Pathways to Discovery in Astronomy and Astrophysics for the 2020s (2023) / Chapter Skim
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Pages 180-220
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From page 180... ...
The TESS Guest Observer program has also led to time-domain discoveries and follow-up ranging from near-Earth objects such as comets, to eruptions from active galactic nuclei (in concert with NASA's Swift Explorer mission) , to tidal disruption events caused by stars being disrupted by black holes.
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From page 181... ...
However, especially for technical teams at small institutions, this is challenging owing to structural barriers to entry. For instrumentalists and mission leaders (PIs, project scientists, and instrument leads)
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From page 182... ...
These multiple routes for funding mid-scale projects -- MSIP and MSRI -- have different funding streams: MSIP falls within the NSF AST budget, whereas MSRI is NSF-wide. While this increases the diversity of funding opportunities, the total amount of funding available for astronomy and astrophysics projects faces uncertainties owing to the added NSF-wide competition for the latter program.
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From page 183... ...
are C vital to the enabling foundation of astronomy research. As evidenced by the number of compelling community white papers, and given the assessments of the PAG, OIR, RMS, and EFR panels, the survey committee recommends in Chapter 7 expanding the midscale programs, including adding elements that ensure their responsiveness to decadal survey priorities.
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From page 184... ...
. The maximum FRB fluence was assumed to be 500 Jy ms, FIGURE 6.4 Some of the hardware projects supported by the MSIP program between September approximately corresponding to the Lorimer burst (Ravi 2019)
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From page 185... ...
TECHNOLOGY FOUNDATIONS AND SMALL- AND MEDIUM-SCALE SUSTAINING PROGRAMS 185 MAPS LMT Keck Observatory AO Systems BICEP POLARBEAR/Simons Array, ACT, CLASS, and ALMA ACT CMB Detector Array BICEP/Keck and SPIDER CMB Detector Array Telescope Collaboration; HERA Partnership; Keck Planet Finder courtesy of California Institute of Technology; Green Bank Observatory/Associated Universities, Inc.; CHARA -- Steve Golden/Center for High Angular Resolution Astronomy; LLAMAS -- adapted from Furesz et al., 2020, Proceedings of SPIE 11447, Ground-Based and Airborne Instrumentation for Astronomy VIII, 114470A, https://doi.org/10.1117/12.2562803; Evryscope -- Nicholas Law and the Evryscope Collaboration; DSA-10 -- ; MAPS -- Lori Harrison, Center for Astronomical Adaptive Optics, University of Arizona; LMT -- INAOE photo archive; Keck Observatory AO Systems -- Sean Goebel Photography; BICEP -- adapted from Moncelsi et al., 2020, Proceedings of SPIE 11453, Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy X, 1145314, https:// doi.org/10.1117/12.2561995; POLARBEAR/Simons Array, ACT, CLASS, and ALMA -- Debra Kellner/ Brian Bloss; ACT CMB Detector Array -- Li et al., 2016, Proceedings of SPIE 9914, Millimeter, Submillimeter, and FarInfrared Detectors and Instrumentation for Astronomy VIII, 991435, https:// doi.org/10.1117/12.2233470; BICEP/Keck and SPIDER CMB Detector Array -- The BICEP/Keck Collaboration, adapted from Ade et al., 2014, Astrophysical Journal 792:62, https://doi.org/10.1088/0004-637X/792/1/62, © AAS, reproduced with permission.
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From page 186... ...
These science themes reflect that we have entered a new phase of astronomical exploration in multiple dimensions, combining detailed characterization of known classes of objects with opening up the vast discovery space of the unknown. In addition to the broad science themes, the survey committee identified three priority science areas that define the scientific frontiers and motivate the recommended new investments in large projects: Unveiling the Hidden Drivers of Galaxy Growth; New Windows on the Dynamic Universe; and Pathways to Habitable Worlds.
