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National Radio Astronomy Observatory. AUI Cooperative Agreement — NSF Panel Review August 25 – 28, 2008. Science enabled by NRAO facilities into the next decade. Chris Carilli Process: radio astronomy science priorities, and the NRAO Decadal Survey 2010 working group
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National Radio Astronomy Observatory AUI Cooperative Agreement — NSF Panel Review August 25 – 28, 2008 Science enabled by NRAO facilities into the next decade Chris Carilli Process: radio astronomy science priorities, and the NRAO Decadal Survey 2010 working group Five exemplary science programs that demonstrate the synergy between NRAO instruments, and their key roles in modern, multi-wavelength astrophysics.
Gauging the community • NRAO/AUI has co-sponsored an extensive series of meetings, advisory committees, and internal discussions, to consider the main science priorities for (radio) astronomy into the next decade: • Chicago I, II, III: open meetings with broad, multiwavelength input • NRAO 50th anniversary science meeting • NRAO scientific staff retreats • NRAO strategic planning retreats • GBT, ALMA science workshops • AAS townhall discussions • McCray committee AUI Cooperative Agreement Proposal NSF Panel Review August 25 – 28, 2008
Decade Survey 2010 Working Group • Review reports and produce set of key science programs for radio astronomy in the next decade, delineating the role of NRAO facilities in enabling these programs. • Generate flow-down from science requirements to technical improvements to NRAO facilities, or new facilities, including assessment of technical readiness, (rational) costing, global context (OTC, OSC…) • Goal: Report on role of NRAO in DS2010 for review by user community • Guiding principles • Attract the broad community: multi-wavelength approach to tackling the key problems in modern astronomy • NRAO as a ‘single facility’: complementary use of NRAO facilities to produce non-linear gains in scientific discovery AUI Cooperative Agreement Proposal NSF Panel Review August 25 – 28, 2008
DS2010 Working Group: Initial deliberations • Science priorities expressed in various venues are generally consistent with the Key Science Projects proposed by the SKA science working group in 2004. • [Even SKA project office admits full SKA is not realizable in next decade.] • Near term: Narrow focus to quantify how NRAO facilities will make major strides in addressing the SKA KSP goals, as well as delineate the requisite upgrades, or development work on plausible new facilities. • Naturally places NRAO DS2010 science planning into global context, with firm-footing based on broad community input. AUI Cooperative Agreement Proposal NSF Panel Review August 25 – 28, 2008
Key Science Projects: (i) Address critical questions, (ii) Unique role of radio, or complementary but fundamental, (iii) Excites broad community • JWST primary science goals: • The end of the dark ages: first light and reionization • The assembly of galaxies and SMBH • The birth of stars and proto-planetary systems • Planets and the origins of life I. Cosmic reionization and first (new) light: (i) HI 21cm tomography of IGM, (ii) gas, dust, star formation in first galaxies II. Galaxy evolution and cosmology (BAO): all-sky HI + continuum survey III. Cosmic magnetism -- origin and evolution: all sky RM survey IV. Strong field tests of GR using pulsars V. Cradle of Life: star and planet formation, astrochemistry/biology, SETI AUI Cooperative Agreement Proposal NSF Panel Review August 25 – 28, 2008
Multi-wavelength approach to addressing key questions in modern astrophysics AUI Cooperative Agreement Proposal NSF Panel Review August 25 – 28, 2008
Power of radio astronomy HST + OVRO CO • Seeing through dust: earliest phases of star and galaxy formation • Cool universe: thermal emission from gas, dust = fuel for star and galaxy formation • as astrometry • sub-mas imaging • m/s velocity resolution • Accurate polarimetry -- magnetic fields on all scales • Chemistry and bio-tracers VLA polarization AUI Cooperative Agreement Proposal NSF Panel Review August 25 – 28, 2008
KSP V: Protoplanetary disks and planet formation • SMA 350 GHz detection of proplyds in Orion • Derive dust mass (>0.01Mo), temperature HST Williams et al.
