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Lunatic fringe: probing the dark ages from the dark side of the Moon C. Carilli (NRAO), Sackler Cosmology Conf, Cambridge, MA, 2008 Judd Jackie
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Supermassive black hole: L bol = 1e14 L o Black hole: ~3 x 10 9 M o Gunn Peterson trough => near edge of reionization Radio astronomy pushing into reionization: gas, dust, star formation in QSO host galaxies at z>6 1” ~ 6kpc CO3-2 VLA S ~ 0.6 mJy Host galaxy: Massive reservoir of gas and dust = fuel for galaxy formation Dust mass ~ 7e8 M o Gas mass ~ 2e10 M o + J1148+5251 z=6.42
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Fine structure lines: [CII] 158um at z=6.4 Dominant ISM gas coolant = star formation tracer z>4 => FS lines observed in (sub)mm bands [CII] size ~ 6kpc ~ molecular gas => distributed star formation SFR ~ 6.5e-6 L [CII] ~ 3000 M o /yr 1” [CII] + CO 3-2 [CII] [NII] IRAM 30m Plateau de Bure
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Break-down of black hole -- bulge mass relation at very high z: BH forms first? High z QSO hosts Low z QSO hosts Other low z galaxies
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Extreme downsizing: building giant elliptical galaxies + SMBH at t univ < 1Gyr Radio detections at z>5.7: only direct probe of host galaxies 10 dust (1/3 of QSO sample) => dust mass > 1e8 M o 4 CO => gas mass > 1e10 M o 2 [CII] => SFR > 1000 M o /yr 10.5 8.1 Li et al. Harvard models: stellar mass ~ 1e12 M o forms in series of major, gas rich mergers starting at z~14, driving SFR > 1e3 M o /yr; SMBH of ~ 2e9 M o forms via Eddington-limited accretion + mergers Evolves into giant elliptical galaxy in massive cluster (3e15 M o ) by z=0 Rapid enrichment of metals, dust, gas within 1 Gyr of Big Bang Currently limited to pathologic objects (HyLIRGs: FIR > 1e13 L o )
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AOS Technical Building ALMA will have uJy line sensitivity in few hours => image gas, dust in ‘normal’ galaxies (LBGs, LAEs) to z ~ 10 Early science: Q4 2010 Atacama Large Millimeter Array: an order of magnitude, or more, improvement in all areas of (sub)mm interferometry, at 5000m in Chile (‘half-way to the Moon’)
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Dark Ages 15 < z < 200 Age of enlightenment 6 < z < 15 Dark ages: possible lunar imperative? Reionization: 100 MHz to 200 MHz, HI 21cm signal being explored by ‘path- finders’
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Long History of Lunar Low Freq Telescope Gorgolewski 1965: Ionospheric opacity Ionosphere p ~ 10 MHz ISM p ~ 0.1 MHz Interstellar scattering => size ~ 1 o ( /1 MHz) -2 Faraday rotation => no polarization z > 140 => not (very) relevant for HI 21cm studies, ‘beyond dark ages’ New window Lunar window ion. cutoff ~ 30m ISM cutoff ~ 3km
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Return to moon is Presidential national security directive (an order, not a request). Summary of STScI Workshop, Mario Livio, Nov. 2006 “The workshop has identified a few important astrophysical observations that can potentially be carried out from the lunar surface. The two most promising in this respect are: (i)Low-frequency radio observations from the lunar far side to probe structures in the high redshift (10 < z< 100) universe and the epoch of reionization (ii)Lunar ranging experiments…” Our concensus: Lunar imperative awaits lessons from ground- arrays
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Heavy lifting: future launch vehicles Ares I Ares V 10m diameter faring Lifting power = 65 tons to Moon
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Size ~ 1’ ( z) -2 < typical scales of interest Scattering can lead to calibration errors => dynamic range limits DR ~ N/(2 1/2 rad ) Required DR ~ 1e6 => < 0.02 o Virgo A field, VLA 74 MHz Lane + 02 Lunar Advantage I: Ionospheric phase distortions
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See talk by J. Lazio Clementine (NRL) star tracker Lunar ionosphere? -- LUNA orbiter detected plasma layer > 10 km above surface -- Apollo surface+subsatellite: detected photoionized layer extending to 100km -- p = 0.2 to 1 MHz * large day/night variation * small e does not necessarily imply small electronic pathlength variations
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Advantage II: Interference Lunar shielding of Earth’s auroral emission at low freq (Radio Astronomy Explorer 1975) Alexander + 1975 12MHz
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The Moon is radio protected ARTICLE 22 (ITU Radio Regulations) Space services Section V – Radio astronomy in the shielded zone of the Moon 22.22 § 8 1) In the shielded zone of the Moon 31 emissions causing harmful interference to radio astronomy observations 32 and to other users of passive services shall be prohibited in the entire frequency spectrum except in the following bands: 31 32 22.23 a) the frequency bands allocated to the space research service using active sensors; 22.24 b) the frequency bands allocated to the space operation service, the Earth exploration-satellite service using active sensors, and the radiolocation service using stations on spaceborne platforms, which are required for the support of space research, as well as for radiocommunications and space research transmissions within the lunar shielded zone. 22.25 2) In frequency bands in which emissions are not prohibited by Nos. 22.22 to 22.24, radio astronomy observations and passive space research in the shielded zone of the Moon may be protected from harmful interference by agreement between administrations concerned.
