The international SKA project

The international SKA project - Towards a giant global radio telescope - Wim van Driel Paris Observatory - GEPI 3 rd MCCT SKADS School, Paris, 24/08/2009

SKA - Square Kilometre Array Necessary for a breakthrough in radio astronomy: 100 times more sensitivity Single dish antenna Interferometer Sensitivity of a radio telescope depends on: Collecting surface & system noise Need for a collecting surface of a square kilometre The SKA project

The need for sensitivity at radio frequencies (1) optical Example 1: imaging distant galaxies in radio lines Massive distant galaxy (z~3) Nearby galaxy (out to V~10,000 km/s, z~0.03) CO line (λ 0 2.6 mm; millimetric) HI line (λ 0 21 cm; centimetric) dense molecular gas atomic gas

The need for sensitivity at radio frequencies (2) Example 2: radio continuum sources in the Hubble Deep Field actual telescopes: 8 sources with the SKA: 2700 sources: 150 AGN + starburst

SKA - Square Kilometre Array Towards a collecting surface of a square kilometre (in 2022): Sensitivity of radio telescopes (Moore s law) : has doubled every 3 years; already a factor 100,000 in 60 years Moore s law

SKA basic parameters collecting surface of a square kilometre radio line observations: 100 x more sensitive continuum observations: 1000 x more sensitive (large bandwidths) frequencies: 0.1 25 GHz (λ 1 cm to 3 m) field of view: 50 square degrees @ λ 21 cm independent beams: 8 angular resolution : 0.01 arcsec @ λ 21 cm interferometer; core + stations of 100m, baselines up to 3000 km

Complementarity of future very large instruments Detection of spectral lines of a normal spiral galaxy at z = 2 λ dm mm IR opt

SKA made for very large surveys Example: HI line profiles of a billion galaxies very large field-of-view (at least 50 square degrees) multi-beam instrument 1 square degree Hubble Space Telescope Future millimetric radio telescope Moon

SKA surveys the Need for Speed Example: obtain HI line profiles/imaging of N galaxies, over X square degrees of sky down to low noise level of Y µjy (to get high SNR spectra) Comparison of VLA and SKA survey speed (assume T sys equal): VLA field-of-view 0.25 sq.deg; SKA 50 sq.deg gain factor of 200 in time SKA 50 times more sensitive gain factor of 50 2 = 2500 in time Total gain in survey time = 200 2500 = 500,000 times faster What would take 500 years at the VLA, takes only 10 hours with the SKA Now: 20,000 galaxy HI survey with Arecibo, a million with ASKAP/MeerKAT (2013), a billion with SKA (2022)

SKA very, very large surveys Key Science Projets that can only be done with the SKA: Redshifts (and HI images) of a billion galaxies Images of 10 billion radio continuum sources Precise study of the nature of Dark Energy Detection and timing of 20,000 pulsars Hard tests of relativity theory Observation of the polarisation of radio sources Only way to study origin and evolution of cosmic magnetic fields and Exploration of the Unknown

Major challenges for getting the SKA built Build it for an "astronomical amount" : a million square metres for 1.5 billion 750 /m 2 telescope construction cost Selection of the best technology: science/cost Site selection Governance structure (financing the 1.5 G ) - competition with other ground-based instruments (30-40 m optical) Construction of Phase 1 (10% of SKA) in 2013 First science with Phase 1 by 2017 Construction of full SKA by 2023

International SKA Project old Roadmap (2006)

International SKA Project last year s Roadmap (2008) your PhDs

SKA project "born global" who is involved? The SKA project was "born global", and has remained so (only truly global ground-based astronomical project) 19 Countries (Europe, North America, Africa, Australia, Asia) 55 Institutes 15 Funding Agencies ~100 FTE engineers and scientists working on SKA R&D around the world on SKA Design Studies and Pathfinders ~150 scientists and engineers actively involved in the international working groups Currently funded SKA R&D (2007-2012) via national and regional projects: 140 MEUR (PrepSKA, Design Studies, Pathfinders)

International SKA Projet old management structure (2005) The SKA project was "born global", and has remained global (only global ground-based astronomical project)

International SKA Projet new management structure -1 Funding agencies & scientific and engineering SKA community

International SKA Projet new management structure - 2 (2008) PrepSKA: Funding Agencies & scientific and engineering SKA community

4 SKA sites proposed in 2005: two were short-listed [Argentina] South Africa Australia [China]

The size of the SKA projected on a random continent

Differents concepts proposed for an SKA station (2005) Need: cheap solution - antennas for 500 EUR/m 2 CHI EUR European: phased array tiles multi-beam AUS Single reflector or Large Number, Small Diameters developpement of hybrid concepts (parabolas with phased array as receiver) USA

SKA reference design - 1 (2007) Enabling technology for SKA construction: Multi-beam phased arrays Core: Aperture Array (tiles) - multi-beam (electronic) 0.3-1 GHz Core and arms: small parabolas with Phased Array Feeds 0.3-10 GHz

SKA reference design -2 Core: Aperture Array - tiles Station: parabolas (12m?) with Phased Array Feed?