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From page 187... ...
is a powerful strategic mission expected to launch by the end of this year that, among many other things, will reach back in time to observe the first stages in galaxy formation, complementing the survey's focus on unveiling the hidden drivers of galaxy growth more locally. JWST will also characterize the inner parts of other solar systems and the potentially habitable worlds orbiting small M stars, laying the foundation for the Astro2020 program that will extend this to further distances and Sun-like stars.
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From page 188... ...
imaging galaxy halos, neutron stars U.S. contribution to LISA (ESA-led L-class Low-frequency gravitational wave Massive black hole mergers, white dwarf mission)
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From page 189... ...
The most optimistic scenario provided by NASA, adopted as the guidance for this survey, has the budget growing after FY 2025 at approximately 2 percent per year to $2.5 billion in FY 2040 and beyond. For inflating project budget profiles, the analysis uses an inflation rate of 2.7 percent per year, as derived from NASA's new start inflation index for FY 2020.4 NASA's guidance for the most optimistic budget growth (shown by the solid blue line in Figure 7.10, later in this chapter)
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From page 190... ...
Primary among these is that large strategic missions and MREFC-scale observatories must each advance a broad set of Astro2020's priority science questions. The survey committee was also guided by the judgment that the estimated time from inception to science for any recommended project is an important consideration, and it must be based on a schedule analysis and assume optimal, but realistically achievable, budget profiles.
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From page 191... ...
The Next Generation Very Large Array (ngVLA) Great Observatories Mission and Technology Maturation Program • Design, cost trade studies, and prototyping to prepare • Program to co-mature large strategic missions and for construction, which could begin by the end of the technologies.
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From page 192... ...
7.5.1 Advancing NASA's Large Strategic Missions -- The Great Observatories Mission and Technology Maturation Program The richness of the Astro2020 science calls for a broad range of observational capabilities spanning the electromagnetic spectrum. The power of broad wavelength coverage was demonstrated by NASA's Great Observatories, a panchromatic suite of four missions, launched over the course of three decades, that operated with contemporaneous overlap (Figure 7.1, Table 7.3)
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From page 193... ...
hosts our closest example of a supermassive black hole, the CMZ is a labora tory for studying star formation in the centers of galaxies, in starburst galaxies, and in galaxies at the peak of the star formation density, z ~ 1-3 (Kruijssen & Longmore 2013)
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From page 194... ...
onclusion: Establishing a panchromatic suite of observatories over the next 30 years is essential to C address key questions in all three of the survey's priority science themes. The large strategic mission implementations presented to the survey cannot all be built and launched in an optimal time frame given the current designs, available budgets, and approaches to mission development. The universally long development times for the missions in Table 7.4 indicate that general purpose observatories with the full capabilities envisioned by the community will each take 15–20 years to be developed and launched.
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From page 195... ...
This was done to some extent with the Great Observatories, in that both Spitzer and Chandra were significantly rescoped relative to the original concepts presented to the decadal surveys, yet both provided transformative observational advances.9 A rephasing of the mission and technology maturation process, with more significant and coordinated investment prior to a decadal survey recommendation to proceed with mission development, would provide multiple important benefits. This rephasing would recognize the multi-decadal time scales associated with large strategic missions and their associated technology maturation, and would better avoid the negative consequences associated with commencing missions prior to this maturation.10 By investing more in the maturation process, NASA could develop missions to a level where there is significantly more confidence in the costs and requisite cost profiles before seeking congressional approval for the final implementation.
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From page 196... ...
onclusion: Enabling subsequent decadal surveys to recommend mission implementations with suffi C cient knowledge of the feasibility, overall budgetary needs, and time scale requires significant investment toward maturing large strategic mission science, technologies, and architecture in an integrated way. ecommendation: The NASA Astrophysics Division should establish a Great Observatories Mission and R Technology Maturation Program, the purpose of which is to co-develop the science, mission architecture, and technologies for NASA large strategic missions identified as high priority by decadal surveys.
