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National Radio Astronomy ObservatoryNRAO Operations Review ~ February 29 – March 1, 2008

Current and Future Science with NRAO Instruments

Chris Carilli

Four exemplary science programs that demonstrate the synergy between NRAO instruments, and their key roles in modern, multiwavelength astrophysics.

a. First galaxies: gas, dust, star formation into cosmic reionizationb. Cosmic geometry: Megamasers and a 3% measure of Ho

c. Protoplanetary disks: imaging planet formationd. At the extremes of physics: strong field GR, TeV sources

explained!

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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

I. Radio studies of the first galaxies: gas, dust, star formation, into cosmic reionization

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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)

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• Dust mass ~ 7e8 Mo

• Gas mass ~ 2e10 Mo

• CO size ~ 6 kpc

Note: low order molecular lines redshift to cm bands

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? AGB Winds take > 1.4e9yr > age Universe

=> dust formation associated with high mass star formation?

LFIR = 1.2e13 Lo

MAMBO/IRAM 30m

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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.

, GBT

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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

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II. Cosmic geometry: Ho to few % with 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

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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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HST

• SMA 350 GHz detection of proplyds in Orion • Derive dust mass (>0.01Mo), temperature

III. 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:• consistent with disk gap model

• cm probes grains sizes between ISM dust and planetesimals (~1cm)

Dec= -34

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ALMA 850 GHz, 20mas res.

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

• EVLA: AU-scale imaging of large dust grain emission

• JWST: image dust shadow on scales 10’s mas

• Herschel: dust spectroscopy

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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

Credit: Bill Saxton, NRAO

IV. At the extremes of physics

• Extreme gravity: using pulsars to detect nHz gravity waves

• TeV sources: explained by VLBI!

Gravitational Wave Detection using a ‘pulsar timing array’ with NANOGrav (Demorest +)

D. Backer

Predicted timing residualsPredicted timing residuals

• Need ~20-40 MSPs with ~100 ns timing RMS

• bi-weekly, multi-freq 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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Discovered 1976 @ 100 MeV; variable 5 GHz emission.

High mass binary: 12 Mּס Be * , 1–3Mּס NS or BH.

Eccentric orbit e=0.7, period 26.5 days.

X-rays peak @ periastron, radio 0.5 cycle later.

TeV detected by Magic MODELS:

(A) Accretion powered relativistic jet (microQuasar?)

(B) Compact pulsar wind nebula

LS I +61 303: Solving the TeV mystery

> 400 GeV

Xray

Radio

Albert+ 2006

Harrison + 2000

VLBA Images vs. Orbital Phase(orbit exaggerated)

VLBA movie shows 'cometary' morphology => a Pulsar Wind Nebula shaped by the Be star envi-ronment, not a relativistic jet.

Dhawan +

VLBA resolution ~ 2AU

Be

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Gamma-Rays from AGN Jets• GLAST launch

scheduled for May 2008

• VLBA jet imaging on pc-scales during flares required to understand gamma ray production

• Prelaunch survey: VIPS project to image 1100 objects (Taylor et al.)

• Planned: 43 GHz + GLAST monitoring of gamma ray blazars

Marscher et al.

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NRAO in the modern context

Golden age of astrophysics: NRAO telescopes play a fundamental role in topical areas of modern astrophysics• Precision cosmology: setting the baseline (Planck ++)

• Galaxy evolution and first (new) light: gas, dust, star formation (JWST, TMT)

• Birth of stars and planets: dust and gas on AU scales (JWST, Herschel)

• Testing basic physics: GR, fundamental constants, … (LIGO, LISA)

• Resolving high energy phenomena: a ray source primer (GLAST, CONX)

Capabilities into next decade keep NRAO on the cutting edge• ALMA -- biggest single step ever in ground based astronomy

• EVLA -- the premier cm telescope on the planet, and a major step to the SKA

• GBT -- just hitting its stride, with pending FPA revolution

• VLBA -- Mankind’s highest resolution instrument

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END

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Current large programs: VLA, VLBA, GBT

AUI Operations ReviewFebruary 29 – March 1, 2008

• Radio interferometric planet search -- VLBA, VLA, GBT

• Coordinated radio and infrared survey for high mass star formation -- VLA

• Definitive test of star formation theory -- GBT

• Legacy survey of prebiotic molecules toward Sgr B2 and TMC-1 -- GBT

• Detecting nHz gravitational radiation using pulsar timing array -- GBT

• Star Formation History and ISM Feedback in Nearby Galaxies -- VLA

• LITTLE THINGS survey: HI in dwarf galaxies -- VLA

• Megamaser cosmology project -- GBT, VLBA, VLA

• Probing blazars through multi-waveband variability of flux, polarization, and structure -- VLBA

• MOJAVE/GLAST program: mas imaging of gamma ray sources -- VLBA

• VLA low frequency sky survey -- VLA

• Deep 1.4 GHz observations of extended CDFS -- VLA

GR tests: Timing of the Double Pulsar J0737-3039

GBT provides the best timing precision for this system

6 post-Keplerian orbital terms give neutron star masses

strong-field tests of GR to 0.05% accuracy

Measure relativistic spin precession:

Obs = 5.11+/- 0.4 deg/yrGR = 5.07 deg/yr

Kramer et al., 2006, Science, 314, 97