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Other advantages Easier deployment: robotic or human Easier maintenance (no moving parts) Less demanding hardware tolerances Very large collecting area, undisturbed for long periods (no weather, no animals, not many people) Avi Miguel
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z=50 z=150 NPS Lunar challenges: dark age signal sensitivity Statistical detection 1 SKA, 1 yr, 30MHz (z=50), 0.1MHz T Bsky = 100 ( /200MHz) -2.7 K = 1.7e4 K At l=3000, k=0.3 Mpc -1 Signal ~ 2 mK Noise PS ~ 1 mK Requires few SKAs
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Apollo 15 Array data rates (Tb/s) >> telemetry limits, requiring in situ processing, ie. low power super computing (LOFAR/Blue Gene = 0.15MW) RFI shielding: How far around limb is required? Thermal cycling (mean): 120 K to 380 K Radiation environment Regolith: dielectric/magnetic properties Other challenges Lunar shielding at 60kHz Takahashi + Woan
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Tsiolkovsky crater (100 km diameter) 20°S 129°E Apollo 15 Solution: polar craters of eternal darkness, peaks of eternal light = eternal power But how sharp is the knife’s edge?
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DALI - LAMA: A path to enlightenment NASA funded joint design study Dark Ages Lunar Interferometer (Lazio) Lunar Array for Measuring 21cm Anisotropies (Hewitt) Science (Loeb, Furlanetto) Science requirements (Carilli, Taylor) Antennas (Bradley, MacDowall) Receivers (Backer, Ellingson) Correlator (Ford, Kasper) Data communication (Ford, Neff) Site selection (Hoffman, Burns) Deployment (de Weck, DeMaio) Engineering: power/mech/therm Goal: DS2010 white paper with mission concept, (rough) costing, and technological roadmap
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2010 -- 2020: technology development <2010: mission concept study 2020 -- 2025: Design/Fabrication/Test 2026+: operations Interim programs Orbiter: RFI, ion First dipoles: environ., phase stability Global signal
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+ ARES V Launch fee ~ $700M Total ~ $2G Budget WAG (Hewitt/LARC)
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Say, its only a PAPER moon Sailing over a cardboard sea But it wouldn't be make-believe If you believed in me Rich Don
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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 M o /yr = LBGs, LAEs) at z ~ 6, and derive z directly from mm lines., GBT
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European Aeronautic Defence and Space Corporation/ASTRON (Falcke) Payload = 1000 kg (Ariane V) 100 antennas at 1-10 MHz ~ 1/10 SKA
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FIR excess -- follows Radio-FIR correlation: SFR ~ 3000 M o /yr CO excitation ~ starburst nucleus: T kin ~ 100K, n H2 ~ 1e5 cm^-3 Radio-FIR correlation 50K Elvis QSO SED Continuum SED and CO excitation: ISM physics at z=6.42 NGC253 MW
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Deployment Javelin ROLS: polyimide circuit-imprinted film Dipoles: robotic with rover Dipoles manually
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100 people km^-2 1 km^-2 0.01 km^-2 Chippendale & Beresford 2007 Moon? 100 people km^-2 1 km^-2 0.01 km^-2 0 km^-2 Lunar advantage II: terrestrial interference shielding
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