TW Hya Disk: VLA observations of planet formation • Pre-solar nebula analog • 50pc distance • star mass = 0.8Mo • Age = 5 -- 10 Myr • mid IR deficit => disk gap caused by large planet formation at ~ 4AU? Calvet et al. 2002 mid-IR “gap” cm slope ”pebbles”
TW Hya Disk: VLA observations of planet formation • VLA imaging on AU-scales: • cm probes grains sizes between ISM dust and planetesimals (~1cm) • Double-peak morphology is consistent with disk gap model Dec= -34 Hughes, Wilner +
Birth of planets: The ALMA/EVLA revolution ALMA 850 GHz, 20mas Wolfe + Radius = 5AU = 0.1” at 50pc Mass ratio = 0.5MJup /1.0 Msun Wilner • ALMA: AU-scale imaging of dust, gas, unhindered by opacity, nor confused by the central star, on 10mas scale -- secular changes on yearly timescales • EVLA: AU-scale imaging of large dust grain emission (PT link gives fact 2 improvement in resolution) • JWST: image dust shadow on scales 40 mas • Herschel: dust spectroscopy
Egan et al. (1998); Carey et al. (2000); Smith et al. (2006); Rathborne et al. (2006); Pillai et al. (2006) and many others • Extinction features seen in silhouette against the Galactic IR background • 1,000s seen in the Spitzer GLIMPSE survey (and previous surveys like MSX) Infrared Dark Clouds (IRDCs) 3.6 mm4.5 mm8.0 mm 0.5o Sites of the earliest phases of massive star formation
Mapping the Galactic Web of Dense Molecular Gas in IRDCs: Initial Conditions of Massive Star Formation VLA 3-pointing NH3 mosaic • Velocity => distance • Dense gas tracer: physical conditions, chemical evolution • Many hours observing: not an efficient way to survey Devine et al. in 2’ • GBT 1.3 cm heterodyne focal plane arrays • large area mapping of NH3 ~ GLIMPSE essential to understand the initial conditions of massive star formation
KSP IV: Gravitational wave detection using a ‘pulsar timing array’ (NANOGrav, Demorest +) • Need ~20-40 MSPs with ~100 ns timing RMS • bi-weekly obs for 5-10 years • Timing precision depends on • - sensitivity (G/Tsys) (i.e. GBT and Arecibo) • - optimal instrumentation (GUPPI -- wideband pulsar BE) Predicted timing residuals Predicted timing residuals D. Backer
NanoGrav Credit: D. Manchester, G. Hobbs
KSP II: Cosmology -- measure Ho to few % with extragalactic water maser disks.Why do we need an accurate measure of Ho? To make full use of 1% measures of cosmological parameters via Planck-CMB studies requires 1% measure of Ho -- covariance! with Ho constraint
Measuring Distances to H2O Megamasers NGC 4258 Two methods to determine distance: • “Acceleration” method D = Vr2 / a • “Proper motion” method D = Vr / (d/dt) Vr D = r/ 2Vr 2 a = Vr2/r D = Vr2/a Herrnstein et al. (1999) • Recalibrate Cepheid distance scale • Problem: NGC 4258 is too close D = 7.2 0.5 Mpc
The Project (Braatz et al.) Identify maser disk galaxies with GBT into Hubble flow ~ 50 currently Obtain high-fidelity images of the sub-pc disks with the High Sensitivity Array (VLBA+GBT+Eff+eVLA) ~ 10% are useful Measure internal accelerations with GBT monitoring Model maser disk dynamics and determine distance to host galaxy GBT Goal: 3% measure of Ho
UGC 3789: A Maser Disk in the Hubble Flow Acceleration modeling D ~ 51 Mpc Ho= 64 (+/-7) Already at HST Key project accuracy with 1 source! Discovery: Braatz & Gugliucci (2008) VLBI imaging: Reid et al. (in prep) Distance/modeling: Braatz et al. (in prep)
KSP I: Cosmic reionization and first (new) light in the Universe Dark Ages • Major science driver for all future large area telescopes • Last phase of cosmic evolution to be tested • Bench-mark in cosmic structure formation indicating the first luminous sources Radio astronomy role • Gas, dust, star formation, in first galaxies • HI 21cm ‘tomographic imaging’ of neutral IGM Cosmic Reionization
Pushing into reionization: QSO 1148+52 at z=6.4 (tuniv = 0.87Gyr) • Highest redshift SDSS QSO • Lbol = 1e14 Lo • Black hole: ~3 x 109 Mo (Willot etal.) • Gunn Peterson trough = near edge of reionization (Fan etal.) GP effect => first galaxies/BH are only observable at near IR through radio wavelengths
