CCAT: Cornell-Caltech Atacama Telescope (pronounced "See-cat")

Link to CCAT Web site

I. General project/facility description

1. Overview of the facility/project
   The CCAT is a joint project of the California Institute of Technology and Cornell University, to design and build a 25-m class submm telescope at a high altitude site in the Atacama region. The project is currently in a 2-yr Study Phase that will extend to Spring 2006. Current projections foresee an Engineering Design Phase to initiate after that, with construction leading to first light by 2012-3.

2. Managing institution and organization
   The organization of the project is currently outlined in a MOU signed by Caltech and Cornell in February 2004. A Project Office has been set up, with a Project Manager resident in Ithaca and Deputy Project Manage in Pasadena. Two scientists, one from Caltech and one from Cornell share responsibilities of Project Scientists. The Project Director is from Cornell. An Oversight Committee of 8 members - four each from Caltech and Cornell - plus the Project Director, oversee the management of the project.

3. Funding source(s)
   Funding of the project in its current phase is provided in the measure of 50% by Caltech and JPL, and the remainder 50% by Cornell University. A small contribution has been made by NSF/AST in support of the site study effort.

4. Construction history and cost
   Obviously, no information can be provided at this stage on construction and operational history. One of the main purposes of the Study Phase is precisely that of providing reliable estimates of construction and operational costs. At this stage, it is estimated that the construction costs will not exceed $100M (in 2004 $).

5. Operational history and cost
   Future facility; NYA.

II. Technical details

1. Specifics of telescope/instrument
   Future facility; NA. Currently under study.

2. New capabilities anticipated/planned in next 5-10 years
   When complete in 2013, the CCAT will be a single aperture, approximately 25 m in diameter, and will deliver 2" resolution at 200 µ, its shortest wavelength of operation. Its size is dictated by the specification that the instrument be not confusion limited at wavelengths shorter than 0.5 mm, with integration times of one day. Its main operational bands will be at 200, 350, 450, 650 and 850 µ. The point source sensitivity, equipped with a bolometer array at 350 µ, is expected to be about 0.25 mJy (5 sigma) in 10,000 sec. The telescope will be equipped with large format bolometer arrays operating at the main bands. The comparative effort in the development between bolometer and superheterodyne spectral capabilities remains to be decided.
   CCAT characteristics are planned to take maximum advantage of the fast developing field of bolometer arrays. During operation of the CCAT, arrays with >10K elements are expected to be operational. Hence the telescope is being designed with a wide field of view, of order of 15'.

III. User profile

1. % of "open skies" time
   Currently a project under development by academic research institutions, the outlook for CCAT utilization is to benefit principally researchers at the managing institutions. However, it is considered desirable - both for the health and diversity of the scientific output and for the technical excellence of the telescope instrumentation - that community participation be welcome under an "open skies" policy, that may involve on order of 1/4 of the telescope time. Both Caltech and Cornell operate facilities - through agreements with NSF - widely used by the nationaland international scientific community, and are keenly aware of the benefits of wide community access to the facilities.
   At this stage, no discussions have been initiated with NSF on the specific mode of a possible partnersip, but this issue will surely mature, as the project progresses into its more advanced phases.

2. Institutional affiliations of users
   Future facility; NYA.

3. Student access, involvement, usage
   Future facility; Graduate students are currently involved in various aspects of design study as well as the site survey.

IV. Science Overview

1. Current forefront scientific programs
   Future facility; NA.

2. Major discoveries (through 1999)
   Future facility; NA.

3. Science highlights of last 5 years
   Future facility; NA.

4. Main **future** science questions to be addressed
   
   • Early evolution of galaxies through studies in the 200 µ and 350 µ windows. In 10,000 sec, CCAT will be able to detect sources with a star formation rate of ~30 solar masses per year up to z=3, and with a star formation rate of ~50-100 solar masses per year at all redshifts. Deep surveys will reveal hundreds of thousands of high z galaxies, and access to multiple submm bands will provide photometric redshifts which will allow the study of the evolution of large-scale cosmic structure in the early Universe.

   • Clear access to the Wien side of the Cosmic Microwave Background radiation field, combined with high discrimination of background sources, will allow technically difficult applications of the CMB as a cosmic probe, e.g. the measurement of peculiar velocities of distant clusters, via the kinematic Sunyaev-Zel'dovich effect.

   • Circumstellar disks will be mapped in exquisite detail and, through polarization measurements, the topology of magnetic fields over the large solid angles subtended by the gaseous envelopes of star forming regions will be revealed.

   • The detection of the thermal emission of distant Solar System bodies, such as Kuiper Belt Objects, is currently limited to the largest among such objects, such as Pluto and Charon. This limitation is due to the fact that submm apertures that are sensitive enough are also confusion limited in relatively short integration times. CCAT will be able to detect KBO objects with sizes down to 150 km, with reasonable integration times, thus making possible the direct determination of their albedos and size function, as hundreds of thousands of such objects will be accessible targets. They will be common, serendipitous detections during otherwise targeted wide field surveys.

5. Synergies with other major forefront facilities
   Projected to start operations by 2013, predictions of CCAT discovery profile are likely to be grossly premature. What is clear, however, is the important and unique niche its characteristics will carve.
   • ALMA
     CCAT is to be located at very high altitude - even higher than ALMA -, so that high transparency will be assured at wavelengths to the IR atmospheric cutoff, shortwards of 200 µ. Instrumented with bolometer arrays, at the shorter wavelengths of operation CCAT will be even more sensitive than ALMA, and will have a much larger field of view. CCAT and ALMA will have superb complementarity: CCAT will carry out extensive and sensitive wide field surveys, ALMA will provide the high angular resolution follow-up.

   • SAFIR
     In the longer term, the AASC decadal report has recommended that NASA pursue the development of an ambitious submm/FIR ~10m cold space telescope, known as "SAFIR", to follow onto Spitzer and Herschel, with a launch perhaps in the 2020 time frame. The CCAT would be a key scientific and technological precursor/complement for SAFIR, demonstrating the detector array technology needed for SAFIR, and providing crucial data on the population of dusty galaxies at high redshifts. As a consequence, the construction and operation of the CCAT could facilitate a substantial Cornell/Caltech participation in the SAFIR mission.

6. Unique contributions
   CCAT will yield unique access, with meaningful sensitivity, to the shortest submm bands from the ground. With a significantly larger collecting area, located at a superior site and with access to multiple submm atmospheric windows, the AT will easily outclass existing 10m--class submm facilities such as APEX, CSO and the JCMT. Operating at shorter wavelengths and, at a superior site, it will be far less vulnerable to source confusion and better suited to deep surveys than the LMT. It will be larger, more accessible and have wider sky coverage than the SPT.

V. Education/Outreach activities

1. Visitor facility
   Future facility; NYA.

2. Student programs
   Future facility; NYA.
   Since both Cornell and Caltech are educational institutions, it is a given that students at both the graduate and undergraduate level will be involved in CCAT at all phases.

VI. Documentation/website URLs

1. URL of facility website
   Given the early development stage of othe project, much of the documentation is still in a limited-access stage. A website is maintained at http://www.astro.cornell.edu/research/projects/atacama with some public access material. Most of the technically sensitive materials are however currently only accessible to people internal to the project.

2. URL of EPO website
   Future facility; NYA.

3. URL(s) of any brief overviews of project/facility
   
4. URL(s) of miscellaneous documentation