S.A. TorchinskySKADS Workshop 10 October 2007

Simulations:Simulations:

The Loop from Science to EngineeringThe Loop from Science to Engineering

and backand back

S.A. TorchinskySKADS Project Scientist

S.A. TorchinskySKADS Workshop 10 October 2007

SKADS Science SimulationsSKADS Science Simulations

?In the context of technological constraints

S.A. TorchinskySKADS Workshop 10 October 2007

2005: Key Science2005: 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. TorchinskySKADS Workshop 10 October 2007

Chris Carilli & SteveSteve RawlingsRawlings,

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

SKA Science BookSKA Science Book

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

S.A. TorchinskySKADS Workshop 10 October 2007

Strong Field Tests of GravityStrong 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. TorchinskySKADS Workshop 10 October 2007

Strong Field Tests of GravityStrong 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. TorchinskySKADS Workshop 10 October 2007

Probing the Dark AgesProbing 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. TorchinskySKADS Workshop 10 October 2007

Local hydrogen

Hydrogen in a distant galaxy

Large Scale StructureLarge Scale Structure

Billions of galaxies!

S.A. TorchinskySKADS Workshop 10 October 2007

BAO and Dark EnergyBAO 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. TorchinskySKADS Workshop 10 October 2007

Cosmic ShearCosmic 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. TorchinskySKADS Workshop 10 October 2007

Cosmic MagnetismCosmic Magnetism

• Origin of magnetic fields– Dynamo?

– Primordial?

S.A. TorchinskySKADS Workshop 10 October 2007

Cradle of LifeCradle of Life

• Protoplanetary disks resolved to Earth-like orbits

• Organic molecules

• Extrasolar planets

• Extra terrestrial intelligence

S.A. TorchinskySKADS Workshop 10 October 2007

Key Projects plus twoKey Projects plus two

?transients

the unknown

S.A. TorchinskySKADS Workshop 10 October 2007

Transient signalTransient signal

S.A. TorchinskySKADS Workshop 10 October 2007

TransientsTransients

• Pulsar is a special case of transient phenomena (periodic)

• Giant pulses

• Supernova

• Bursters

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

S.A. TorchinskySKADS Workshop 10 October 2007

The UnknownThe 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. TorchinskySKADS Workshop 10 October 2007

SKADS Science InteractionsSKADS Science InteractionsThe 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

mea

sure

men

tsan

dsi

mu

late

d pe

rfor

man

ceRequest spec changeBENCHMARK

Backend data

Data imaging(DS2T2)

Simulated telescope image

Data analysis (DS2)

science goals achievable?

S.A. TorchinskySKADS Workshop 10 October 2007

SKADS Science InteractionsSKADS Science InteractionsThe 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

mea

sure

men

tsan

dsi

mu

late

d pe

rfor

man

ce

Backend data

Data imaging(DS2T2)

Simulated telescope image

Request spec changeBENCHMARK

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 !

SKADSDesign & Costing

S.A. TorchinskySKADS Workshop 10 October 2007

SKADS Science SimulationsSKADS 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. TorchinskySKADS Workshop 10 October 2007

Simulations in PublicationsSimulations in Publications

S.A. TorchinskySKADS Workshop 10 October 2007

Simulations for the SKASimulations for the SKA

Proceedings of the meeting held atPushchino Radio Astronomy Observatory, Russia30 July – 1 August 2007

edited by S.A. Torchinsky

S.A. TorchinskySKADS Workshop 10 October 2007

Pushchino MeetingPushchino 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. TorchinskySKADS Workshop 10 October 2007

Pushchino Proceedings (1/3)Pushchino Proceedings (1/3)

S.A. TorchinskySKADS Workshop 10 October 2007

Pushchino Proceedings (2/3)Pushchino Proceedings (2/3)

S.A. TorchinskySKADS Workshop 10 October 2007

Pushchino Proceedings (3/3)Pushchino Proceedings (3/3)

S.A. TorchinskySKADS Workshop 10 October 2007

Science Involvement in Science Involvement in EMBRACEEMBRACE

• Test and evaluation of EMBRACE

S.A. TorchinskySKADS Workshop 10 October 2007

DS5T3 Evaluation of EMBRACEDS5T3 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. TorchinskySKADS Workshop 10 October 2007

SKADS Science SimulationsSKADS Science Simulations

?In the context of technological constraints

S.A. TorchinskySKADS Workshop 10 October 2007

SKADS WebpageSKADS Webpage

www.skads-eu.org