The role of the national observatories within a changing international landscape of astronomical research and facilities was a fundamental topic of discussion for the Astronomy and Astrophysics Survey Committee (AASC). Inspired by the report of a cross-panel (representation from all relevant panels) on the national observatories, the policy panel and the "O/IR Astronomy from the Ground" panel converged on a philosophical approach for the community that leads to a new vision of the complementary roles of NOAO, the independent observatories, and the funding agencies. This philosophical approach is that the entire suite of facilities and capabilities for ground-based O/IR astronomical research should be viewed as a single systemand that improvements in that system should go forward in a coordinated way.
The AASC recognized that this role of overseer, or steward, for the system is a new one for NOAO, and one which NOAO is not now structured to undertake. Thus, the committee recommended that NOAO, AURA, and the NSF work together to develop and implement a transition plan, and that this plan and NOAO's progress in carrying out this new role be reviewed periodically.
Within this new context, several new initiatives that suppose NOAO involvement are put forward in the AASC and panel reports.
The Giant Segmented-Mirror Telescope (GSMT) is the highest priority large ground-based initiative (second, after NGST, for space and ground combined). GSMT is a 30-meter class, AO-equipped, optical and infrared telescope that will provide complementary capabilities to (and will be coeval with) NGST. Through observations at high spatial and spectral resolution, GSMT is expected to make major contributions to our understanding of star and planet formation, formation and early evolution of galaxies, and the star formation history of nearby galaxies. A wide-field, seeing-limited mode will permit extremely large-scale spectroscopic surveys to explore such topics as the evolution of large-scale structure and the detailed history of the stellar population of the halo of the Milky Way. GSMT is envisioned to be developed as a partnership, as either a US public/private effort or an international effort. NOAO is expected to initiate a strong program to position the community for effective participation.
The next priority of the O/IR panel is the Large-Aperture Synoptic Survey Telescope (LSST). This is a 6.5-meter class, wide-field telescope with the ability to map the entire accessible sky to 24th magnitude (in one optical band) over the course of three nights. Through a single set of observationsand an innovative operations modeLSST would revolutionize our knowledge of astronomical sources that vary or move. Observations with LSST would locate 90% of all Near Earth Objects down to 300 meters in size, enable computation of their orbits, and permit assessment of their threat to the Earth. It would discover and track objects in the Kuiper Belt and monitor a wide variety of variable objects, including the optical afterglow of gamma ray bursts, distant supernovae, and micro-lensing events. By combining data from multiple observations, very deep images could be produced through which it would be possible to infer the structure of dark matter through weak lensing. LSST is seen as an effort that is inherently national in scope. The challenge may not be the design and construction of the telescope or camera, but rather the computing hardware and software that can process the data stream and allow several groups to discover and follow up certain types of objects in real time. NOAO is expected to lead the effort to develop this facility on behalf of the entire community.
The highest medium-size priority of the entire AASC is the Telescope System Instrumentation Program (TSIP). This initiative is a renewal of the Facilities Instrumentation Program (FIP) at the NSF that was established as a result of the McCray Committee report. The FIP funded large instruments for the independent observatories in exchange for telescope time provided by those observatories to the entire community. The TSIP differs in two important ways from the old program. First, its goal is explicitly to foster the development of the system of public and private facilities, and so decisions within it are guided by the system strategic planning that was described above. Second, the exchange rate between funds and telescope time has been cut in half. Half of the funds are seen as support for the independent observatories' improvement of the suite of capabilities, and half are seen as providing broader access to the elements of the system. The TSIP is to be budgeted at $5 million per year. NOAO's participation in this program is closely connected to its role of coordinating the evolution of the system of facilities, as described above.
The highest priority small program recommended by the AASC is the National Virtual Observatory. This initiative, developed by the panel on Theory, Computation, and Data Exploration, involves the integration of all major astronomical archives into a system linked through common standards and interfaces and incorporating powerful tools for data mining. NVO will enable professional astronomers, educators, and the public to take advantage of the huge amount of data from existing and planned surveys (such as LSST). NVO will require coordinated support from both NASA and the NSF, since it will serve both space- and ground-based communities. Although details for the structure and management of the NVO are still being developed, NOAO might well play a role in coordinating efforts on behalf of the ground-based community.