Canada and the SKA from 2020 - 2030

The Square Kilometre Array (SKA), an exciting new world observatory that will enable transformational science at metre and centimetre wavelengths for years to come, is rapidly becoming reality. The SKA will be built in two phases, with the first phase (SKA1) representing ~10% of the full facility (SKA2). The SKA1 Design Baseline development is almost complete, and construction is set to begin early in the next decade. When constructed, it will be the largest and most powerful general-purpose radio telescope operating from 50 MHz - 15 GHz for years to come. Scientific and technological participation in the SKA has been identified as a top priority for the Canadian astronomical community for almost twenty years. This white paper advocates for Canada’s continued scientific and technological participation in the SKA project, focussing on Canadian prospects for SKA1 from 2020-2030.<br> <br> SKA1 is poised to make fundamental advances across a broad range of fields by virtue of its combination of sensitivity, angular resolution, imaging quality and frequency coverage. SKA1 scientific goals align well with the strengths of Canadian researchers. Canada is a world leader in studies of pulsars, cosmic magnetism and transients, as well as in low-frequency cosmology. Our multi-wavelength expertise in galaxy evolution, multi-messenger astronomy and planetary system formation – in which radio observations play a critical role – is also a key strength. The Canadian community therefore has the potential to carry out important PI science with SKA1, as well as to play world-leading roles in a number of the transformational Key Science Projects (KSPs) that are anticipated to take up the majority of available telescope time. An examination of the KSP leadership opportunities afforded by a decade of full operations implies that a 6% participation in the SKA1 Design Baseline is well-matched to Canadian scientific capacity and ambitions.<br> <br> Canada is a leader in technological development for the SKA through effective partnerships between universities, the National Research Council (NRC) and industry. Our key SKA1 technological capabilities include the design and fabrication of correlators and beamformers, digitisers, low-noise amplifiers, signal processing, and monitor &amp; control. These technologies provide a suite of possible in-kind contributions to offset construction costs for good return on the capital investment required to participate in SKA1 at a level commensurate with our scientific ambitions. Canada also has the computing platform and archive development expertise to make important contributions to the SKA Regional Centre (SRC) network that will deliver global SKA1 scientific computing capability. A Canadian SRC would leverage our national compute strength to provide processing, storage, and user support tailored to Canadian SKA1 needs while also fulfilling our SKA1 participation requirements.<br> <br> Canadian contributions to the SKA now span two decades, marked by scientific and technological leadership that persists today within a vibrant metre and centimetre-wave radio community. SKA1 is happening now. Canada at last has the opportunity to reap the scientific benefits of our contributions, while an early commitment to construction would maximize our impact on this phase and our technological benefits as well.<br> <br> The 2020 Canadian Long-Range Planning process (LRP2020) will determine the future of the SKA in Canada for the next decade and beyond. We make the following recommendations: Canada should participate in the construction and operations phases of SKA1. SKA1 Design Baseline construction, operations and a staged technology development program should be funded at a 6% level, commensurate with Canadian scientific ambitions. This commitment is estimated to cost $160M CAD over the period 2021-2030. Canada should participate in the SKA regional centre (SRC) network to ensure community access to the processing, storage and user support required to scientifically exploit SKA1. The cost of this participation at a level commensurate with Canadian scientific ambitions, and in accordance with SRC network guidelines, is estimated to be $45M CAD over the period 2021-2030 in addition to construction and operations funding. To meet its SKA1 compute needs, Canada should leverage its established strength in scientific computing platforms and archive development by hosting a Canadian SRC. The membership model through which Canada participates in the intergovernmental organisation (IGO) that will build and operate SKA1 should provide full scientific and technological access as well as leadership rights for Canadian researchers and industry. An agreement for Canadian participation in the IGO should be finalized as early as possible in the next decade in order to maximize our impact on the construction phase as well as to maximize opportunities for technological tender and procurement.