We survey the past and the present status of optical and infra-red astronomy in Canada. We then look at the options for the future. Involvement in NGST is currently the highest priority for OIR astronomy. After that, the situation is less clear. The next generation CFHT committee presented a strong case for a very large optical telescope (greater than 25m diameter), that is convincing. However, other options, particularly additional 8m class telescopes, or optical interferometry, also need funded studies as well before any final decision should be made.

In this report, we will try to summarize the facilities currently available to Canadian astronomers in the optical and infra-red wavebands, and to give an overview of the plans for the future. For the purposes of this report, we will take the optical and infra-red to include the wavelengths from 300nm to 30 microns. This very arbitrary division excludes space based UV astronomy, and also the spectral regions covered by facilities such as the James Clerk Maxwell Telescope. It is hoped that the former will be adequately discussed in the submission from the Joint Subcommittee for Space Astronomy, while the latter is discussed by the submission from the Radio subcommittee.

It is probably worth reiterating here that such arbitrary wavelength divisions are something of a historical artifact, left over from the days when it was impossible to gather data at any waveband without a deep understanding of the (often arcane) instruments and technology. Thus observational astronomers of the past specialized in certain wavebands. Nowadays, thanks to powerful reduction and analysis software, this specialization is no longer necessary, and it is common practice for younger (and many older) astronomers to combine data from X-ray through to centimeter wavelengths in their efforts to understand some part of the Universe. It is therefore important not to take this report in isolation, or to try to ask questions such as "What needs to be done to support optical astronomers?" as they are an increasingly small fraction of the community. The appropriate questions are more along the lines of "What are the best avenues at any wavelength to making exciting new discoveries?" Undoubtedly, many of these promising avenues do lie in the optical through infra-red wavebands, but they must be considered in context.

This report is in some sense a synthesis of several other reports, all available on the LRPP web site. These are:

• The Present and Future of HIA Telescopes in Victoria
• CFHT: 2000 and Beyond
• The Report of the Next Generation CFHT Committee
• Next Generation Space Telescope

We will break the report into three sections describing the past, the present and the future.

The optical and infra-red regions of the electromagnetic spectrum have been a very rich ground for spectacular discovery in astronomy, ever since Galileo first trained his telescopes on the moons on Jupiter. While Galileo was not strictly speaking Canadian, there have been many dramatic contributions to world astronomy from Canadians observing in these wavelengths. A few examples include: the work on the structure of the galaxy done with the DAO 1.8m telescope in the early parts of the century, the discoveries on the evolution of stars and the age of the universe from studies of star clusters – widely recognized to be a Canadian science, and more recently the work on galaxy evolution done at CFHT by the Canada-France Redshift Survey team and the Canadian Network for Observational Cosmology. It is reasonable to expect that many further stunning discoveries await us in the wavelength region, and that Canadian astronomers will be leading the chase in many occasions. It remains a fact of physics that many atoms and ions emit the bulk of their diagnostic radiation into the optical and infra-red. Information in this waveband has been an essential complement to work at all other wavelengths, e.g. finding redshifts of radio galaxies, measuring the velocity dispersions of hot X-ray emitting clusters of galaxies, or identifying the objects producing submm radiation detected by SCUBA on JCMT. Below, we describe the evolution of the facilities available to Canadians, and discuss what will be needed in the future to enable continued Canadian leadership.

Canadians have generally been well supplied with fore-front observational facilities. Listing facilities in this section in no way implies that their time is past, merely that they have been available for some time.

1-2m Class Onshore facilities

Starting back at the beginning of the century, Canadians have had access to a number of (for their time) powerful telescopes. These include the DDO 1.9m, the DAO 1.8m, the Mt. Megantic 1.5m and the University of Western Ontario 1.2m. An eloquent case for the support and role of such facilities has been made in the LRPP submission: The Present and Future of HIA Telescopes in Victoria.

Canada-France-Hawaii 3.6m Telescope

The CFHT saw first light in 1979, and has been one of the best 4m class telescopes ever since. The excellent site, combined with world beating instrumentation, has given Canadian astronomers an edge in the competitive world of astronomy.

US National Facilities

Canadians have been very successful in winning time on US national facilities (which are generally awarded in an open fashion to date). Canadians have won large amounts of observing time at the NOAO facilities in Arizona and Chile. However, it must be stated that this arrangement is not a good way to build a strong community. Canadians have no control over the science focus of these telescopes, and no input on the new instrumentation. Existing solely as a parasite on US facilities would inevitably lead to the loss of the best people (both technical and astronomers) to the US, where they will be able to directly influence the future of astronomy.

Here we list not only resources that are available in 1998, but also things that are expected or needed in the next few years.

