resolving power was R≥900000, and these data therefore comprise the highest resolution observations yet obtained of this object. Observations were obtained on three nights in 1993 (...
Conference Paper
Until recently the study of cool clouds of interstellar matter had been limited by the relatively low spectral resolutions provided by existing spectrographs. The Ultra-High-Resolution Facility (UHRF) recently commissioned at the Anglo-Australian Telescope has changed dramatically this panorama by delivering for the first time resolutions approachi...
Article
A confocal image slicer for use in high-resolution spectrography in astrophysics is presented. The deviceimproves the light transmission of a high-resolution spectrograph by an (unprecedented) order of magnitude. The production of a prototype is described, and the first astronomical results obtained with the Anglo-Australian Telescope are presented...
Article
The cost of an 8-m telescope is still too high for most national observatories. Cost reductions must involve new technology for the primary mirror: its material and figuring, its mass, handling and the aluminizing plant. The present scheme addresses these problems using some features of the Keck technology, but is simplified. Consideration is given...
Article
The optical design and performance of the UCLES echelle spectrograph, installed at the f/37.7 coude focus of the 3.9-m AAT in June 1988, are described and illustrated with extensive diagrams, drawings, photographs, and sample spectra. The UCLES operates at 300-1100 nm with resolution 30,000-115,000 and adjustable collimated beam size; it employs ei...
Article
The modifications required to construct an echelle spectrograph similar to the UCLES (currently in use on the 3.9-m AAT and described by Walker et al., 1986) for an 8-m-class telescope are discussed in detail and illustrated with diagrams. The design and operational parameters of the UCLES are reviewed, and a direct factor-of-two linear scaling of...
Article
Full-text available
The authors have calculated the theoretical instrumental response function of the Mount Stromlo spectrograph operating with the 130-inch camera. Measurements made with a narrow-line lamp and models based upon them have indicated that this theoretical profile is a fair approximation to the actual one.
Article
Two almost identical echelle spectrographs are under construction: for the 3.9m Anglo-Australian (AAT) and the 4.2m William Herschel (WHT) telescopes. The versatility of the optical design requires the simultaneous control of many mechanical functions, so a high level of automation under computer control is essential. The control and data reduction...
Article
An account is given of the innovative design features incorporated in the echelle spectrographs of the Anglo-Australian and William Herschel telescopes, which have been conceived with a view to the matching of the spectrum format to the features of a the University College London Image Photon Counting System. Attention is given to methods employed...
Article
Full-text available
The basic concepts behind the design of echelle spectrographs being built for the Anglo-Australian Telescope, and proposed for the 4.2-m William Herschel Telescope of the LPO, are described. The astronomical requirements are outlined, followed by consideration of the constraints imposed by the detector. Attention is drawn to the importance of the e...
Article
Full-text available
This paper describes a technique which has been applied to the new AAT coudé échelle spectrograph, under construction at University College London, to increase its throughput without degrading resolution. The effect of illuminating the slit with stellar images and extended objects is considered and a method of increasing the flexibility of the desi...
Article
During 1983, the advisory committee for instrumentation at the Anglo Australian Telescope (AAT) recommended that, as a matter of high priority, an échelle spectrograph should be procured for the f/36 coudé focus. The aim was to satisfy the high spectral-resolution needs of the community which, hereto, have been neglected. We at University College L...

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