New Worlds, New Horizons in Astronomy and Astrophysics (2010) / Chapter Skim
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From page 183... ...
. They also discuss workforce development and other core activities, the changes in the base program that are prerequisites for substantial new initiatives, and the need to keep existing facilities in balance with the development of new ones (Chapters 5 and 6)
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appointed by the National Research Council (NRC) to assist the committee, namely: • Cosmology and Fundamental Physics, • The Galactic Neighborhood, • Galaxies Across Cosmic Time, • Planetary Systems and Star Formation, and • Stars and Stellar Evolution.
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-- activities funded largely by NSF and private entities, some with a DOE component; • Particle Astrophysics and Gravitation (PAG) -- activities funded by NASA, NSF, and DOE; and • Radio, Millimeter, and Submillimeter Astronomy from the Ground (RMS)
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From page 186... ...
process. The six committee meetings -- including the "Jamboree" meeting involving all four 7_10073_ AstroProcessFlowFigure_Final.eps chairs, the 7-1_1025Program Prioritization Panels, the Infrastructure Study Group Science Frontiers Panel chairs, and the survey committee -- held at key process milestones are indi cated by the orange diamonds.
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From page 187... ...
Although the NASA Astrophysics Division's annual budget has been as high as $1.7 billion in the past,4 it is currently approximately $1.1 billion and projected to remain flat in real-year dollars through 2015, according to the President's FY2011 budget, and to remain flat thereafter according to NASA input to the committee. This implies a decrease in purchasing power over the decade at the rate of inflation.
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From page 188... ...
7 The HEPAP-PASAG report concluded that after allowance for a direct-detection dark matter program -- which is not within the purview of this survey -- Scenario A did not provide enough resources to support major hardware contributions to either LSST or JDEM (U.S. Department of Energy, Report of the HEPAP Particle Astrophysics Scientific Assessment Group (PASAG)
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From page 189... ...
The committee concluded that the way to optimize and consolidate the science return with the resources available is to focus on three broad science objectives for the decade -- targets that capture the current excitement and scientific readiness of the field, and are motivated by the technical readiness of the instruments and telescopes required to pursue the science. These targets -- Cosmic Dawn: Searching for the First Stars, Galaxies, and Black Holes; New Worlds: Seeking Nearby, Habitable Planets; and the Physics of the Universe: Understanding Scientific Principles -- are the drivers of the priority rankings of new activities and programs identified below.
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From page 190... ...
The era when the strong ultraviolet radiation from the first stars ionizes the surrounding hydrogen atoms into protons and electrons is known as the epoch of reionization, which can be studied directly using sensitive radio telescopes. These should determine when reionization occurred, and they would inform the design of a proposed new telescope that would measure how the cavities of ionized hydrogen created by the light from the first generations of stars, galaxies, and black holes expand into the surrounding gas.
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The proposed Laser Interferometer Space Antenna (LISA) mission will search for the signatures of these processes by scanning the skies for the bursts of gravitational waves produced during these early mergers when the black holes are relatively small.
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• Employ LISA to measure the rate at which young galaxies merge through observing powerful bursts of gravitational radiation produced during the coalescence of their nuclear black holes. • Study the oldest stars in nearby galaxies using GSMT.
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realIzInG oPPortunItIes tHe ence of planets is inferred8 through the tiny deflections that they impose on passing light rays from background stars. A survey for such events is one of the two main tasks of the proposed WFIRST satellite.
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In addition, enhancements to NASA Suborbital and Explorer programs could provide testbeds for the development of occulter techniques such as the use of star shades and coronagraphy, which are both immature, and technology development of astrometry and interferometry from space, so as to set the stage for an ambitious direct-detection mission in the 2020s. The scientific contributions and technology development in these various areas are described in detail elsewhere.9 The culmination of the quest for nearby, habitable planets is a dedicated space mission.
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Although the case is compelling for technology development for a future space mission beginning early, its emphasis may shift as new discoveries from the ground and space materialize. If progress is sufficiently rapid by mid-decade, then a decadal survey implementation advisory committee (as discussed in Chapter 3)
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However, these tests have been restricted to the situations where gravity is weak, and the strong field expression of the theory still remains to be tested. The discovery of dark energy and dark matter and the amassed evidence that is at least consistent with the predictions of the theory of inflation present two more examples where carefully controlled astronomical measurements contribute to current understanding of fundamental physics.
