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AUI Cooperative Agreement — NSF Panel ReviewAugust 25 – 28, 2008

National Radio Astronomy Observatory

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.

2AUI Cooperative Agreement Proposal NSF Panel ReviewAugust 25 – 28, 2008

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

3AUI Cooperative Agreement Proposal NSF Panel ReviewAugust 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

4AUI Cooperative Agreement Proposal NSF Panel ReviewAugust 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.

5AUI Cooperative Agreement Proposal NSF Panel ReviewAugust 25 – 28, 2008

Key Science Projects: (i) Address critical questions, (ii) Unique role of radio, or

complementary but fundamental, (iii) Excites broad community

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

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

6AUI Cooperative Agreement Proposal NSF Panel ReviewAugust 25 – 28, 2008

Table 1: Science drivers for future large area telescopes

Science theme Telescope Radio role Galaxy/Black hole evolution (KSP II) EVLA, VLBA, GBT, ALMA, TMT,

JWST, Herschel gas, dust, star form, dynamics, BHs

First light and reionization (KSP I)

EVLA, ALMA, TMT, JWST

IGM (21cm), gas, dust, star form, dyn, BHs

Planets and proto-planetary disks (KSP V)

EVLA, ALMA, TMT, JWST

Sub-AU imaging, extrasolar Jupiter bursts

Cosmology: geometry of Universe, dark energy… (KSP II)

VLBA, GBT, LSST, SNAP…

Ho via maser disks, wide field HI surveys

Star formation (KSP V)

EVLA, GBT, ALMA, JWST, Herschel

gas, dust, dynamics, chemistry

Extremes of physics: Testing GR, extreme states of matter, GBRs, XRBs, relativistic jets… (KSP IV)

GBT, EVLA, VLBA, GLAST, ConX, LIGO

Pulsars, magnetars, submas imaging

Multi-wavelength approach to addressing key questions in modern astrophysics

7AUI Cooperative Agreement Proposal NSF Panel ReviewAugust 25 – 28, 2008

Power of radio astronomy

• 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

HST + OVRO CO

VLA polarization

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HST

• SMA 350 GHz detection of proplyds in Orion

• Derive dust mass (>0.01Mo), temperature

KSP V: Protoplanetary disks and planet formation

Williams et al.

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TW Hya Disk: VLA observations of planet formation

Calvet et al. 2002

mid-IR “gap”

cm slope ”pebbles”

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?

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TW Hya Disk: VLA observations of planet formation

Hughes, Wilner +

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

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ALMA 850 GHz, 20mas

Wolfe +

Birth of planets: The ALMA/EVLA revolution

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

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Infrared Dark Clouds (IRDCs)

0.5o

Extinction features seen in silhouette against the Galactic IR background

1,000s seen in the Spitzer GLIMPSE survey (and previous surveys like MSX)

Eg

an

et

al. (

199

8);

Care

y e

t al. (

200

0);

Sm

ith

et

al. (

200

6);

Rath

born

e e

t al.

(200

6);

Pill

ai et

al. (

200

6)

and

many

oth

ers

Sites of the earliest phases of massive star formation

3.6 m 4.5 m 8.0 m

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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

Devin

e e

t 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 +)

D. Backer

Predicted timing residualsPredicted timing residuals

• 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)

Credit: D. Manchester, G. Hobbs

NanoGrav

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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

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Measuring Distances to H2O Megamasers

Two methods to determine distance:

• “Acceleration” method

D = Vr2 / a

• “Proper motion” method

D = Vr / (d/dt)

NGC 4258

2Vr

2

D = r/

a = Vr2/r

D = Vr2/a

Vr

Herrnstein et al. (1999)

D = 7.2 0.5 Mpc

• Recalibrate Cepheid distance scale

• Problem: NGC 4258 is too close

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The Project (Braatz et al.) 1. Identify maser disk galaxies with GBT into Hubble flow ~ 50 currently2. Obtain high-fidelity images of the sub-pc disks with the High

