Revolutionary discoveries undoubtedly will follow from the realization of the Large Synoptic Survey Telescope (LSST) under construction, the planned 30-meter-class telescopes, and new instrumentation on existing optical and infrared (OIR) telescopes. The challenge is to extract the best science from these and other astronomical facilities in an era of potentially flat federal budgets for both the facilities and the research grants necessary to exploit them. In the 2010s, there is increasing scientific opportunity combined with decreasing purchasing power. This report describes a vision for a nighttime U.S. OIR System that includes a telescope time exchange designed to enhance science return by broadening access to capabilities for a diverse community; an ongoing planning process to identify and construct next-generation capabilities to realize decadal science priorities; and near-term critical coordination, planning, training, and instrumentation needed to usher in the era of LSST and giant telescopes.
The guiding principles used by the National Research Council’s (NRC’s) Committee on a Strategy to Optimize the U.S. Optical and Infrared System in the Era of the Large Synoptic Survey Telescope (LSST) in its deliberations were as follows:
- An integrated OIR System can achieve the best science when it engages a broad population of astronomers to pursue a diversity of science and scientific approaches.
- Federal investment in LSST follow-up capabilities and in community-prioritized instrumentation across the OIR System will help to maximize scientific output.
- Federal support to sustain technology, instrumentation, and software development, and expertise in these fields, is necessary to optimize future science returns.
This report highlights some of the progress on science questions raised by the NRC decadal surveys New Worlds, New Horizons in Astronomy and Astrophysics1 (NWNH) and Vision and Voyages for Planetary Science in the Decade 2013-20222 (VVPS), the existing facilities and capabilities, and the human resources that make up the U.S. OIR astronomical enterprise. The report then considers the science that will be enabled by new instruments and facilities. It highlights the critical OIR instruments that are necessary in the near term to achieve decadal objectives, enable innovative research, and augment LSST with follow-up observations. It then addresses how to optimize scientific return from available resources through cooperation among public and private observatories.
The committee’s top-level recommendations are presented here in priority order, driven by the statement of task (see Preface) and motivated by the guiding principles above. The committee did not have a budget or guidelines for funding; these recommendations are based on science considerations and provided as advice for the National Science Foundation (NSF), the sponsor requesting the report. The accompanying descriptions and justifications for the recommendations are in subsequent chapters.3
The committee’s highest priority is a U.S. OIR System that is well coordinated and facilitates broad access to achieve the best science. Broad access at non-federal telescopes can be accomplished in a number of creative ways, including, but not limited to, engaging in limited term partnerships for partnering on telescopes, instruments, and data; bartering time on one facility for another; and swapping instruments.
RECOMMENDATION 1. The National Science Foundation (NSF) should direct the National Optical Astronomical Observatory to administer a new telescope time exchange with participating observatories of the U.S. Optical and Infrared System. Observatory representatives would barter facilities, swap instruments, or engage in limited term partnerships for telescope time or data access on behalf of their respective constituencies, as appropriate, and NSF would barter telescope time or data access or engage in limited term
1 National Research Council (NRC), 2010, New Worlds, New Horizons in Astronomy and Astrophysics, The National Academies Press, Washington, D.C.
2 NRC, 2011, Vision and Voyages for Planetary Science in the Decade 2013-2022, The National Academies Press, Washington, D.C.
3 For convenience, all of the conclusions and recommendations that appear in individual sections are listed in the Epilogue in order of appearance.
partnerships to carry out proposals competed through a system-wide time allocation committee. (Chapter 6)
Maximum returns from federal investment will be achieved when the community has the capabilities necessary to address the decadal science priorities. Those capabilities include not only existing ones but also new ones that are developed as the science evolves. The decadal surveys identify long-term goals for community facilities, but capabilities needed in the short term, particularly in rapidly evolving areas of research, would benefit from shorter planning timescales. Achieving these capabilities through coordination or partnerships can be accomplished by establishing at the national level an ongoing planning process that will engage the entire OIR user community in identifying and realizing small- and medium-scale projects and programs between decadal and mid-decadal reviews.
RECOMMENDATION 2. The National Science Foundation should direct the National Optical Astronomical Observatory (NOAO) to administer an ongoing community-wide planning process to identify the critical Optical and Infrared System capabilities needed in the near term to realize the decadal science priorities. NOAO could facilitate the meeting of a system organizing committee, chosen to represent all segments of the community, which would produce the prioritized plan. NSF would then solicit, review, and select proposals to meet those capabilities, within available funding. (Chapter 6)
As a start in the OIR System planning, and as charged, the committee has in this report identified a number of instrumentation and coordination requirements that would enhance the science output from medium (3.5- to 5-meter) and large (6- to 12-meter) telescopes, including augmenting LSST data once they come online.