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What has become clear over the past few years is that instead of just considering dark energy in different regimes, LSST and WFIRST will actually be quite synergistic, and observations from one are essential to interpreting the results of the other. In particular, by working together, they would provide the powerful color information needed for redshift11 estimation.
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could determine whether a technology development program should be initiated with a view to flying a space microwave background mission during the following decade that would be capable of improving the accuracy by a further factor of 10 and elucidating the physical conditions at the end of inflation. Third, an inescapable consequence of general relativity is the existence of black holes.
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From page 199... ...
We should also witness the capture of stars by massive black holes with signals of such long duration and fidelity that the space-time of the black hole can be directly mapped. In summary, this survey recommends supplementing the current ability to use the universe as a giant cosmic laboratory to study dark energy, inflation, and black holes.
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• Observe x rays from gas orbiting close to the event horizon of black holes using IXO and relativistic jets produced by black holes using ACTA. • Gather indirect evidence using ACTA to show that dark matter comprises a new type of elementary particle by detecting the gamma rays it may emit.
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The broadly based and balanced suite of facili ties that are recommended is flexible and resilient enough to make and exploit the many unanticipated and thrilling discoveries that are sure to come during the coming decade. Many of the most fundamental advances in astronomy and astrophysics have resulted from theoretical discoveries that could not have been anticipated in any planning exercise -- the theory of inflation is one example -- but the recommended Theoretical and Computational Network program and augmentations in individual investigator grants programs at NSF and NASA will help to enable such discoveries.
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Complementary studies of the young stars spawned in these molecular regions will require infrared surveys with high angular resolution both in our galaxy and in the neighboring galaxies the Magellanic Clouds, using JWST in space and GSMT equipped with adaptive optics on the ground. Since solar flares create many cosmic rays that can cause mutations of genetic material, understanding these flares is important for understanding the chances of a planet being habitable.
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These stars are thought to be the main agents for injecting mass and energy into the interstellar medium and for driving galactic outflows. They do this through powerful stellar winds and supernova explosions, both of which are also responsible for accelerating cosmic rays and amplifying magnetic fields.
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However, it is also possible that they will be identified indirectly by the gamma rays that are produced through annihilation or decay processes in distant dark matter con centrations. A new ACTA would be roughly 10 times more sensitive than existing facilities and able to further constrain the nature of dark matter.
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In addition, WFIRST's surveys will address issues central to understanding how galaxies, stars, and black holes evolve. WFIRST will carry out a powerful extrasolar planet search by monitoring a large sample of stars in the central bulge of the Milky Way for small deviations in brightness due to microlensing by intervening solar systems.
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WFIRST will also offer a guest investigator program supporting both key projects and archival studies to address a broad range of astrophysical research topics. WFIRST is a 1.5-meter telescope that will orbit the second Lagrange point (L2)
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The powerful astronomical survey data collected during all of the large-area surveys would be utilized to address a broader range of science through a funded investigator program. An extended mission, subject to the usual senior review process, could both improve the statistical results for the main science drivers and broaden the general investigator program.
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. Explorer Program The Explorer program's Small Explorer (SMEX)
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The placement of this recommendation in the large category reflects the decade's total cost of the program including the augmentation and the committee's view that expanding the Explorer program is essential to maintaining the breadth and vitality of NASA's astrophysics program. This is especially true in an era where budgetary constraints limit the number of flagship missions that can be started.
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: (1) WMaP MIDeX -- NaSa/WMaP Science Team; (2)
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realIzInG oPPortunItIes tHe FIGURe 7.4 Continued.
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SOURCe: detail of large Nd:YaG operating at a wavelength of NaSa. LISA has been studied for more than 20 years and was recommended by the 2001 decadal survey of astronomy and astrophysics and also by two other NRC reports.16 It is a partnership between ESA and NASA that relies on the expertise of both agencies and scientific communities.