Sensitivity Array (VLBA+GBT+Eff+eVLA) ~ 10% are useful3. Measure internal accelerations with GBT monitoring4. Model maser disk dynamics and determine distance to host galaxy

Goal: 3% measure of Ho

GBT

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UGC 3789: A Maser Disk in the Hubble Flow

Discovery: Braatz & Gugliucci (2008)VLBI imaging: Reid et al. (in prep)Distance/modeling: Braatz et al. (in prep)

Acceleration modeling

D ~ 51 MpcHo = 64(+/-7)

Already at HST Key project accuracy with 1 source!

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Dark Ages

Cosmic Reionization

• 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

KSP I: Cosmic reionization and first (new) light in the Universe

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• Highest redshift SDSS QSO • Lbol = 1e14 Lo

• Black hole: ~3 x 109 Mo (Willot etal.)• Gunn Peterson trough = near edge of reionization (Fan etal.)

Pushing into reionization: QSO 1148+52 at z=6.4 (tuniv = 0.87Gyr)

GP effect => first galaxies/BH are only observable at near IR through radio wavelengths

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• Dust mass ~ 7e8 Mo

• Gas mass ~ 2e10 Mo

• CO size ~ 6 kpcLow order molecular lines redshift to cm

bands = ‘fuel for gal formation’

mm/cm: Gas, Dust, Star Form, in host galaxy of J1148+5251

1” ~ 6kpc

CO3-2 VLA z=6.42

• 30% of z>6 SDSS QSO hosts are HyLIRGs

• Dust formation associated with high mass star formation?

LFIR = 1.2e13 Lo

MAMBO/IRAM 30m

Only direct observations of host galaxy properties

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FIR excess -- follows Radio-FIR correlation: SFR ~ 3000 Mo/yr

CO excitation ~ starburst nucleus: Tkin ~ 100K, nH2 ~ 1e5 cm-3

Radio-FIR correlation

50KElvis QSO SED

Continuum SED and CO excitation: ISM physics at z=6.42

NGC253

MW

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[CII] 158um at z=6.4: dominant ISM gas coolant

[CII] PdBI Walter et al.

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

1”

[CII] + CO 3-2

[CII]

[NII]

IRAM 30m

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Building a giant elliptical galaxy + SMBH at tuniv < 1Gyr

Multi-scale simulation isolating most

massive halo in 3 Gpc^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

10.5

8.1

6.5

Li, Hernquist, Roberston..

z=10

• 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

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(sub)mm: high order molecular lines. fine structure lines -- ISM physics, dynamics

cm telescopes: low order molecular transitions -- total gas mass, dense gas tracers

Pushing to first normal galaxies: spectral lines

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

SMA

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.

, GBTGBT

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cm: Star formation, AGN

(sub)mm Dust, cool gas

Near-IR: Stars, ionized gas, AGN

Arp 220 vs z

Pushing to normal galaxies: continuum

A Panchromatic view of galaxy formation

SMA

GBT

eg. GBT = wide field ‘finder’; ALMA = detailed imager

28AUI Cooperative Agreement Proposal NSF Panel ReviewAugust 25 – 28, 2008

END

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1.4 GHz stacking: 30,000 z~2 ‘normal’ galaxies in COSMOS

Current VLA ~ 40 uJy detections; Stacking => 2 +/- 0.2 uJy

2e10 Mo3e11

Radio-derived

UV-derived (w/o dust corr.)

100 Mo/yr10 Mo/yr

5x

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

Panella etal

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HI 21cm Tomography of IGM

z=14

7.6

SKA: Direct imaging of evolution of neutral IGM

Pathfinders: statistical detection (power spectrum), largest Stromgren spheres, absorption toward first radio AGN

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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

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Destination: Moon! 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++)

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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.

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TW Hya -- Molecular gas

SMA: Gas mass, rotation

ALMA: dynamics at sub-AU, sub-km/s resolution

SMA

ALMA simulation

Wilner