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Square Kilometre Array

S.A. Torchinsky�SKADS Project Scientist

www.skads-eu.org

S.A. Torchinsky

Square Kilometre Array

Origins, CIEP Sèvres, 16 October 2007

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Square Kilometre Array

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S.A. Torchinsky

Square Kilometre Array

Origins, CIEP Sèvres, 16 October 2007

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SKA Key Science

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Tests of gravity

Epoch of Reionisation

Cosmic Magnetism

Cradle of Life

Large Scale Structure

Transient Universe

The Unknown

S.A. Torchinsky

Square Kilometre Array

Origins, CIEP Sèvres, 16 October 2007

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SKA Science Book

Chris Carilli & Steve Rawlings,

New Astronomy Reviews, Vol.48, Elsevier, Dec. 2004

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http://www.skads-eu.org/p/SKA_SciBook.php

S.A. Torchinsky

Square Kilometre Array

Origins, CIEP Sèvres, 16 October 2007

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Strong Field Tests of Gravity

Binary orbit permits determination of masses

Relativistic effects permit (re) determination of masses.

ALL MUST AGREE

http://www.jb.man.ac.uk/~pulsar/

S.A. Torchinsky

Square Kilometre Array

Origins, CIEP Sèvres, 16 October 2007

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Strong Field Tests of Gravity

  • Large surveys will find exotic binarys
    • ~20 000 pulsars in the galaxy
    • Nearly edge-on Pulsar – Black-hole binary (at least one)
      • Probe eg. Frame dragging, cosmic censorship, no hair theorem
  • Pulsar timing array
    • Gravitational wave background

S.A. Torchinsky

Square Kilometre Array

Origins, CIEP Sèvres, 16 October 2007

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Probing the Dark Ages

  • When did the first luminous objects form?
  • How did they form and over what period of time?

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  • SKA will detect the Epoch of Reionisation and map the evolution history of the first luminous objects

Di Matteo et al

S.A. Torchinsky

Square Kilometre Array

Origins, CIEP Sèvres, 16 October 2007

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Cosmic Magnetism

  • Origin of magnetic fields
    • Dynamo?
    • Primordial?

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NGC 891 (Krause)

M 51 VLA+Eff 6cm

(Fletcher & Beck)

S.A. Torchinsky

Square Kilometre Array

Origins, CIEP Sèvres, 16 October 2007

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Large Scale Structure

Billions of galaxies!

S.A. Torchinsky

Square Kilometre Array

Origins, CIEP Sèvres, 16 October 2007

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Baryonic Acoustic Oscillations

  • Improve signal confidence by measuring wiggles in separate redshift bins
  • A catalog of a billion galaxies
  • Position and redshift measured simultaneously
  • There are fluctuations at all scales but there is a preferred scale of around 1 deg.

S.A. Torchinsky

Square Kilometre Array

Origins, CIEP Sèvres, 16 October 2007

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Complementarity with Planck

1%

S.A. Torchinsky

Square Kilometre Array

Origins, CIEP Sèvres, 16 October 2007

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Cradle of Life

  • Protoplanetary disks resolved to Earth-like orbits
  • Organic molecules
  • Extrasolar planets
  • Extra terrestrial intelligence

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S.A. Torchinsky

Square Kilometre Array

Origins, CIEP Sèvres, 16 October 2007

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Transient signal

S.A. Torchinsky

Square Kilometre Array

Origins, CIEP Sèvres, 16 October 2007

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Transients

  • Pulsar is a special case of transient phenomena (periodic)
  • Giant pulses
  • Supernova
  • Bursters
  • ETI

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requires:

  • fast time constant
  • memory buffer for post analysis
  • wide instantaneous, fully-sampled FoV

S.A. Torchinsky

Square Kilometre Array

Origins, CIEP Sèvres, 16 October 2007

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The Unknown

  • New discoveries always result from observations in new parameter space
    • sensitivity
    • spatial resolution
    • spectral resolution
    • polarisation
    • time domain
    • observing speed (multibeaming)
  • eg. CMB, pulsars, extra solar planets,…

SKA improves all of these

SKA is designed for the Key Projects but with an overriding design philosophy of flexibility to maximise the likelihood of new discoveries

S.A. Torchinsky

Square Kilometre Array

Origins, CIEP Sèvres, 16 October 2007

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Worldwide SKA efforts

  • Europe
    • LOFAR
    • Square Kilometre Array Design Studies
      • 4 year study, 38MEuro (11MEuro from EU Framework Programme 6)
      • EMBRACE demonstrator at Westerbork and Nançay
  • Australia & Canada
    • AU$56M announced in 2007 Australian budget
    • ASKAP demonstrator
  • South Africa
    • Karoo Array Telescope and MeerKAT
    • Over US$200M confirmed by SA gov’t for construction, infrastructure, including high capacity network to Karoo region.
  • USA
    • Allen Telescope Array
    • Technology Demonstrator Programme (proposed)

www.skads-eu.org

S.A. Torchinsky

Square Kilometre Array

Origins, CIEP Sèvres, 16 October 2007

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SKA Reference Design (1)

S.A. Torchinsky

Square Kilometre Array

Origins, CIEP Sèvres, 16 October 2007

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SKA Reference Design (2)

  • Inner core (~1km) of densely packed phased-array tiles
  • Surrounded by paraboloid dishes (~10m diameter)
  • Dishes may have multibeam feeds (phased arrays or horn clusters)
  • ~200 stations of ~100 dishes each out to a baseline of 3000km

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S.A. Torchinsky

Square Kilometre Array

Origins, CIEP Sèvres, 16 October 2007

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Three Technologies

  • ~1km inner cores
    • sparse aperture arrays (eg. LOFAR)
    • dense aperture arrays (eg. EMBRACE)
    • parabolic dishes
  • Outer core ~5km of stations
  • Arms > 5km of stations
  • maximum baseline of ~3000km

1km

5km

S.A. Torchinsky

Square Kilometre Array

Origins, CIEP Sèvres, 16 October 2007

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SKA Reference Design

S.A. Torchinsky

Square Kilometre Array

Origins, CIEP Sèvres, 16 October 2007

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candidate site: South Africa

  • Karoo radio quiet zone

S.A. Torchinsky

Square Kilometre Array

Origins, CIEP Sèvres, 16 October 2007

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Candidate site: Australia

  • Mileura Radio Quiet Zone

S.A. Torchinsky

Square Kilometre Array

Origins, CIEP Sèvres, 16 October 2007

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Detailed Design for SKA

  • Square Kilometre Array Design Studies
    • 26 institutes in 13 countries
    • 38MEuro (including matching funds and EU funds)
    • Detailed design and costing, including signal transport, processing requirements, construction costs,…
    • www.skads.eu.org/p/memos.php

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www.skads-eu.org

S.A. Torchinsky

Square Kilometre Array

Origins, CIEP Sèvres, 16 October 2007

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SKA Timeline

http://www.skatelescope.org

S.A. Torchinsky

Square Kilometre Array

Origins, CIEP Sèvres, 16 October 2007

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Multibeaming with an Aperture Plane Phased Array

www.skads-eu.org

S.A. Torchinsky

Square Kilometre Array

Origins, CIEP Sèvres, 16 October 2007