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temperatures reach tens of millions Kelvin. Studying the hot component of the universe is central to understanding how galaxies and larger-scale structures form and how energy and matter cycle through galaxies and the circumgalactic medium, and to probing the observable matter closest to black holes and neutron stars.
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For IXO to be ready for a mission start, technology readiness must have progressed to the point that a down-select for the mirror technology can be made and cost uncertainties are reduced. The committee considers that in the current budget climate, allowing any major mission to exceed $2 billion in total cost to NASA would unacceptably imbalance NASA's astrophysics program.
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Descopes should be considered to ensure that the cost to NASA remains below $2 billion but reviewed to ensure that the baseline science requirements are still achieved. Investing 10 percent of NASA's eventual cost is consistent with the committee's other recommendations regarding mission-specific technology development.
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It is currently difficult to anticipate the developments that could justify initiating this mission-specific development program, and the committee therefore recommends that a decadal survey implementation advisory committee be convened mid-decade to review progress both scientifically and technically to determine the way forward, and in particular whether an increased level of support associated with mission-specific technology development should commence. In this case a notional decadal budget of $100 million is proposed.
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Progress in measuring both the polarization and the fine-scale anisotropy of the cosmic microwave background radiation is proceeding rapidly with ground-based telescopes in Antarctica and Chile and space-based instruments. The recommended enhanced Suborbital program, as described below, as well as Missions of Opportunity made possible by an augmented Explorer program, will provide opportunities for substantive balloon experiments to probe the polarization signal to faint levels.
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U.S. Contribution to the JAXA-ESA SPICA Mission The tremendous success of the Spitzer Space Telescope has spurred the development of a yet-more-powerful mid- and far-infrared mission, the Japanese led SPICA mission.
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Topics that are central 19 See for example the following National Research Council reports: An Enabling Foundation for NASA's Earth and Space Science Missions (2009) , A Performance Assessment of NASA's Astrophysics Program (2007)
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With these improvements in spectroscopic capabilities in the submillimeter, infrared, and X-ray regions, ex tracting quantitative information will in many cases become limited by available knowledge of atomic and molecular transition data and cross sections. Further, detailed understanding of magnetized plasmas, the formation of molecules, and complex chemical reactions at a level that can only be obtained experimentally is of central importance to interpreting data from these missions.
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Suborbital Program NASA-supported balloon and rocket experiments, known collectively as the Suborbital program, enable science, develop technology, and provide an invaluable training ground (Figure 7.7)
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These are of a scale inconsistent with the funding levels of the individual investigator grants currently supported by NASA's Astrophysics Theory Program. Examples of particular urgency include cosmological simulations of large-scale structure formation, modeling of galactic flows and feedback, and the general relativistic simulations of physical processes associated with the mergers of neutron stars.
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From page 223... ...
LSST's dark energy program centers on using weak gravitational lensing to constrain the rate of growth of large-scale structure, as well as detecting supernova explosions. For these studies LSST's data are an essential complement to the nearinfrared measurements performed by WFIRST from space.
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The technical risk of LSST as determined by the survey's cost appraisal and technical evaluation (CATE) process was rated as medium low.
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agencies -- the committee recommends two-thirds of the federal share of operations costs be borne by NSF and one-third by DOE. It is recommended that any extended mission should only happen following a successful senior review.
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Indeed, such a program in NSF-AST could take on some of the larger Advanced Technologies and Instrumentation (ATI) projects, so that ATI would emphasize advanced technology development together with instrumenta tion below ~$2 million.
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Next Generation adaptive Optics enable near-infrared and visible wavelength Middle and Upper Systems imaging and spectroscopy at spatial resolution better than that of HST to address a broad science program from exoplanet studies to galaxy formation. North american Nanohertz Detect gravitational waves from the early Upper Observatory for Gravitational Waves universe through pulsar timing.
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They would also be able to study the reflected infrared emission of planets in the habitable zone. The ability of a GSMT to perform direct spectroscopy on very faint galaxies would be crucial in efforts to elucidate the properties of dark matter and merging black holes.
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In the case of GSMT this means coordination with ESO on technology development and instrument selection to create a global system of GSMTs with optimal complementary and scientific reach. The committee notes that public time on a GSMT would, in principle, be subject to the open skies policy in effect for all federally supported U.S.
