1. 1 NRAO Socorro Science Retreat Socorro, NM, April 10, 2008 Science imperatives for 2020 Chris Carilli NRAO I will not define the science imperatives for NRAO in the next decade. I will present current landscape: science cases in radio, optical…, plus various committee reports. Goal: Science-driven vision for (radio) astronomy in next decade. Where does NRAO fit? How do we approach DS2010?

2. 2 Documents considered Historical perspective -- pre-2020 review Reports: Decadal Survey (McKee/Taylor), Quarks-Cosmos Science goals: EVLA, ALMA Intermezzo: Major advances in astrophysics since DS2000/EVLA Modern era -- post-2020 review Science goals: SKA, JWST, TMT, LSST, Herschel, ConX Reports: RMSPG, AUI-Futures (McCray), Chicago I,II,III Science cases can be: Facility based/Technology driven Theme based Question based Project/experiment based

3. 3 Historical perspective DS2000 (McKee-Taylor) Facility based Broad-brush document -- too much so, unrealistic costing? EVLA, ALMA recommended highly Recommended both User grants and development $$ Quarks-to-Cosmos -- supplanted DS2000? Question based What is dark matter? (HI studies) What is dark energy? (HI surveys) How did Universe begin? (CMB) Did Einstein have last word on gravity? (Pulsars) Neutrino mass and evolution? Cosmic accelerators? (AGN/SNR) Are protons stable? New states of matter at high den/temp? (Neutron stars) Are there extra dimensions? How are elements Fe -- U formed? Is new theory of matter/light needed at highest energies?

4. 4 EVLA science case Science theme based The Magnetic Universe -- obvious radio forte The Obscured Universe -- PPdisks, YSOs, QSO abs lines… The Transient Universe -- GRBs, XRBs, Mdwarfs… The Evolving Universe -- galaxy evolution Question: was the science case generated before or after the technical case?

5. 5 ALMA science: Project based Image molecular gas in z~3 MW-mass galaxies => A/T (64x12m) Image PP disks on AU scales => ~10km baselines @ submm HST quality imaging => # ant, ACA + TP Actively involved/energized User community Continuous refinement of ALMA science case, enabled by, but not dictated by, executives ASAC + regional SACs: eg. organized the DRSP = observing proposals for ALMA from community to gauge ‘demand’ and prioritize use cases Annual regional topical science meetings Regular international ‘love fests’

6. 6 Advances in modern astrophysics since DS00 and EVLA Precision cosmology: few % knowledge of age, mass-energy content of Universe Probing epoch of first light (cosmic reionization) at z >~ 6 GRBs = biggest explosions in Universe, massive star explosions to z ~ 6 M BH - M bulge => all spheroids have BHs with fixed mass ratio. BH and Galaxy evolution are causally connected  Quasars ~ AGN on 1e7 smaller scales double pulsars + Glob Cluster pulsars, gravity waves -- unprecedented labs for tests strong field GR Extrasolar planets -- they are everywhere! Proto-planetary disks: clear signatures of planet formation Kuiper-belt objects -- what is Pluto? Mapping Universe -- SDSS, FIRST, NVSS, COSMOS, UDF, …

7. 7 Three year process run by ISAC Experiment based: Quantified ‘experiments’ for future large area cm telescopes – not just radio astronomy reviews nor root N science 50 chapters, 90 contributing authors, 25% theorists, but minority of multiwavelength observers

8. 8 Cradle of Life: protoplanetary disks on (sub)AU scales + astrobiology + SETI Cosmic reionization and first light: IGM evolution through HI 21cm line + gas/dust/SF/AGN in first galaxies Dark energy and galaxy evolution: All sky HI (+ continuum) survey Strong field tests of GR using pulsars Origin and evolution of cosmic magnetism: all sky RM survey Key Science Projects: (i) Address key questions, (ii) Unique role of radio, or complementary but critical, (iii) Excites broad community

9. 9 All require sensitivity: A/T >= 1e4 m^2/K Most require frequencies >= 10 GHz Many require > 1deg^2 FoV at 1.4 GHz Some require > 1000 km baselines Some require multibeaming Downside -- still too broad to be practical for one facility

10. 10 SKA path-finders (spurred, in part, by SKA science discussions) HI 21cm survey instruments ASKAP (Oz) -- $100M MeerKAT (SA) -- $100M PrepSKA (EU) -- $50M Apertif (WSRT FPA) -- $10M Reionization experiments LOFAR -- $100M MWA -- $10M PAPER -- $2M

11. 11 SKA phased approach Phase I: SKA mid, 0.5 to 3 (or 10?) GHz, 10% collecting area, some long baselines, tile arrays + small dishes, large FoV Phase II: Full SKA mid, plus full SKA low (70 -- 200MHz) Phase III: up to 25GHz -- not specified as to how, or when, to get there (and why 25GHz vs. 45GHz?) Phase I Phase II

