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Current and Future Science with NRAO Instruments

National Radio Astronomy Observatory. NRAO Operations Review ~ February 29 – March 1, 2008. Current and Future Science with NRAO Instruments. Four exemplary science programs that demonstrate the synergy between NRAO instruments, and their key roles in modern, multiwavelength astrophysics.

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Current and Future Science with NRAO Instruments

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  1. National Radio Astronomy Observatory NRAO Operations Review ~ February 29 – March 1, 2008 Current and Future Science with NRAO Instruments Four exemplary science programs that demonstrate the synergy between NRAO instruments, and their key roles in modern, multiwavelength astrophysics. First galaxies: gas, dust, star formation into cosmic reionization Cosmic geometry: Megamasers and a 3% measure of Ho Protoplanetary disks: imaging planet formation At the extremes of physics: strong field GR, TeV sources explained! Chris Carilli

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

  3. 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.)

  4. 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? AGB Winds take > 1.4e9yr > age Universe • => dust formation associated with high mass star formation? • Dust mass ~ 7e8 Mo • Gas mass ~ 2e10 Mo • CO size ~ 6 kpc • Note: low order molecular lines redshift to cm bands

  5. 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

  6. [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

  7. 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

  8. SMA Pushing to first normal galaxies: spectral lines cm telescopes: low order molecular transitions -- total gas mass, dense gas tracers , 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.

  9. Pushing to normal galaxies: continuum A Panchromatic view of galaxy formation Arp 220 vs z SMA cm: Star formation, AGN (sub)mm Dust, cool gas Near-IR: Stars, ionized gas, AGN

  10. 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

  11. 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

  12. 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

  13. 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)

  14. III. Protoplanetary disks and planet formation • SMA 350 GHz detection of proplyds in Orion • Derive dust mass (>0.01Mo), temperature HST Williams et al.

  15. 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”

  16. TW Hya Disk: VLA observations of planet formation • VLA imaging on AU-scales: • consistent with disk gap model • cm probes grains sizes between ISM dust and planetesimals (~1cm) Dec= -34 Hughes, Wilner +

  17. Birth of planets: The ALMA/EVLA revolution ALMA 850 GHz, 20mas res. 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 • EVLA: AU-scale imaging of large dust grain emission • JWST: image dust shadow on scales 10’s mas • Herschel: dust spectroscopy

  18. TW Hya -- Molecular gas SMA: Gas mass, rotation ALMA: dynamics at sub-AU, sub-km/s resolution SMA ALMA simulation Wilner

  19. IV. At the extremes of physics • Extreme gravity: using pulsars to detect nHz gravity waves • TeV sources: explained by VLBI! Credit: Bill Saxton, NRAO

  20. Gravitational Wave Detection using a ‘pulsar timing array’ withNANOGrav (Demorest +) • 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) Predicted timing residuals Predicted timing residuals D. Backer

  21. NanoGrav Credit: D. Manchester, G. Hobbs

  22. LS I +61 303: Solving the TeV mystery Harrison + 2000 Xray • Discovered 1976 @ 100 MeV; variable 5 GHz emission. • High mass binary: 12 Mסּ Be * , 1–3Mסּ 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: • Accretion powered relativistic jet (microQuasar?) • Compact pulsar wind nebula Radio > 400 GeV Albert+ 2006

  23. VLBA Images vs. Orbital Phase(orbit exaggerated) VLBA resolution ~ 2AU Dhawan + Be VLBA movie shows 'cometary' morphology => a Pulsar Wind Nebula shaped by the Be star envi-ronment, not a relativistic jet.

  24. 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.

  25. 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

  26. END

  27. Current large programs: VLA, VLBA, GBT • 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 AUI Operations Review February 29 – March 1, 2008

  28. 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/yr GR = 5.07 deg/yr Kramer et al., 2006, Science, 314, 97

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