Science imperatives for 2020Chris Carilli NRAONRAO Socorro Science RetreatSocorro, NM, April 10, 2008 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?

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

Historical perspectiveDS2000 (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 basedWhat 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?

EVLA science caseScience 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?

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 + TPActively 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

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 MBH - Mbulge => 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,

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

Cradle of Life: protoplanetary disks on (sub)AU scales + astrobiology + SETICosmic reionization and first light: IGM evolution through HI 21cm line + gas/dust/SF/AGN in first galaxiesDark energy and galaxy evolution: All sky HI (+ continuum) surveyStrong field tests of GR using pulsarsOrigin and evolution of cosmic magnetism: all sky RM surveyKey Science Projects: (i) Address key questions, (ii) Unique role of radio, or complementary but critical, (iii) Excites broad community

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 multibeamingDownside -- still too broad to be practical for one facility

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 experimentsLOFAR -- $100M MWA -- $10MPAPER -- $2M

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

Optical/near-IR Telescope Science PrioritiesThirty meter telescope: Science themes, mostly spectraSpectroscopic exploration of First Light and reionization -- Pop III stars and first galaxiesExploration of galaxies and LSS in young Universe: spectroscopy of galaxy assemblyInvestigation of massive black holes throughout cosmic time: coeval formation gal/BHExploration of planet formation processes and the characterization of extrasolar planets

Optical/near-IR Telescope Science PrioritiesJWST: 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

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 WayOptical/near-IR Telescope Science Priorities

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

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

Common ground and radio contributionsTheme Telescopes Radio role

Galaxy/Black hole evolutionSKA, (ALMA), TMT, JWST, Herschelgas, dust, star form, dynamics, BHsFirst light and reionizationSKA, (ALMA), TMT, JWSTIGM (21cm), gas, dust, star form, dyn, BHsPlanets and proto-planetary disksSKA, (ALMA), TMT, JWSTSub-AU imagingDark energySKA, LSST, ConXVery wide field surveyStar formation(ALMA), JWST, Herschelgas, dustTesting GRSKA, ConX, (LIGO)pulsars

Other Radio DiscussionsRMSPG: Haynes et al. Facility approach Written as radio input to senior review Excellent summary of existing facilitiesChicago 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 surveysWorking groups established: produce WP for DS2010 SKA low (Beasley chair) SKA mid (Lazio/Myers) -- RSST SKA high -- no current WG?

AUI Futures of Radio Astronomy Committee: Chair D. McCrayScience theme approach: Beyond standard model of physics and cosmologyOrigin/evol galaxiesOrigin/evol stars/planets/lifeThe high energy UniverseFundamental and extreme physicsCurrent recommendations (likely to be much revised):Maintain a balanced and vigorous program in RMS science and technology developmentDevelop, test, prototype and implement technologies leading to SKA-class facilitiesNurture partnerships leading to SKA-class facilities

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.

Closing ruminationsALMA Development plan ($10M/yr): science working groups and implementation opportunities provides natural forum for continued advancement of science case and instrumentShould 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

Closing ruminationsVLBA: active staff participation in upgrade planningGBT: clear near-term priorities for instrument development

SKA and DS2010NRAO/AUI has conducted three major forums to determine the way forward for DS2010: Chicago meetings, AUI Futures Committee, Strategic planning retreatsThus far, no clear consensus has been reached in any forum.

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Initial efforts after groningen-- WP review preliminary presented in Groningen, finalized Nov 2002.My impression of revised WPs: very clear on where they meet and fail on compliance matrix, and designs have been massaged to max extent.Makes things easier for decision making: take it or leave it Advantages/disadvantages/ tradeoffs are clear. Now up to ISSC w. input ISAC (science) EMT (technical) to decideBased on science, cost, technical risk factorRevised matrix (Feb 03) was reference matrix for proposers.Matrix called into question, but let stand as standard of reference until revised science case is complete + result of 2 yrs of deliberation. Rawlings will present new matrix + larger issues?

Discussed at length in groningen still stand as significant issues, butrevised WP have been massaged to max => again, makes decisions on designs clearer In groningen started discussion of hybrid designs: low freq w. multibeam, high freq. This has been delineated clearly in EMT review.