1 of 29

Simulations:�The Loop from Science to Engineering�and back

S.A. Torchinsky�SKADS Project Scientist

S.A. Torchinsky

SKADS Workshop 10 October 2007

2 of 29

SKADS Science Simulations

?

In the context of technological constraints

S.A. Torchinsky

SKADS Workshop 10 October 2007

3 of 29

2005: Key Science

  • Pune meeting: Key Science agreed
    • Large Scale Structure (HI galaxy survey)
    • Epoch of Reionisation
    • Cosmic Magnetism
    • Tests of General Relativity in extreme fields (Pulsars)
    • Cradle of Life (protoplanetary disks, planets, organic molecules)

S.A. Torchinsky

SKADS Workshop 10 October 2007

4 of 29

SKA Science Book

Chris Carilli & Steve Rawlings,

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

​

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

S.A. Torchinsky

SKADS Workshop 10 October 2007

5 of 29

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

SKADS Workshop 10 October 2007

6 of 29

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, no-hair theorem, cosmic censorship
  • Pulsar timing array
    • Gravitational wave background

S.A. Torchinsky

SKADS Workshop 10 October 2007

7 of 29

Probing the Dark Ages

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

​

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

Furlanetto

S.A. Torchinsky

SKADS Workshop 10 October 2007

8 of 29

Large Scale Structure

Local hydrogen

Hydrogen in a distant galaxy

Billions of galaxies!

S.A. Torchinsky

SKADS Workshop 10 October 2007

9 of 29

BAO and Dark Energy

  • Improve signal confidence by measuring wiggles in separate redshift bins

Blake et al 2004: example assuming w=-0.8, peaks don’t line up with CMB peaks (vertical lines)

S.A. Torchinsky

SKADS Workshop 10 October 2007

10 of 29

Cosmic Shear

  • Integrated gravitational lensing along line-of-sight
    • “weak lensing”
  • Requires large statistics
    • SKA continuum survey of 10 Billion galaxies
    • Clean sample
      • Reject star burst galaxies which may be the result of mergers�(morphological alignment not the result of cosmic shear)
      • Still have a large sample with SKA
    • Improve result with analysis in redshift bins
      • Redshifts from SKA HI survey

S.A. Torchinsky

SKADS Workshop 10 October 2007

11 of 29

Cosmic Magnetism

  • Origin of magnetic fields
    • Dynamo?
    • Primordial?

​

S.A. Torchinsky

SKADS Workshop 10 October 2007

12 of 29

Cradle of Life

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

​

S.A. Torchinsky

SKADS Workshop 10 October 2007

13 of 29

Key Projects plus two

?

transients

the unknown

S.A. Torchinsky

SKADS Workshop 10 October 2007

14 of 29

Transient signal

S.A. Torchinsky

SKADS Workshop 10 October 2007

15 of 29

Transients

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

​

requires:

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

S.A. Torchinsky

SKADS Workshop 10 October 2007

16 of 29

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

SKADS Workshop 10 October 2007

17 of 29

SKADS Science Interactions

The Universe

Our understanding of the Universe

Sky Simulation (DS2T1)

Convolution with the telescope (DS2T2)

Network simulator (DS3T3)

Technology development �(DS4)

Technology demonstrators�(DS5 & DS6)

observations

brain power

Catalogs, images, EM fields

voltages

measurements�and�simulated performance

Request spec change�BENCHMARK

Backend data

Data imaging�(DS2T2)

Simulated telescope image

Data analysis (DS2)

science goals achievable?

S.A. Torchinsky

SKADS Workshop 10 October 2007

18 of 29

SKADS Science Interactions

The Universe

Our understanding of the Universe

Sky Simulation (DS2T1)

Convolution with the telescope (DS2T2)

Network simulator (DS3T3)

Technology development �(DS4)

Technology demonstrators�(DS5 & DS6)

observations

brain power

voltages

measurements�and�simulated performance

Backend data

Data imaging�(DS2T2)

Simulated telescope image

Request spec change�BENCHMARK

Catalogs, images, EM fields

Data analysis (DS2)

science goals achievable?

Consider trade-offs

NO: not technologically feasible

NO: too expensive

YES: We can do better than that !

SKADS�Design & Costing

S.A. Torchinsky

SKADS Workshop 10 October 2007

19 of 29

SKADS Science Simulations

  • Pure sky simulations (DS2T1) feed back into telescope simulations, configuration studies, (DS2T2) and costing (DS3)
  • Key projects drive technical requirements, e.g.
    • Field of view (mapping speed)
    • Total Frequency range
    • Instantaneous bandwidth
    • Spectral resolution
    • Angular resolution
    • Sensitivity (Aeff/Tsys)

​

S.A. Torchinsky

SKADS Workshop 10 October 2007

20 of 29

Simulations in Publications

S.A. Torchinsky

SKADS Workshop 10 October 2007

21 of 29

Simulations for the SKA

Proceedings of the meeting held at�Pushchino Radio Astronomy Observatory, Russia�30 July – 1 August 2007

edited by S.A. Torchinsky

S.A. Torchinsky

SKADS Workshop 10 October 2007

22 of 29

Pushchino Meeting

  • Simulations for the SKA
  • 30 July to 1 August in Pushchino, Russia
  • ~30 participants
  • Proceedings (nearly) produced
    • Currently 62 pages, waiting for the last few contributions

​

S.A. Torchinsky

SKADS Workshop 10 October 2007

23 of 29

Pushchino Proceedings (1/3)

S.A. Torchinsky

SKADS Workshop 10 October 2007

24 of 29

Pushchino Proceedings (2/3)

S.A. Torchinsky

SKADS Workshop 10 October 2007

25 of 29

Pushchino Proceedings (3/3)

S.A. Torchinsky

SKADS Workshop 10 October 2007

26 of 29

Science Involvement in EMBRACE

  • Test and evaluation of EMBRACE

S.A. Torchinsky

SKADS Workshop 10 October 2007

27 of 29

DS5T3 Evaluation of EMBRACE

  • Demonstrate that EMBRACE can be used for astronomical observations
    • Pulsar timing
    • Multibeam pulsar timing
    • HI mapping
    • Continuum mapping
    • Source tracking
    • Observations in the presence of strong sources (moon, sun)
    • Correlation with long baseline (Westerbork – Nançay)
    • Engineering/characterisation testing
      • Beam profile, Tsys, Aeff, etc,
  • Opportunity to have first-hand experience using AA for astronomy
  • Head-start for exploiting SKA

S.A. Torchinsky

SKADS Workshop 10 October 2007

28 of 29

SKADS Science Simulations

?

In the context of technological constraints

S.A. Torchinsky

SKADS Workshop 10 October 2007

29 of 29

SKADS Webpage

www.skads-eu.org

S.A. Torchinsky

SKADS Workshop 10 October 2007