Square Kilometre Array Steve Torchinsky steve.torchinsky@obspm.fr
A square kilometre of collecting area for each of three frequency bands SKA Low frequency 50MHz to 450MHz to be built in Western Australia SKA Mid and High frequency 450MHz to 14GHz to be built in the Karoo desert of South Africa Fundamental Physics: The formation of large scale structure and the first luminous objects The distribution of mass in the Universe and the nature of the Dark Energy The origin of magnetic fields in the Universe The limits of General Relativity Gravitational Waves from black hole mergers and possibly from the Big Bang The formation of planetary systems and the detection of bio markers (pre-biotic molecules, artificially generated transmissions from ETI) Transient phenomena at very fast time scales (Bursts from Active Galactic Nuclei and others) Advanced Technology: Over 107 antenna elements. Digitization of over a million Radio Frequency signals. Digital signal transport 100x times today's global internet traffic Super computers with 100 petaflop capability Exabyte data archive 2
SKA Science Book 135 chapters, 1200 co-authors Available at Proceedings of Science https://www.skatelescope.org/news/ska-science-book/ http://pos.sissa.it/cgi-bin/reader/conf.cgi?confid=215 3
Tests of Gravity with Pulsars Relativistic effects measured by timing pulsar clock ticks permit (re) determination of binary masses. Pulsar timing array will detect Gravitational Waves of nhz (galactic length scale) 4
Dark Energy Baryonic Acoustic Oscillations BAO signature traces the length scale of the Universe at different epochs. This gives the evolution of Dark Energy and the Equation of State of the Universe. There are fluctuations at all scales but there is a preferred scale of around 1 deg. 5
Science Requirements Translating Science Requirements to Technical Specifications Redshift, velocity dispersion, survey extent and precision, sensitivity,... Frequencies, spectral resolution, Field of View, angular resolution, system temperature,... Torchinsky et al. (2016) arxiv:1610.00683 6
Partners 10 members Australia: Department of Industry and Science Canada: National Research Council China: Ministry of Science and Technology of the People's Republic of China India: National Centre for Radio Astrophysics Italy: National Institute for Astrophysics New Zealand: Ministry of Economic Development South Africa: National Research Foundation Sweden: Onsala Space Observatory The Netherlands: Netherlands Organisation for Scientific Research United Kingdom: Science and Technology Facilities Council 7
Design and Development 100 organisations across about 20 countries: All member countries plus: Brazil France Japan Malta South Korea Poland Portugal Russia Spain USA 8
Workpackages Assembly, Integration and Verification (AIV) Central Signal Processor (CSP) Dish (DSH) Infrastructure Australia and Africa (INFRA AU/INFRA SA) Low-Frequency Aperture Array (LFAA) OCA Mid-Frequency Aperture Array (MFAA) Nancay, Bordeaux Signal and Data Transport (SaDT) Science Data Processor (SDP) Telescope Manager (TM) Wideband Single Pixel Feeds (WBSPF) Bordeaux Bordeaux 9
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Mid Frequency Aperture Array EMBRACE
Mid Frequency Aperture Array Densely packed antennas (Nyquist spacing: λ/2 at 1200MHz) Analogue beamforming of antenna groups 0.5m 2 (32 antennas) Possibility for correlation minimum baseline ~1m Frequency range: 450MHz 1450MHz Proposed for the SKA Phase 2 (2028) Consortium led by ASTRON (NL) Obs de Paris U. Manchester MID-FREQUENCY APERTURE ARRAY Cambridge U. Oxford U. SKA South Africa ENGAGE-SKA Portugal Steve Torchinsky, 7 November 2016 Square Kilometre Array Cosmology Group, APC, Paris
MFAA Prototype: EMBRACE Operational at Nancay since 2011 A&A, 589, A77 (2016) MID-FREQUENCY APERTURE ARRAY EMBRACE@Nançay Steve Torchinsky, 7 November 2016 Square Kilometre Array Cosmology Group, APC, Paris
Beamformer Chip 17
Galaxy Detection EMBRACE@Nançay 18
EMBRACE Characterization and Results MID-FREQUENCY APERTURE ARRAY Steve Torchinsky, 7 November 2016 Square Kilometre Array Cosmology Group, APC, Paris
EMBRACE limitations for science 70m2 Single polarization RF environment Especially digital television emitter nearby MID-FREQUENCY APERTURE ARRAY EMBRACE filtered below 900MHz Steve Torchinsky, 7 November 2016 Square Kilometre Array Cosmology Group, APC, Paris
MANTIS: Next generation MFAA prototype To be built on the SKA South Africa site Radio quiet site Dual polarization 450MHz - 1450MHz ~1000m Proposed science: 2 MID-FREQUENCY APERTURE ARRAY Intensity Mapping for BAO Fast Radio Burst and other transients Goal for operation at the same time as SKA Phase 1 (~2020) Seeking funding Steve Torchinsky, 7 November 2016 Square Kilometre Array Cosmology Group, APC, Paris
MANTIS proposal MID-FREQUENCY APERTURE ARRAY Steve Torchinsky, 7 November 2016 Square Kilometre Array Cosmology Group, APC, Paris
Future Developments Future development towards a large prototype To be built on the SKA site in South Africa (seeking funding) Various frontends proposed Vivaldi array (EMBRACE) Octogonal Ring Array collaboration: Manchester/Nancay LNA, beamformer chips, provided by Nancay INFIERI ESR working on design and testing at Nancay (Tailei Wang) 23