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Chicago III, Sept. 15, 2007 Washington DC Chris Carilli (NRAO) Thermal science at centimeter wavelengths, and more! High Frequency (> 10GHz) Laundry list of high frequency science with SKA (what we lose without >10GHz) • First light: molecular line studies of the first galaxies** • Cradle of life: Terrestrial planet formation and pre-biotic molecules • Cosmology: Extragalactic water masers and measurement of Ho • Testing GR: Pulsars in the Galactic Center • SZ effect at 30GHz • Molecular abs line systems and the variation of the fundamental constants • Stellar masers (SiO, H2O) -- late stages of stellar evolution • NH3 • Solar system thermal objects: atmospheres, surfaces, asteroids, KBO, comets • Spacecraft tracking and telemetry at 32GHz: movies from Mars • Stellar photospheres, winds, outflows • FF/RRL -- HII regions, SuperStarClusters …. **Key Science Projects ALMA/EVLA CO redshift coverage Epoch of Reionization: Benchmark indicating formation first luminous Objects = Last frontier First galaxies: standard molecular transitions redshift to cm regime •Total gas mass •Gas dynamics •Gas excitation •High density gas tracers ^2 ALMA z~10 Starbursts CO Excitation ladder Normal galaxies Weiss, Walter, Downes, Henkel, in prep. First galaxies -- Radio astronomy into cosmic reionization z ~ 6 QSO host galaxies: molecular gas and dust 50K FWHM=350 km/s Radio-FIR correlation Mdust ~ 1e8 Mo Dust heating: star formation or AGN? Follows Radio-FIR correlation: SFR ~ 3000 Mo/yr z=6.42 VLA PdBI • Giant reservoirs of molecular gas ~2e10 Mo = fuel for star formation. • Currently: 2 solid detections, 2 likely at z~6 VLA of CO3-2 VLAJ1148+52: imaging of gasimaging at subkpc resolution 0.4”res rms=50uJy at 47GHz 1” 5.5kpc 0.15” res Not just circumnuclear disk. Separation = 0.3” = 1.7 kpc Can AGN heat dust kpc-scales (geometry/rad transfer)? TB = 20K => Typical of starburst nuclei Gas dynamics: Potential for testing MBH - Mbulge relation at high z -- only direct probe of host galaxies 1148+5251 z=6.42 Mdyn~ 2e10/(sin)^2 Mo Mgas~ 2e10 Mo Mbulge ~1e12 Mo (predicted) z<0.5 MBH = 0.002 Mbulge [CII] 158um ISM gas cooling line at z=6.4 C+ = workhorse line for z>6 galaxies with ALMA 30m 256GHz Maiolino etal Structure identical to CO 3-2” (~ 5 kpc) => distributed gas heating = star formation? SFR ~ 6.5e-6 L[CII] ~ 3000 Mo/yr CII PdBI Walter et al. 1” CII + CO 3-2 Higher Density (>1e4 cm^-3) Tracers: HCN, CN, & HCO+, HCN 1-0 HCO+ 1-0 Riechers 200uJy •Cloverleaf (z=2.56) = SgrB2 of distant galaxies •Lines 5-10x fainter than CO •ncr > 1e7cm^-3 for higher orders => higher order not (generally) excited? •Dense gas tracers best studied with cm telescopes CO vs. HCN: total vs. dense gas 1e13 FIR Index=1.5 Index = 1 1e9 L’(CO) • CO traces all molecular gas (>100 cm^-3) • SFR / total gas mass = star formation efficiency, increases with FIR luminosity. L’(HCN) HCN traces dense gas (> 1e4 cm^-3) SFR / dense gas mass ~ universal in all galaxies: ‘Counting star forming clouds’ Building a giant elliptical galaxy + SMBH at tuniv < 1Gyr Multi-scale simulation isolating most massive halo in 3 Gpc^3 (co-mov) 10 10.5 Li, Hernquist, Roberston.. 8.1 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 6.5 Evolves into giant elliptical galaxy in massive cluster (3e15 Mo) by z=0 • Enrichment of heavy elements, dust starts early (z > 8): good news for radio astronomy • Extreme and rare objects: ~ 100 SDSS z~6 QSOs on entire sky • Integration times of hours to days to detect HyLIGRs The need for collecting area: pushing to normal galaxies at high redshift -- spectral lines cm telescopes: low order molecular transitions (sub)mm: high order molecular lines + fine structure lines The need for collecting area: continuum A Panchromatic view of galaxy formation Arp 220 vs z cm: Star formation, AGN (sub)mm Dust, molecular gas Near-IR: Stars, ionized gas, AGN The Cradle of Life (Wilner) • image terrestrial planet formation zone of disks – grain growth to pebbles – embedded protoplanets and sub-AU tidal gaps – Evolution ~ 1 year Bryden 1999 • assess biomolecules – disk abundances – locations Remijan et al. 2006 Terrestrial Planet Formation • T Tauri, Herbig Ae stars: several l00’s of proto-Sun analogs, d ~ 140 pc, age 1-10 Myr – How do terrestrial planets form? – How much orbital evolution (migration)? – Is our Solar System architecture typical? 