C.Carilli, AUI Board October 2006
• ISAC-run three year process: Quantified ‘experiments’ for future large area cm telescopes
• 50 chapters, 90 authors, 25% theorists
Cradle of Life: Terrestrial planet formation + astrobiology + SETI
Cosmic reionization and first light
HI + continuum survey: galaxy evolution and dark energy
Strong field tests of GR using pulsars
Cosmic magnetism: origin and evolution
Key Science Projects: (i) Address key questions, (ii) Unique role of radio, or complementary but critical, (iii) Excites broad community
KSP I: Cosmic magnetism -- Origin, Structure, Evolution
Experiment: All Sky Polarization/Rotation measure survey (σ
0.1 μJy at 1.4GHz) -- 2e7 RMs, spaced by ~ 90" (vs. 1500 currently)
Currently: 300 local pulsar RMs
SKA: 2e4 pulsars
2. Nearby galaxies Synchrotron+RMs: test dynamo models
3. Distant radio galaxies: Intercluster magnetic fields
4. Ly-a absorbers: galaxian magnetic field evolution over cosmic time
5. Cosmic web: the magnetized intergalactic medium
KSP II: Galaxy evolution and dark energy
Experiment: All sky HI line + continuum survey -- 1e9 Galaxies in HI out to z=1.5
Goal 1: Galaxy evolution – conversion gas to stars
1e4/deg^2 in HI to z=0.5 to 1.5
Goal 2: SKA as Dark Energy Machine
DE EoS: w = P/ = -1? Func(z)?
Baryon Oscillations + Weak lensing:
Evolution of LSS -- ‘standard ruler’
w(z) = w0 + w1 z
SKA: variance limited
SKA: measure w(z) to few %
KSP III: Study of Cosmic reionization and first light
The last unexplored phase of cosmic evolution (0.1 to 1Gyr after BB)
z=12 (109MHz) 9 7.6
Experiment: Imaging 3D ‘tomography’ of IGM in HI 21cm line
“Richest of all cosmological data sets”
1e9 M_sun in dust, 1e10 M_sun in mol. gas =>
Hyper luminous IR galaxy (FIR =1e13 L_sun): SFR = 1e3 M_sun/yr ?
Coeval formation of SMBH/galaxy?
Dust formation by massive stars?
Break-down of M- relation at high z?
J1148 VLA: CO 3-2 at 45GHz
1”
SDSS J1148+5251: Observing first light at radio wavelengths
z=6.42; t_univ=0.87 Gyr
Fan +
Early enrichment of heavy elements (z_sf > 8)
Integration times: hours to days on HLIRGs
50K
Complementarity
AGN, star formation
Low order mol. lines
Mol. Gas, dust
Stars, ionized gasSKA
KSP IV: Gravity Beyond Einstein
Experiment: 2e4 Galactic pulsars
Strong field GR tests using pulsar-black hole binaries
Pulsar Timing Array: most sensitive gravity wave detector
for SMBH binaries
KSP V: Cradle of life
• Terrestrial planet formation: disks and gaps on sub-AU scales (complementary with ALMA).
• Prebiotic large molecules (abiotic amino acids)
• Search for Extraterrestrial Intelligence: leakage radiation (interstellar TV)
• All require sensitivity: A/T >= 1e4 m^2/K
• Most require frequencies >= 10 GHz
• Many require > 1deg^2 FoV at 1.4 GHz
• Some require > 1000 km baselines
• A few require multibeaming
END
Pathfinders
Freq (GHz) Year Focus
• EVLA I 0.3 – 50 2012 Broad, thermal
• eMERLIN 1 – 30 2010 High resolution
• ATA 1 – 10 2008? Wide fields
• DSN 8, 32 2010? Telemetry
• LWA 0.03–0.08 2009 Low freq window
• LOFAR 0.08 – 0.3 2009 EoR++
• MWAd 0.1 – 0.3 2009 EoR+
• PAPER 0.1 – 0.2 2008 EoR
• SKADS (europe) 0.1 – 25 2015++ HI survey (aperture array)
• xNTD (Oz) 0.7 – 1.4 2010 HI survey (FPA)
• South Africa 0.7 – 1.4 2010 HI Survey (FPA)
• SKA-TDP (USA) 0.3 – 25 2010 Nd
Goal 4: Hubble constant through direct measurement: Water Maser Disks (Greenhill)• Future 1% measures of CMB and related require 1% measure of Ho for fully constrained cosmological parameters: covariance
• Water masers disks into the Hubble flow can provide direct measure of Ho to 1%
h
Rayleigh-Jeans curve implies thermal objects are a factor four stronger (in Jy) at 45GHz relative to 22 GHz
=> a 10% demonstrator becomes 40% of the SKA
10% demonstrator
Case for frequencies up to 45 GHz: Thermal objects