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From page 197... ...
program size forecasts CONTROLS • Decadal priorities and decision rules • Flagship Program Office • SMD Oversight & Senior Program Review FIGURE 7.3 Flow diagram showing the key functions and scope of the Great Observatories (GO) Mission and Technology Maturation Program.
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From page 198... ...
Last, the scientific focus on the co-evolution of black holes and galaxies suggested by the EOS-2 panel is not necessarily the correct one. Rather, the mission maturation program would include trade studies to determine the scientific foci that are consistent with the broad set of the survey's identified science priorities as well as the suggested cost target.
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From page 199... ...
In the past decade, the uncertainty in the number of Earth-sized potentially habitable planets has been reduced by Kepler and other missions, and it is now known that such planets are common. Improved understanding of the complexities of planetary atmospheres lets us identify the spectroscopic measurements needed to assess the signatures of life.
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From page 200... ...
Prime examples include ultraviolet and visible spectroscopy of the circumgalactic halos and the intergalactic medium and of mass flows within and out of galaxies to reveal the workings of cosmic ecosystems in detail and depth for the first time; high-resolution observations of supermassive black holes and their host galaxies locally and over cosmic time; and the construction of stellar fossil histories of the galaxies in the neighborhood of the Milky Way. The nature and effects of dark matter can be addressed by measuring the joint three-dimensional kinematic and dark matter density profiles of dwarf galaxies. These examples all constitute major components on the New Windows on the Dynamic Universe and the Unveiling the Hidden Drivers of Galaxy Growth priority science areas, and they represent only the tip of the iceberg of the impact such a telescope would have.
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From page 201... ...
The best path forward is to have NASA immediately commence aggressive technology development aimed at achieving the goal described above as part of the Great Observatories Mission and Technology Maturation Program. This program would consider and optimize configurations targeted at performance consistent with the target 6 m off-axis aperture as indicated in Figure 7.6.
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From page 202... ...
If mission and technology maturation are successful, as determined by an independent review, implementation should start in the latter part of the decade, with a target launch in the first half of the 2040s. This is an ambitious strategic mission, and while not at the cost scale of LUVOIR, it will still require an investment comparable to HST or JWST.
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From page 203... ...
. Looking to the future, the LISA mission will open enormous discovery space for probing larger-mass black holes, as well as white dwarf binaries, where electromagnetic observations will be equally essential.
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From page 204... ...
Both panels concluded that probe-scale missions offer exceptional scientific opportunities. Missions at this scale would also address the significant gap in cost, capability, and development time scales between Explorers and strategic missions.
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From page 205... ...
, measuring the formation and buildup of galaxies, heavy elements, and interstellar dust from the first galaxies to today, and probing the co-evolution of galaxies and their supermassive black holes across cosmic time. These goals are all central to the broader scientific themes of the survey.
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From page 206... ...
For large strategic missions, the highest priority is for NASA to rapidly establish the Great Observatories Mission and Technology Maturation Program, with the most important element in that category being to commence maturation of the large IR/O/UV mission. The largest budgetary increase associated with the recommended program arises in the latter half of the decade, assuming that the large IR/O/UV mission is technically ready and sufficiently mature to commence detailed design and implementation (see Figure 7.10, below)
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From page 207... ...
ELT program as proposed to the survey is made up of three elements: the Giant Magellan Telescope (GMT) , the Thirty Meter Telescope (TMT)
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From page 208... ...
The impacts of the ELTs for revealing the workings of the cosmic ecosystem promise to be especially powerful. These telescopes alone will have the sensitivity to make spectroscopic measurements of the faintest galaxies, stellar explosions, and black holes detected by JWST; the result of these studies will be a record over cosmic time of the buildup of matter, stars, heavy elements, and the assembly of the galaxies themselves from hundreds of thousands of years after the Big Bang to the present.
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From page 209... ...