1.3 mm • SKA: unique probe of disk habitable zone – mas resolution: 1AU = 7mas at 140pc – cm waves: avoid dust opacity – very high sensitivity: thermal emission • Complementarity – ALMA: Chemistry, dynamics, dust on larger scales – Optical: scattered light star dust SKA Sensitivity: thermal science at mas resolution • SKA 8hrs, 22GHz, 2mas (1500km) => S(rms) = 0.02uJy, TB(rms) = 11K • flux density emitted by a disk element dA TB ~ 50 to 300 K on AU scales • less than an Earth mass in sub-AU beam at 140 pc distance of nearby dark clouds Embedded Protoplanets • protoplanet interacts tidally with disk – transfers angular mom. – opens gap – viscosity opposes P. Armitage QuickTime™ and a YUV420 codec decompressor are needed to see this picture. • orbital timescales in habitable zone are short (t ~ 1 yr) • synoptic studies track proper motions of mass concentrations Bate et al. 1AU Gap ~ 100 K Grain Growth and Settling • detailed frequency dependence of dust emissivity is diagnostic of particle properties, esp. size • SKA sensitive to cm sizes, predicted to settle to disk mid-plane and seed planetesimals -- sticky question? QuickTime™ and a YUV420 codec decompressor are needed to see this picture. TW Hya 3.5 cm dust Wilner et al NASA/JPL R. Hurt . Cosmology -- Water maser disks (Greenhill) • Hubble constant through direct measurement of distances to galaxies in the Hubble flow. • Distance to NGC 4258 = 7.4 Mpc +/- 4% -- maser acceleration and proper motion -- problem: NGC 4258 is too close => Cepheid calibrator • Earth baselines => resolution > 0.4 mas => max. distance ~ 120 Mpc • Currently ~ 30 NGC4258-like masers known • SKA: ~ 100x more sources, with adequate sensitivity to image => easily 1% measure of Ho Why do we need to know Ho to 1% ? w ~ 1 +/- 0.13 Future 1% measures of cosmological parameters via CMB studies require 1% measure of Ho for fully constrained cosmology: covariance! (w) Current Ho constraint 0.09 Ho accur. 10% 4% GR tests: Galactic Center Pulsars (Cordes) •Sgr A* = 3106 black hole with a surrounding star cluster with ~ 108 stars. Many of these are neutron stars. •Detecting pulsars near Sgr A* is difficult because of the intense scattering screen in front of Sgr A*: d ~ 2000 ν-4 sec (but S ^-3) •Solution: high sensitivity at high frequency: > 10GHz => width < 0.2sec Key science: • Highest probability of finding binary BHpulsar: strong field GR tests and BH spin. • Possibly 1000 pulsars orbiting Sgr A* with orbital periods < 100 yr • Detailed studies of GC ISM -- DM… Summary and Ruminations KSP 10% Big step? Up to 45GHz? >1000km? First light: mol. lines Y Y N Terrestrial planet formation: PP disks Y Y Y Gal. Center Pulsars Y N N Cosmology: water masers Y and Ho N Y • SKA-High is not being pursued by international partners. • SKA-High is most consistent with current work in USA (EVLA, ATA, DSN). Case for frequencies up to 45 GHz: Thermal objects Rayleigh-Jeans curve implies thermal objects are a factor four stronger (in Jy) at 45GHz relative to 22GHz => a 10% demonstrator becomes 40% of the SKA-22, Or EVLA at 45GHz ~ 8% SKA-22GHz demonstrator 0.1 x Arp220 25-50GHz 10% demonstrator What we lose without 3 -- 10 GHz • mas resolution -- Astrometry! Jets, AGN, XRBs • GRBs, RSNe • Methanol masers: massive star formation • Large RM sources • ms Pulsars with moderate DM …. END