Canada-France-Hawaii 3.6m Telescope

The current situation at CFHT has been well summarized in the LRPP submission: CFHT: 2000 and Beyond. The most urgent requirements here seem to be the implementation of the Megaprime camera, and the proposed wide field Infra-red imager. Timely implementation of both of these are essential, and ways of speeding up their delivery need to be investigated. It should be re-emphasized that, in the era of 8m telescopes, the 4m class telescopes will have to specialize. Once they have done that, it will be crucial that Canadians have access to many (or even most) of the other 4m class telescopes in the world, where other specialized instruments exist. At the moment this is done in a rather haphazard way through the generosity of Telescope Allocation Committees, but a more coordinated approach, with (no doubt complex) multi-national agreements would definitely be more efficient at producing science.

The Hubble Space Telescope

Although not a Canadian facility, Canadians have been very successful at winning time on the HST, also serving on several of the science key project teams and even the instrument teams. Thanks to the voluminous (and highly praiseworthy) NASA publicity, this fact may sometimes get buried. In some sense this exemplifies the problem stated above. If we are not an active partner in a project, with involvement financially, technically and scientifically, it is hard to take the lead, and hence very hard to gain recognition.

The Gemini 8m Telescopes

The Gemini telescopes are the next great Canadian hope for exciting discoveries in the optical and infra-red wavebands. They are proving to be a model for future collaborative projects, and Canadians are heavily involved in all the stages of their use, from Canadian industry building the domes, through Canadian instrumentation projects in the fore-front areas of multi-object spectrographs and adaptive optics, finishing with complete Canadian control of the allocation of our share of the telescope time. We have been very active and influential in for a discussing the long term plans for instrumentation, and the Gemini future looks very bright. The only possible dark spot in this bright future is the disappointingly small share Canada has in the expected world-wide suite of 8m telescopes. Operations funding for Gemini wisely include a significant budget for future instrumentation. This is crucial for Gemini to remain exciting and competitive, and the request for protection against inflation in this budget is very important.

We discuss here the possibilities and priorities for the future. While some priorities seem abundantly clear (for example Canadian involvement in NGST), other possibilities require further study. In particular, it is premature to make choices between most of the items listed below without some real experience with using 8m class telescopes, and some further crystallization of the capabilities of NGST. Funding for scientific and engineering studies of the options below is clearly needed.

1-2m Class Telescopes

Mel Blake has made an interesting case in the LRPP discussion forum for a new 1-2m class telescope in the south.

Next Generation Space Telescope

A comprehensive description of the scientific possibilities of NGST, and describing how Canada can be involved has been given in the LRPP submission: Next Generation Space Telescope. The arguments in favor of Canadian involvement seem overwhelming, and the predicted capabilities of this telescope are astonishing. Assuming that the telescope flies successfully, it will dramatically influence future ground based developments, basically driving one towards huge telescopes in order to compensate for the higher background found on the ground.

Additional 8m Class Telescopes

A case for replacing both the University of Hawaii 88 inch telescope and also, afterwards, the CFHT itself with 8m class telescopes is made in the LRPP submission: CFHT: 2000 and Beyond. The obvious attraction is that this is a known technology, and in principle Canada could afford to be a dominant partner in such a project. It is more difficult to say whether a niche can be found for such telescopes in an era of multiple 8m class telescopes, although certainly deserving of further study.

Optical Interferometry

Optical interferometry is still in its infancy, and its ultimate capabilities are not yet clear. In many ways this is one of the attractions, in that there are opportunities to become a world leader in this area. A case for moving into this area is made in the submission by John Lester to the LRPP discussion.

Very Large Optical Telescope

The ‘ne plus ultra’ of ground based telescopes in the optical and infra-red seems likely to be the OWL proposal from the Europeans for a telescope with a 100m aperture. A scientific case for a telescope of 25m diameter or larger is made in the LRPP submission: The Report of the Next Generation CFHT Committee. There seems little doubt that if such a telescope can be built, large increases in sensitivity would be achieved, and experience to date shows that unexpected and thrilling new discoveries will then follow. Funding for further study of this option, within Canada is essential. With Canada’s world wide recognition as a leader in Adaptive Optics technology, this could well be one area to focus on.

Canadians have had access to excellent facilities in the optical and infra-red wavebands in the past (e.g. CFHT), and seem set to have access to such facilities in the near future (e.g. Gemini). This obviously does not mean that we should rest on our laurels. In order to remain at the forefront in modern astronomy it is necessary to be closely involved both scientifically and technically with fore-front projects at all wavebands. A first priority is involvement in NGST. Beyond that, funding the studies needed to be a serious collaborator in new world class projects (further 8m, optical interferometry or a very large optical telescope) is essential.