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Upper: The Giant Magellan Telescope is a 25-meter-class telescope comprising seven 8.4-meter subapertures, one of which is already undergoing polishing. laser tomography will provide adaptive optics correction in small fields over much of the sky, and correction for ground-level seeing will be incorporated over large fields.
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For the operations phase, in the optimistic budget 23 Institutional members as of May 2010 were, for GMT, Astronomy Australia Limited, the Australian National Observatory, Carnegie Institution for Science, Harvard University, Korea Astronomy and Space Science Institute, Smithsonian Astrophysical Observatory, Texas A&M University, the University of Texas at Austin, and the University of Arizona, and for TMT were the Association of Canadian Universities for Research in Astronomy, California Institute of Technology, and the University of California.
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facility VERITAS in Arizona, have discovered 100 sources. These include active galactic nuclei, pulsars, supernova remnants, and binary stars.
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was evaluated by the survey and the total cost, estimated to exceed $400 million, was considered too expensive to be entertained, despite technical risk being medium low. The European Čerenkov Telescope Array (CTA)
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This funding amount, as well as a potential NSF contribution to operations at the requested level of $7.5 million, is contingent on an arrange ment being negotiated that allows broad U.S. astronomical community access to survey products and competed observing time on a facility that should significantly enhance the U.S.
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Collected here is an unranked list of the five components for which increases in funding are deemed most needed. Programs that are not mentioned are assumed to proceed with existing budgets, subject to senior review recommendations, although the committee emphasizes , though the importance of many small elements of the core research programs described elements in Chapter 5.
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Astronomy and Astrophysics Research Grants Program Competed individual investigator grants, as described in Chapter 5, provide critical support for astronomers to conduct the research for which the observato ries and instruments are built. The current funding level has fluctuated, especially because of the welcome injection of ARRA funding, but the rough baseline is $46 million per year.
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From page 237... ...
In round numbers, $3.7 billion is available for new initiatives and augmentations to existing programs within the 2012-2021 budget submissions. As indicated by the example shown in Figure 7.12, it is possible to accommodate the recommended program within the profile, launching WFIRST by the end of the decade; enhancing the Explorer program; getting a good start on LISA; carrying out the IXO, New Worlds, and Inflation Probe technology development programs; making essential augmentations to the core research program; and contributing to SPICA.
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The third priority is to pursue the CMB Technology Development Program, as recommended, to mid-decade review by a decadal survey implementation advisory committee. It is unfortunate that this reduced budget scenario would not permit participation in the JAXA-SPICA mis sion unless that mission's development phase is delayed.
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In the event that the realized budget is closer to an extrapolation of the president's FY2011 budget, that is, between the optimistic budget-doubling and the pessimistic flat-budget scenarios, the order of priority is to phase in the recommended core research program augmentations and the Mid-Scale Innovations Program together and at as fast a rate as the budget will allow, noting that the recommended Gemini augmentation is time-critical. LSST would receive an MREFC start and require NSF-AST operations funding beginning in 2016.
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The scientific opportunities are without precedent -- finding and characterizing other planets like Earth, tracing the history of the cosmos from the time of inflation to our own galaxy and solar system today, detecting the collisions of black holes across the universe, and testing the implications of Einstein's theories a century after they were formulated. The tools are becoming available to make giant strides toward deciphering the mysteries of the two primary components of the cosmos -- dark energy and dark matter -- and
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The profiles and budget costs will vary on a project-by-project and program-by-program basis and should not be taken as representing a literal recommended program. The sandcharts are presented here to show, as an existence proof, that within a "doubling" budget over the decade the astro2010-recommended new initiatives and program augmentations are implementable within DOe High energy Physics spending limits.
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new worlds, new HorIzons astronoMy astroPHysIcs In and The committee has been strategic in its thinking, crafting a program that optimizes the scientific return, building on previous public investment in astrophysics while making difficult choices in laying a foundation for the next decade. The committee notes the unprecedented level of effort and involvement in this survey by the astronomical community, with hundreds of astronomers and astro physicists attending town hall meetings, contributing white papers, and serving on panels.
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