Preparing for the SKA in Europe (2005 -.) EC FP6 2005-2009: Design Study (10.4 MEUR EC ) SKADS - Design study of Aperture Arrays EC FP7 2008-2011: Preparatory Phase (5.5 MEUR EC) global PrepSKA Governance (MoA for Agency funding) System design, prototyping of 2 antennas; recrutement of central project team Natl. funding 2009-2011: Aperture Array Verification Program (5 MEUR) EC FP6 Marie Curie: Conferences and Training Courses (bonjour!) MCCT SKADS (0.5 MEUR EC) EC FP7 Marie Curie: Initial Training Network (2009-2013) Path2SKA (4.5 MEUR): 30 PhD projects at 12 institutes will be re-proposed

SKA Design Studies (2005-2009) EC FP6: 38 MEUR total, 10.4 MEUR EC Main objectifs: Construction of EMBRACE, the demonstrator of the european concept for an SKA Aperture Array (installed at Westerbork and Nançay in 2008) R&D towards the adoption of this concept for the SKA Partners: 32 institutes in13 countries (principal: NL, UK, F, I)

SKA Design Studies (2005-2009)

MCCT SKADS (2007-2009) Marie Curie Conferences and Training and Courses on the Square Kilometre Array Design Studies 10 European participating institutes 3 Training Schools: fundamentals and new instruments 30 participants 2 Astronomy workshops: scientific aspects of SKA 25 2 Engineering Workshops: antennas and enabling technologies 25 3 Mixed Workshops 25 + practical training sessions 40 Training Schools: Medicina 2007, Sigüenza 2008, Paris 2009 Practical assignments: spend 3-4 weeks at a participating institute.

SKA preparatory phase: PrepSKA (2008-2011/12) 5.5 MEUR EC obtained over 3 years (will ask for an extra year s funding) Global project funded by EC: partners from all over the world Half the budget is for the recruitment of the core SKA Central Design and Integration Team (CDIT): 15 persons in Manchester Main objectifs: - Memorandum of Agreement (MoA) for SKA construction, "ready for signature " by Funding Agencies - Costed design for full SKA, detailed design for SKA-Phase 1 (10%) - Construction of 2 prototype parabolas Not allowed: more scientific and instrumental studies and simulations

SKA preparatory phase: PrepSKA (2008-2011) PrepSKA Work Packages 1 Management 2 SKA Design (half the budget) 3 SKA sites 4 SKA governance and legal framework 5 SKA procurement and industrial involvement 6 SKA funding model 7 SKA implementation plan

PrepSKA WP2 (SKA Design) - objectifs Primary deliverable: costed design for the SKA, including a detailed system design, and design verification units, for SKA Phase 1 (10% SKA). Primary purpose: integrate this distributed design knowledge into a coherent costed design for the SKA, in preparation for construction of the telescope. This will be achieved by establishing a central engineering program with strong links to regional activities the likely form of the SKA construction model. Central Design and Integration Team (CDIT): 15 persons recruited

Aperture Array Verification Programme: AAVP SKADS Aperture Array technology demonstrator: EMBRACE small (100 sq.m at Westerbork, 80 sq.m at Nançay) certain system parameters not known by end of SKADS (07/2009) Need European post-skads work on Aperture Arrays: AAVP to get the AA concept accepted as viable for SKA Phase-1 and beyond No EC funding possible, need to be funded nationally Discussion on ultimate goals in progress, will determine size Expected funding will not allow real science demonstrator size (X,000 sq.m) Going green: aim for solar energy powered test site on Iberian peninsula

European SKA Consortium: ESKAC encourage, support, and coordinate funding applications for scientific and technical development and operation of the SKA coordinate the participation of Europe in the International SKA Programme and appoint European members for the SSEC

European Roadmaps ESFRI (2006) European Strategic Forum on Research Infrastructures (ESFRI) only 34 projects pre-selected by ESFRI could apply for EC Preparatory Phase; no priorities given Astronomy: E-ELT: 42 m optical telescope SKA

European Roadmaps AstroNet (2008) Science Vision: Scientific Priorities for the next 15-25 years in Europe Infrastructure Roadmap: A plan for the resources needed to make the Science Vision a reality E-ELT is an ESO project, of 1 GEUR (start 2010) SKA is a global project of 1.5 GEUR, in which Europe aims to be in leadership position (start 2012) Phased funding to ensure both are affordable "E-ELT first, then SKA" (and is 10% SKA not enough?) budgets comparable to large space missions, but ESA budget is 400 MEUR/yr will require increased funding in Europe for ground-based astronomy

European Roadmaps AstroNet (2008) Budgets in MEUR/yr Total SKA ESO national E-ELT

Landscape with SKA (2020)