12. 12 Optical/near-IR Telescope Science Priorities Thirty meter telescope: Science themes, mostly spectra Spectroscopic exploration of First Light and reionization -- Pop III stars and first galaxies Exploration of galaxies and LSS in young Universe: spectroscopy of galaxy assembly Investigation of massive black holes throughout cosmic time: coeval formation gal/BH Exploration of planet formation processes and the characterization of extrasolar planets

13. 13 Optical/near-IR Telescope Science Priorities JWST: science themes, mostly near-IR imaging + spectra First light and cosmic reionization Assembly of galaxies and black holes Birth of stars and proto-planetary systems: dusty disks in near-IR Planets and the origins of life: imaging extrasolar giant planets + KPOs…

14. 14 LSST: Project based Constraining dark energy and dark matter: very large volume survey Taking an inventory of the solar system Exploring the transient optical sky Mapping the Milky Way Optical/near-IR Telescope Science Priorities

15. 15 Herschel: Science theme based How galaxies formed and evolved in the early universe, and the nature of enormously powerful galactic energy sources. The formation, evolution, and interrelationship of stars and the interstellar medium in the Milky Way and other galaxies. Chemistry in our galaxy. Molecular chemistry in the atmospheres of Mars and our solar system's comets and giant planets, and the nature of comet-like objects in the Kuiper belt beyond Neptune. FIR Space Telescopes

16. 16 Constellation X: Experiment based Black Holes: Using black holes to test General Relativity (GR) and measuring black hole spin Dark Energy: Improving the constraints on the key Dark Energy (DE) parameters by a factor of ten Missing Baryons: Unambiguous detection of the hot phase of the Warm-Hot Intergalactic Medium (WHIM) at z>0 Neutron Star Equation of State: Measuring the mass-radius relation of neutron stars to determine the Equation of State (EOS) of ultra-dense matter Xray Telescopes

17. 17 Common ground and radio contributions Galaxy/Black hole evolution SKA, (ALMA), TMT, JWST, Herschel gas, dust, star form, dynamics, BHs First light and reionization SKA, (ALMA), TMT, JWST IGM (21cm), gas, dust, star form, dyn, BHs Planets and proto- planetary disks SKA, (ALMA), TMT, JWST Sub-AU imaging Dark energySKA, LSST, ConXVery wide field survey Star formation(ALMA), JWST, Herschel gas, dust Testing GRSKA, ConX, (LIGO)pulsars Theme Telescopes Radio role

18. 18 Other Radio Discussions RMSPG: Haynes et al. Facility approach Written as radio input to senior review Excellent summary of existing facilities Chicago I, II, III: NRAO/AUI/NAIC coordinated effort to consider scientific future of radio astronomy, in preparation for DS2010 Engage broader community -- optical, theory, high energy (not connected to SKA) No clear consensus on science, although some support for HI surveys Working groups established: produce WP for DS2010 SKA low (Beasley chair) SKA mid (Lazio/Myers) -- RSST SKA high -- no current WG?

19. 19 AUI Futures of Radio Astronomy Committee: Chair D. McCray Science theme approach: Beyond standard model of physics and cosmology Origin/evol galaxies Origin/evol stars/planets/life The high energy Universe Fundamental and extreme physics Current recommendations (likely to be much revised): Maintain a balanced and vigorous program in RMS science and technology development Develop, test, prototype and implement technologies leading to SKA-class facilities Nurture partnerships leading to SKA-class facilities

20. 20 McCray Summary at Jan08 AAS Ensure proper operation of ALMA, EVLA, GBT: ease of use for non-experts, grants => leverage capital investment Maintain technical development and educational aspects at (some) UROs. Emphasize surveys -- FPAs, wide field imaging. SKA -- stay the course of TDP, not ready for $100M investment. No specific statement on VLBA or Arecibo.

21. 21 Closing ruminations ALMA Development plan ($10M/yr): science working groups and implementation opportunities provides natural forum for continued advancement of science case and instrument Should NRAO secure access to supporting facilities (LMT, CCAT…)? EVLA: re-energize the community (and staff!), led by SAGE Regenerate science case in modern context: phase I, II, III (?) and/or DRSP for EVLA EVLA science meeting(s) Needed if want any chance of getting proper User support $$ Might present path forward for DS2010

22. 22 Closing ruminations VLBA: active staff participation in upgrade planning GBT: clear near-term priorities for instrument development SKA and DS2010 NRAO/AUI has conducted three major forums to determine the way forward for DS2010: Chicago meetings, AUI Futures Committee, Strategic planning retreats Thus far, no clear consensus has been reached in any forum.

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