, and high-resolution first-generation spectrometers capable of carrying out groundbreaking observations of exoplanets, ancient stars, and the circumgalactic and intergalactic media, key elements of two priority science areas: Pathways to Habitable Worlds and Unveiling the Hidden Drivers of Galaxy Growth. These capabilities are regarded less as competitive advantages than as powerful synergies between complementary facilities that will hasten the advancement of the science frontier objectives highlighted in this survey.
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From page 210... ...
If NSF investment can fund partnership in only one telescope, but both are viable, NSF's investment should factor in complementarity to the ESO ELT, the ability to address the science questions of the Astro2020 survey, and the relative advantages of a larger diameter (D) , which increases the sensitivity ~D2 to D4 (depending on the science application)
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From page 211... ...
Over the past two decades, second- and third-generation ground-based CMB experiments, deployed in Antarctica and Chile, have made significant advances, including detecting lensing B-mode signatures in the CMB and the CMB-galaxy lensing cross power spectrum. The search for the telltale signature of cosmic inflation through its imprint on the B-mode polarization pattern of the CMB has pushed to fainter and fainter levels, disentangling foregrounds, and placing tighter constraints on this primordial signal.
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From page 212... ...
The project would have broad, flexible capabilities and provide science-ready data products accessible to a diverse community of users. Such a facility would advance multiple high-priority science questions from each of the six science panels,15 and open discovery space.
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From page 213... ...
, which is within 5 percent of the RMS panel assessment, and ~20 percent higher than the project estimate. This discrepancy is reasonable given the early stage of development.
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From page 214... ...
This survey provides the following advice for each of the three tracks: 1. Open calls would continue to emphasize innovative ideas in any area of astrophysics over a wide range of project scales and scientific objectives, consistent with the approach taken in the current AST MSIP program.
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From page 215... ...
The guiding principle is that mid-scale investments serve to enhance the capacity of the portfolio of research capabilities to which the community has access. Given the strong endorsement of many projects by the program panels, the analysis performed by the Panel on an Enabling Foundation for Research, the expected endorsement of ground-based solar physics projects by the solar and space physics decadal survey, and the survey's recommendation to add strategic calls to NSF's mid-scale programs, current mid-scale funding levels are inadequate.
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From page 216... ...
The discovery of gravitational waves from merging black holes in 2015 propelled LIGO to its current essential position as a premier observatory for understanding the demographics and astrophysical implications of black holes and for identifying the sources of heavy elements in the universe. These are among the most rapidly advancing areas in modern astrophysics, and future discoveries are likely to bring additional surprises.
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From page 217... ...
The rate of binary neutron star detections will be sufficient to make precise measurements of the Hubble constant through the detection of electromagnetic counterparts. For merging black holes, the signals will be loud enough for precision tests of general relativity, and for nearby neutron star coalescences, tight constraints can be placed on the equation of state of dense material.
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From page 218... ...
However, the survey strongly endorses the central role played by ground-based gravitational wave observatories to many of the survey's high-priority science questions, and urges NSF to invest in a healthy program to develop technologies for future LIGO upgrades and next-generation facilities. In the frontier observatory category, the survey concludes that NSF Physics Division's IceCube-Gen2 neutrino observatory will have impact on several of the priority science questions and has a central role in the New Messengers and New Physics theme, but again it is not directly ranked.
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From page 219... ...
At lower redshifts, its constraints on the expansion history are not expected to improve upon Euclid's, owing to that telescope's much wider sky coverage. As the systematic errors of Euclid, Rubin Observatory, and Roman are different, the three experiments will provide important verification of each other's results; this is particularly important if Euclid finds significant deviations from standard models for dark energy.
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From page 220... ...
, including the Vera Rubin Observatory's Legacy Survey of Space and Time, Euclid, and the Dark Energy Spectroscopic Instrument. As a result of the discovery of gravitational wave sources in 2015, and the burgeoning of time-domain astronomy this decade, Astro2020 identified New Windows on the Dynamic Universe as one of its priority science areas for the coming decades.
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