LOT Update


The Long Range Plan for Astronomy endorsed a large optical telescope as “strongly recommended”, the same ranking as ALMA has. Canada has been active in LOT studies since Feb 2000 (recall that the wide-field 8m idea had a drop-dead date of one year after its proposal in Feb, 1999). HIA investment in this area is now over C$1M/year which enables a wide range of studies. Also AMEC is co-investor and is very involved in the design studies. A small but exceptionally important element is the NSERC International Opportunities Fund grant of $132,000/year for 3 years which funds travel, meetings and proposal preparation in an exceptionally flexible format. Over the 2002-2005 period something in the $4-$5M range will be spent to keep us competitive in this very rapidly moving field.


The science cases to motivate the construction of extremely large telescopes (ELT) remain remarkably broad, covering everything from fundamental astrophysics to the entire range of “origins” issues. A key case that excites most imaginations is the characterization of extra-solar planets. Going beyond merely discovering planets or their embryonic disks, ELTs will use photometric and spectroscopic techniques to measure rotation periods, look for seasonal effects, examine the atmospheres, and, to begin to go after “biomarkers”. The field has gone from a few papers to a flood of papers on science prospects and instrument concepts in a few years. In cosmology the search for the nature of dark energy and dark matter will continue, using the sensitivity and angular resolution to take the study to higher redshifts and smaller scales (to exploit lensing of the very dense background screen of small galaxies available at low flux levels). The fundamental astrophysics of black holes will be explored, perhaps most intriguingly in our own galaxy where thousands of individual stars will be followed near the event horizon of the BH in our galaxy’s nucleus. Given LISA’s ability (funded, nominal launch of 2012) to “hear” strong gravity phenomena on stellar mass scales over our entire galaxy and super-massive BH’s to redshifts of one hundred there will be entire new tests of gravitation theory. Galaxy formation will be one of the key areas, in conjunction with JWST, ALMA and other telescopes.The general study of star formation and planetary disks will also complement ALMA. The list goes on in virtually every area of astronomy, with these being a few highlights. And of course the tremendous new capabilities will open up new discovery spaces.


Large ground based telescopes are central to the future of various strong institutions and national communities. Moreover, because near diffraction limited performance is part of the base design these 30m class facilities will be about 100 times more powerful than the existing 8-10m facilities. Not surprisingly this has then become an extremely competitive area featuring a number of very strong players. One likely outcome is that several of these facilities will be built. Canada is actively discussing partnerships with essentially all active groups but there is no final resolution of which partnership we join at this time. The benefits of being a founding partner are enormous: it gives us the best chance to realize our own scientific vision and is crucial to our ability to provide the high level of economic return that such a major funding request demands.
One of the ACURA tasks forces is to look after LOT issues, in particular a CFI proposal. The past few months have been an exceptionally vigorous time for LOT activities around the world and in Canada. The Canadian SSC has recommended to OIRAC (both joint CASCA/HIA committees) that we seek a “second to none” position in a telescope of no less than 20m aperture with near diffraction limited performance. There are additional recommendations on matters of detail. We have a couple of lines of fairly strong quantitative argument that indicates that a small share would not be healthy for either scientific impact or economic return.
These scientific requirements lead to a range of very demanding technical requirements which remain ambitious but now clearly in the range of feasibility. The crucial role of Adaptive Optics plays to one of Canada’s greatest technical strengths. The problem of wind loading on mirrors which need to be held in position to a precision of 100 nanometer plays to the strengths of AMEC Dynamic Systems in structures and to a broad group of experts in CFD modeling distributed across our country. These areas of expertise (and others) make Canada an exceptionally desirable partner in one of these facilities. It also makes us a competitive supplier to any project.


Given the goals of our scientific community, we need to raise the funds to achieve them. We have a placeholder CFI proposal for C$125M, which is supported by ACURA. That will allow us to carry out our share of the design studies and put in place an enclosure and much of a telescope structure, as well as start on at least one major instrument. A second funding request of comparable magnitude will be required to complete the project. A successful funding request will then send funds into ACURA (and others) as their managing organization. ACURA will likely have both local management looking after Canadian interests, and will appoint members to the international project board, somewhat like the current CFHT. Various universities, HIA/NRC and not-for-profit labs around the country are able to generate both the matching funds and a reasonable distribution of work to make the proposal work from the point of view of CFI rules. An important aspect is that CFI has implemented “institutional caps” on this proposal round, specifically excepting “national projects” with ten or more institutions that will use the research infrastructure.
So, we have a good idea where we are going, with science, partners, technical work, budget and management. Of course to make it happen we have to fill in a million details and get the funding. The raw probability of success is fairly good, at about 50%, and we will work closely with CFI to ensure that we are consistent with their guidelines.

For your comments, or, more information about any aspect, please contact
carlberg@astro.utoronto.ca