Infrared interferometry with single telescopes

We examine the merits of three basic interferometric techniques using two-dimensional infrared arrays: speckle interferopmetry, pupil plane interferometry, and speckle holography.Paper presented at the Symposium on the JNLT and Related Engineering Developments, Tokyo, November 29–December 2, 1988.     

Infrared detector for mid-infrared astronomy

Recent developments of infrared detectors and arrays for mid-infrared astronomical observations are discussed with an emphasis on technical issues in designing and fabricating photometers and cameras. The discussion includes a small-scale silicon bolometer array being tested at the Steward Observatory.Paper presented at the Symposium on the JNLT and Related Engineering Developments, Tokyo, November 29–December 2, 1988.     

Infrared instruments for JNLT

The principal features of the JNLT as an infrared telescope are presented along with its ultimate performance of detectivity in typical methods of imagery and spectroscopy. Some infrared instruments: infrared camera, grating spectrometer, and Fabry-Pérot-based imager, currently proposed as the first generation instruments are also discussed in relation to the scientific objectives of the JNLT.Paper presented at the Symposium on the JNLT and Related Engineering Developments, Tokyo, November 29–December 2, 1988.     

Cosmology and large telescopes

Assuming a large collecting area, a good angular resolution and a large field of view expected for the Japanese National Large Telescope (JNLT), we demonstrate that JNLT will provide a useful means of studying cosmological objects of interest. Among them I discuss how cosmological parameters and evolutionary effects can be obtained from redshift-magnitude relations, galaxy counts, distant supernovae, quasar properties, and large-scale structures. An advantage of near infrared observations is emphasized.Paper presented at the Symposium on the JNLT and Related Engineering Developments, Tokyo, November 29–December 2, 1988.     

Outline of the JNLT project

The Japanese National Large Telescope (JNLT) is a 7.5 m reflector with a monolithic thin meniscus main mirror, having the candidate construction site on the northwest cone of the Mauna Kea, Hawaii.The present concept of JNLT has the characteristics of a third generation infrared telescope, which should be capable of various observations of high spatial resolution in the optical-infrared region.Although the project is still under examination from the financial and administrative point of view, a wide range of technical studies were carried out by the JNLT Working Group with the collaboration of specialists from the academic and the industrial sectors.Paper presented at the symposium on the JNLT and Related Engineering Developments, Tokyo, November 29–December 2, 1988.     

Fast optics for large telescopes

Reports on two optical designs studied in connection with the JNLT project: namely, the primary corrector and the camera for a spectrograph, are presented.Paper presented at the symposium on the JNLT and Related Engineering Developments, Tokyo, November 2–December 2, 1988.     

Can the optical very large array be coupled with the JNLT?

Coupling the JNLT with the Keck telescope is of considerable interest. Further enhancement may be possible with auxiliary small telescopes, as planned for ESO's VLT. Current plans for installing the optical very large array at Mauna Kea provide opportunities for extra OVLA telescopes near the JNLT.A coudé field slicer is proposed for interferometric observing of a reference star together with the main object. Additions to the JNLT coudé spectrograph are also suggested for use as a speckle camera with multiple spectral channels.Paper presented at the Symposium on the JNLT and Related Engineering Developments, Tokyo, November 29–December 2, 1988.     

Active optics experiments for thin meniscus mirror

The concept of the active support system for JNLT is summarized. Performance of the force sensor, the optical wavefront analyzer, and the actuator under development for JNLT is reported. The results of a series of active optics experiments carried out by assembling these elements to support, measure, and actively correct a 62 cm thin mirror are described.Paper presented at the symposium on the JNLT and Related Engineering Development, Tokyo, November 29–December 2, 1988.     

Operational and technological developments for UKIRT

There are a number of parallels between the UKIRT and the JNLT both of which are major astronomical facilities of nations which do not have premier observing sites in their own country. Some elements of experience with UKIRT relevant to the JNLT are described. These include matters related to personnel and to instruments.Paper presented at the Symposium on the JNLT and Related Engineering Developments, Tokyo, November 29–December 2, 1988.     

Some comments on large telescope astronomy in Britain and Australia

Many of the major British telescopes are described in this volume by other speakers directly involved with those facilities, so this contribution will concentrate on aspects of the operation of the Anglo-Australian Observatory (AAO) which seem particularly relevant to the JNLT. Some requirements for the success of the new very large optical telescopes are also discussed.Paper presented at the Symposium on the JNLT and Related Engineering Developments, Tokyo, November 29–December 2, 1988.     