mm/cm: Gas, Dust, Star Form, in host galaxy of J1148+5251 CO3-2 VLA z=6.42 MAMBO/IRAM 30m LFIR = 1.2e13 Lo 1” ~ 6kpc • 30% of z>6 SDSS QSO hosts are HyLIRGs • Dust formation associated with high mass star formation? • Dust mass ~ 7e8 Mo • Gas mass ~ 2e10 Mo • CO size ~ 6 kpc • Low order molecular lines redshift to cm bands = ‘fuel for gal formation’ Only direct observations of host galaxy properties
Continuum SED and CO excitation: ISM physics at z=6.42 Elvis QSO SED 50K NGC253 Radio-FIR correlation MW • FIR excess -- follows Radio-FIR correlation: SFR ~ 3000 Mo/yr • CO excitation ~ starburst nucleus: Tkin ~ 100K, nH2 ~ 1e5 cm-3
[CII] 158um at z=6.4: dominant ISM gas coolant IRAM 30m • z>4 => FS lines redshift to mm band • L[CII] = 4x109 Lo (L[NII] < 0.1 L[CII]) • [CII] similar extension as molecular gas ~ 6kpc => distributed star formation • SFR ~ 6.5e-6 L[CII] ~ 3000 Mo/yr [CII] [NII] 1” [CII] PdBI Walter et al. [CII] + CO 3-2
Building a giant elliptical galaxy + SMBH at tuniv < 1Gyr z=10 10.5 • Multi-scale simulation isolating most massive halo in 3Gpc^3 (co-mov) • Stellar mass ~ 1e12 Mo forms in series (7) of major, gas rich mergers from z~14, with SFR ~ 1e3 - 1e4 Mo/yr • SMBH of ~ 2e9 Mo forms via Eddington-limited accretion + mergers • Evolves into giant elliptical galaxy in massive cluster (3e15 Mo) by z=0 Li, Hernquist, Roberston.. 8.1 6.5 • Rapid enrichment of metals, dust, molecules • Rare, extreme mass objects: ~ 100 SDSS z~6 QSOs on entire sky • Integration times of hours to days to detect HyLIGRs
SMA Pushing to first normal galaxies: spectral lines cm telescopes: low order molecular transitions -- total gas mass, dense gas tracers GBT , GBT (sub)mm: high order molecular lines. fine structure lines -- ISM physics, dynamics • FS lines will be workhorse lines in the study of the first galaxies with ALMA. • Study of molecular gas in first galaxies will be done primarily with cm telescopes ALMA will detect dust, molecular and FS lines in ~ 1 hr in ‘normal’ galaxies (SFR ~ 10 Mo/yr = LBGs, LAEs) at z ~ 6, and derive z directly from mm lines.
Pushing to normal galaxies: continuum A Panchromatic view of galaxy formation Arp 220 vs z SMA cm: Star formation, AGN GBT (sub)mm Dust, cool gas Near-IR: Stars, ionized gas, AGN eg. GBT = wide field ‘finder’; ALMA = detailed imager
END AUI Cooperative Agreement Proposal NSF Panel Review August 25 – 28, 2008
1.4 GHz stacking: 30,000 z~2 ‘normal’ galaxies in COSMOS Current VLA ~ 40 uJy detections; Stacking => 2 +/- 0.2 uJy 3e11 2e10 Mo Specific star formation rate = SFR/M* vs. stellar mass • Radio: no dust-bias, SSFR ~ constant w. M* => ‘universality of SF in galaxies’ • <UVextinction> ~ 5x, but strong trend with SFR (or M*): key to understanding star form history of Universe EVLA will detect (individually) 100’s of normal star forming galaxies at high redshift in every deep field at 1.4 GHz Radio-derived 5x UV-derived (w/o dust corr.) 10 Mo/yr 100 Mo/yr Panella etal
HI 21cm Tomography of IGM z=14 • SKA: Direct imaging of evolution of neutral IGM • Pathfinders: statistical detection (power spectrum), largest Stromgren spheres, absorption toward first radio AGN 7.6
Experiments under-way: pathfinders 1% to 10% SKA MWA (MIT/CfA/ANU) • NRAO participates on individual basis in path-finders • NRAO has world-leading expertise in low freq H/W and S/W, and is developing critical wide field imaging software for LWA, EVLA -- additional resources could benefit all experiments • NRAO has interest in contributing to development of, and potentially operating, next-gen experiment, perhaps parallel mode to FASR project
Low frequency array on far side of Moon by 2025 • No interference • No ionosphere NASA’s top astronomy priority for Presidential initiative to return Man to Moon 2008 NASA Lunar Science Institute: Mission concept study (Colorado, NRL, NRAO, MIT++) Destination: Moon!
RIPL Radio Interferometric Planet Search • Detect Jupiter mass planets around nearby low mass stars through astrometric wobble • 32 stars • M1 – M8 • D = 2.7 – 9.5 pc • 11 are members of known binary or multiple systems • 12 epochs/star/3 years • VLBA + GBT • 512 Mb/s • 1392 hours total Bower et al.
TW Hya -- Molecular gas SMA: Gas mass, rotation ALMA: dynamics at sub-AU, sub-km/s resolution SMA ALMA simulation Wilner