RECOMMENDATION 3. The National Science Foundation should support the development of a wide-field, highly multiplexed spectroscopic capability on a medium- or large-aperture telescope in the Southern Hemisphere to enable a wide variety of science, including follow-up spectroscopy of Large Synoptic Survey Telescope targets. Examples of enabled science are studies of cosmology, galaxy evolution, quasars, and the Milky Way. (Chapter 5)
LSST, the top-ranked, large, ground-based facility recommended in NWNH and highly ranked in VVPS, will enable a broad range of science across the community. The science returns will be even greater through complementary and supplementary work at other facilities. Recommendations 4a-4d target the optimization of science from data obtained with LSST. The large number of transient events that will be detected nightly by LSST will require a software event broker system to identify significant objects that need spectroscopic and higher-cadence photometric follow-up. Coordination of federally supported facilities and capabili-
ties in the Southern Hemisphere will enable a rapid response to these events and therefore promote maximum scientific productivity.
RECOMMENDATION 4a. The National Science Foundation should help to support the development of event brokers, which should use standard formats and protocols, to maximize Large Synoptic Survey Telescope transient survey follow-up work. (Chapter 5)
RECOMMENDATION 4b. The National Science Foundation should work with its partners in Gemini to ensure that Gemini South is well positioned for faint-object spectroscopy early in the era of Large Synoptic Survey Telescope operations, for example, by supporting the construction of a rapidly configurable, high-throughput, moderate-resolution spectrograph with broad wavelength coverage. (Chapter 5)
RECOMMENDATION 4c. The National Science Foundation should ensure via a robustly organized U.S. Optical and Infrared (OIR) System that a fraction of the U.S. OIR System observing time be allocated for rapid, faint transient observations prioritized by a Large Synoptic Survey Telescope event broker system so that high-priority events can be efficiently and rapidly targeted. (Chapter 5)
RECOMMENDATION 4d. The National Science Foundation should direct its managing organizations to enhance coordination among the federal components of medium- to large-aperture telescopes in the Southern Hemisphere, including Gemini South, Blanco, the Southern Astrophysical Research (SOAR) telescope, and the Large Synoptic Survey Telescope (LSST), to optimize LSST follow-up for a range of studies. (Chapter 5)
Looking to the future, it is beneficial for NSF and the community to consider facilities and technologies that will bring the greatest scientific return for the investment. The largest telescopes, the Giant Segmented Mirror Telescopes (GSMTs), are being constructed by private and international partners. It is important for a broad U.S. community to have direct access to the GSMTs through federal investment so that the best science can be achieved.
RECOMMENDATION 5. The National Science Foundation should plan for an investment in one or both Giant Segmented Mirror Telescopes in order to capitalize on these observatories’ exceptional scientific capabilities for the broader astronomical community in the Large Synoptic Survey Telescope era, for example, through shared operations costs, instrument development, or limited term partnerships in telescope or data access or science projects. (Chapter 4)
Many types of technologies are in various stages of development. Adaptive optics (AO), for example, has become a mainstay of telescopes but needs more investment in order for AO-assisted telescopes to achieve the most stable images with the best possible resolution; detector technology continues to improve. Sustaining technological developments and maintaining U.S. expertise in instrumentation and software are important for remaining competitive in the rapidly advancing world stage of OIR astronomy.
RECOMMENDATION 6. The National Science Foundation (NSF) should continue to invest in the development of critical instrument technologies, including detectors, adaptive/active optics, and precision radial velocity measurements. NSF should also use existing instrument and research programs to support small-scale exploratory programs that have the potential to develop transformative technologies. (Chapter 4)
RECOMMENDATION 7. The National Science Foundation (NSF) should support a coordinated suite of schools, workshops, and training networks run by experts to train the future generation of astronomers and maintain instrumentation, software, and data analysis expertise. Some of this training might best be planned as a sequence, with later topics building on earlier ones. NSF should use existing instrument and research programs to support training to build instruments. (Chapter 3)
There are a number of important topics for which the committee has reached conclusions but not recommendations. Among these are conclusions regarding data archives and their public availability and means of access (Section 3.3), the Dark Energy Camera (DECam) and Dark Energy Spectroscopic Instrument (DESI) (Section 5.1), the Mid-Scale Innovations Program (MSIP) structure (Section 6.3), and international discussions (Section 6.5).