Mechanical structure of JNLT

The Japanese National Large Telescope (JNLT) requires mechanical performance of high tracking accuracy to achieve good image quality and a mechanical configuration to provide several kinds of focus modes. Under these requirements, a conceptual design for the JNLT mechanical structure has been performed. This paper presents the results of the conceptual design currently under consideration.Paper presented at the symposium on the JNLT and Related Engineering Developments, Tokyo, November 29–December 2, 1988.     

The interferometric mode of the European Very Large Telescope

The European Very Large Telescope program has been approved in 1987. It aims to consists of an array of four 8 m telescopes, plus two additional 2 m class auxiliary telescopes, the latter being fully dedicated to optical (infrared and visible) interferometry, with possible combination of some and, in the long term, all large telescopes. We discuss the implementation of this program in the next ten years.Paper presented at the Symposium on the JNLT and Related Engineering Developments, Tokyo, November 29–December 2, 1988.     

Recent developments at Canada-France-Hawaii Telescope

Recent developments at CFHT are described with particular emphasis in the following areas: image quality, techniques for high-resolution imaging, computers, and communications.Paper presented at the Symposium on the JNLT and Related Engineering Development, Tokyo, November 29–December 2, 1988.     

Cooperation aspects of international observatories

From the user's point of view, it is essential to promote collaborations to make full use of large telescopes, by covering the wide range of the wavelengths. To do that efficiently, it is necessary to work with other facilities, often abroad. Other talks in this symposium are concerned about the spatial resolution or the coverage at one wavelength or one to two octaves in wavelength. Though the above is important, that is not enough to attach the mysteries in the Universe, since a considerable amount of energy is emitted in the infrared, and mass exists in molecular gas form. In this paper, two examples of international, multiwavelength work are shown which turned out to be beneficial for the world-wide community. One is the Japan-U.K. arrangement mainly between the radio and infrared facilities, and the other is the arrangement around James Clerk Maxwell Telescope (JCMT), challenging a new regime of the observational astronomy.Paper presented at the Symposium on the JNLT and Related Engineering Developments, Tokyo, November 29–December 2, 1988.     

Some new astronomical facilities in China

For the 1990's, plans for some astronomical facilities and related researchers are being carried out in China. In this report we describe in some details the plans of radio astronomical facilities, 150/220 cm Schmidt telescope, and experiments on porcelain mirror material.Paper presented at the Symposium on the JNLT and Related Engineering Developments, Tokyo, November 29–December 2, 1988.     

Radio astronomy and very large telescopes

The current achievements of the observational abilities of radio astronomy is briefly reviewed putting emphasis on the imaging capability. The new projects in radio astronomy are discussed in connection with the new generation of optical/IR telescope projects.Paper presented at the Symposium on the JNLT and Related Engineering Developments, Tokyo, November 29–December 1988.     

Spectral speckle interferometry

A method of obtaining an objective prism spectrum of a stellar object with diffraction-limited spatial resolution is described.Paper presented at the Symposium on the JNLT and Related Engineering Developments, Tokyo, November 29–December 2, 1988.     

Optical instruments for JNLT

The plan for optical instruments for the Japanese National Large Telescope is described. Performance of the first-generation instruments is computed on the basis of tentative designs, and the capability of the telescope is demonstrated.Paper presented at the Symposium on the JNLT and Related Engineering Developments, Tokyo, November 29–December 2, 1988.     

The UK Large Telescope project

The current status and the organization of the UK Large Telescope programme are summarized. Some scientific and design issues are discussed on the basis of work done for the SERC Large Telescope Panel report. A national Phase A programme is now underway addressing more detailed aspects of these questions. This study will culminate in a final proposal for funding in 1990.Paper presented at the Symposium on the JNLT and Related Engineering Developments, Tokyo, November 29–December 2, 1988.     

Evaluation of the JNLT site

Two steps have been taken to decide at what place and altitude to set up the JNLT on Mauna Kea. First, the wind tunnel experiment has been made in collaboration with the Institute of Meteorology using the two models of summit area with the reduced scales of 1/1000 and 1/5000. This study tells us that the north-west cone is suitable for JNLT. Secondly, we have done the measurement of the microthermal activities in this area with a 30 m tower, which was continued for about 4 months in collaboration with the University of Hawaii. This experiment has given the mean vertical profile ofC _T ² over 4 months and its scale height in the boundayr layer on our site. By use of these measurements, the contribution of the boundary layer to seeing is estimated. The behaviour ofC _T ² under strong winds can be explained very well by topographic effects, which is in fairly good agreement with the results of our wind tunnel experiment.Paper presented at the Symposium on the JNLT and Related Engineering Developments, Tokyo, November 29–December 2, 1988.