SKA

Objectives

The Square Kilometre Array (SKA) project aims at building a radio-interferometer with a collective area of 1 km2 that will operate at radio frequencies from 50 MHz to 24 GHz. The instrument will be located on two sites, in Australia and South Africa, and the construction is planned in two phases. 10% of the total collective area will be deployed at first (starting from 2020) – SKA1-LOW (50-350 MHz) in Australia and SKA1-MID (350 MHz-15 GHz) in South Africa – with the rest to be deployed in the 2030 timeframe. In addition to its stand-alone mode, SKA will be able to operate jointly with VLBI networks, thus providing very long baselines (several-thousand-kilometer long) with unrivalled sensitivity.

The key questions that SKA will address include (i) the formation of the first black holes and stars during the dark ages of the Universe, (ii) the formation of the first galaxies and their evolution, (iii) strong-field tests of gravity that could challenge the theory of General Relativity, (iv) the origin of cosmic magnetism, and (v) the formation of planets and search for life. With a very flexible design, SKA will also be able to address many other questions.

Identification

• https://www.skatelescope.org/
• https://ska-france.oca.eu
• Coordination : Fabienne Casoli (Paris Observatory)
• Contact Local : Patrick Charlot, LAB

Data

Access to the SKA data will be exclusively through the SKA regional centers (including the European data center which may be distributed over several countries). These regional centers will have responsibility for archiving the SKA data, making them available to the community together with appropriate tools for processing, and to facilitate the production of value-added data and their analysis. About 50 to 70% of observing time in SKA1 will be devoted to Key Science Projects, which are defined as large projects requiring more than 1000 hours of observation (e.g. sky surveys). Proposals for such projects are being studied within the eleven Science Working Groups and two Focus Groups of SKA. Their realization may necessitate developing specific tools and pipelines to meet the desired objectives.

Involvement of OASU

The LAB is involved in the development of SKA both at the instrumental level (definition, design and delivery of electronic systems) and for the SKA-VLBI aspects. Activities along these lines are the following:

• Participation in the design and construction of receivers for bands 4 (2.8-5.2 GHz) and 5 (4.6-13.8 GHz) of SKA1-MID within the DISH consortium, plus the design of receivers for Band B (4-24 GHz) within the WBSPF consortium. The latter is part of the advanced instrumentation envisioned for phase 2. These developments are the subject of contractual activities with the above consortiums.
• Development of tools and pipelines to simulate and optimize observations with SKA1 when operating jointly with VLBI arrays, e.g. the European VLBI Network (EVN) and the planned African VLBI Network (AVN). The objectives targeted with such VLBI observing mode are astrometry and imaging at high resolution and high sensitivity. This activity comes within the framework of the SKA-VLBI focus group.

Collaborations

Due to its scope and uniqueness, SKA is a world-wide project. The observatory will be run by an intergovernmental organization « SKA Observatory » which will replace the present office « SKA Organization » (SKAO), a British legal company located in Jodrell Bank (UK), which was charged with the preparatory phases of the project. At the national level, the « Maison SKA-France », a consortium of research institutes (including the University of Bordeaux) and French industrial companies, joined SKAO in 2018. The Maison SKA-France is also charged to favor synergy between science, technology an industry. As regards SKA-VLBI aspects, the driving force is JIV-ERIC (of which France is a member through CNRS). In particular, developments are carried out in the framework of the H2020 project JUMPING JIVE (of which CNRS through LAB is a partner).