Very Long Baseline Interferometry (VLBI) offers unrivalled resolution in studies of celestial radio sources. The subjects of interest of the IAU Symposium No. 356, the Active Galactic Nuclei (AGN) of all types, constitute the major observing sample of modern VLBI networks. At present, the largest in the world in terms of the number of telescopes and geographical coverage is the European VLBI Network (EVN), which operates under the open sky policy via peer-reviewed observing proposals. Recent EVN observations cover a broad range of science themes from high-sensitivity monitoring of structural changes in inner AGN areas to observations of tidal eruptions in AGN cores and investigation of redshift-dependent properties of parsec-scale radio structures of AGN. All the topics above should be considered as potentially rewarding scientific activities of the prospective African VLBI Network (AVN), a natural scientific ally of EVN. This contribution briefly describes the status and near-term strategy for the AVN development as a southern extension of the EVN-AVN alliance and as an eventual bridge to the Square Kilometre Array (SKA) with its mid-frequency core in South Africa.
South Africa has played a leading role in radio astronomy in Africa with the Hartebeesthoek Radio Astronomy Observatory (HartRAO). It continues to make strides with the current seven-dish MeerKAT precursor array (KAT-7), leading to the 64-dish MeerKAT and the giant Square Kilometer Array (SKA), which will be used for transformational radio astronomy research. Ghana, an African partner to the SKA, has been mentored by South Africa over the past six years and will soon emerge in the field of radio astronomy. The country will soon have a science-quality 32m dish converted from a redundant satelli…
The development of astronomy and space science in Africa has grown significantly over the past few years. These advancements make the United Nations Sustainable Development Goals more achievable, and open up the possibility of new beneficial collaborations.
Astronomy plays a major role in the scientific landscape of Namibia and Southern Africa. Considerable progress has been achieved scientifically as well as in terms of human capacity development in the field. In all wavelength regimes accessible with ground-based instruments, the largest of those instruments are situated in Southern Africa: MeerKAT, the Southern African Large Telescope, and the High Energy Stereoscopic System. Because of the excellent observing conditions from Namibian soil, further large-scale projects such as the Cherenkov Telescope Array considered sites in Namibia and the A…
The Mozambique Radio Astronomy Observatory (MRAO) will be a first milestone towards development of radioastronomy in Mozambique. Development of MRAO will constitute a preparation step towards participation in the upcoming Africa VLBI Network and the Square Kilometer Array project. The MRAO first antenna is planned to serve as a capacitation and training facility and will be installed after the conversion of a 7-meter telecom dish in South Africa. Therefore, this first radiotelescope design has to comply with local spectral and environmental constraints. Furthermore, power availability and long…
Africa has amazing potential due to natural (such as dark sky) and human resources for scientific research in astronomy and space science. At the same time, the continent is still facing many difficulties, and its countries are now recognising the importance of astronomy, space science and satellite technologies for improving some of their principal socio-economic challenges. The development of astronomy in Africa (including Ethiopia) has grown significantly over the past few years, and never before it was more possible to use astronomy for education, outreach, and development as it is now. Ho…
From Timbuktu to SKA: Who owns the Astronomy knowledge Africa produces?
North-West University（西北大学）；Centre for Higher Education Professional Development (CHEPD)（高等教育专业发展中心）；The Education and Human Rights in Diversity Research Unit (Edu-HRight)（教育与人权多样性研究单元）；Centre for Space Research（空间研究中心）；National Institute for Theoretical and Computational Sciences (NITheCS)（理论与计算科学国家研究所）
In the African continent, South Africa has world-class astronomical facilities for advanced radio astronomy research. With the advent of the Square Kilometre Array project in South Africa (SA SKA), six countries in Africa (SA SKA partner countries) have joined South Africa to contribute towards the African Very Long Baseline Interferometry (VLBI) Networks (AVN). Each of the AVN countries will soon have a single-dish radio telescope that will be part of the AVN, the European VLBI Network, and the global VLBI network. The SKA and the AVN will enable very high sensitivity VLBI in the southern hem…
Extending the SKA Across Africa: The Case for a Continental African VLBI Network
The University of Manchester（曼彻斯特大学）；University of Bristol（布里斯托大学）；University of Leeds（利兹大学）；National Astronomical Observatories Japan（日本国立天文台）；Copperbelt University（铜带大学）；Ghana Atomic Energy Commission（加纳原子能委员会）；University of South Africa（南非大学）；Institute of High Energy Physics, Chinese Academy of Sciences（中国科学院高能物理研究所）；University of the Witwatersrand（威特沃特斯兰德大学）；Joint Institute for VLBI ERIC（甚长基线干涉测量欧洲研究基础设施合作组织）；ASTRON, Netherlands Institute for Radio Astronomy（荷兰射电天文研究所）；University of Science and Technology of China（中国科学技术大学）；Shanghai Astronomical Observatory, Chinese Academy of Sciences（中国科学院上海天文台）；Technical University of Kenya（肯尼亚科技大学）；Chalmers University of Technology（查尔姆斯理工大学）；STFC RAL Space, Rutherford Appleton Laboratory（STFC拉瑟福德阿普尔顿实验室空间部）；National Research Institute of Astronomy and Geophysics (NRIAG)（国家天文地球物理研究所）
The advent of international wideband communication by optical fibre has produced a revolution in communications and the use of the internet. Many African countries are now connected to undersea fibre linking them to other African countries and to other continents. Previously international communication was by microwave links through geostationary satellites. These are becoming redundant in some countries as optical fibre takes over, as this provides 1000 times the bandwidth of the satellite links. In the 1970's and 1980's some two dozen large (30 m diameter class) antennas were built in variou…
Ghana Radio Astronomy Observatory（加纳射电天文台）；Ghana Space Science and Technology Institute（加纳空间科学与技术研究所）；University of California, Santa Cruz（加州大学圣克鲁兹分校）；Kwame Nkrumah University of Science and Technology（克瓦米·恩克鲁玛科技大学）；South African Radio Astronomy Observatory（南非射电天文台）
Advances in astronomy are intimately linked to advances in digital signal processing (DSP). This special issue is focused upon advances in DSP within radio astronomy. The trend within that community is to use off-the-shelf digital hardware where possible and leverage advances in high performance computing. In particular, graphics processing units (GPUs) and field programmable gate arrays (FPGAs) are being used in place of application-specific circuits (ASICs); high-speed Ethernet and Infiniband are being used for interconnect in place of custom backplanes. Further, to lower hurdles in digital …
It was decided in May 2012 that the Square Kilometre Array (SKA) will be built in Africa and Australia, two Southern Hemisphere continents. Here we discuss the plan for SKA design and construction, and how New Zealand radio astronomers can participate in this project and contribute to astronomy and astrophysics research. Geodesy and the study of tectonic plate motion is another important area of research for New Zealand radio astronomy to contribute to. As New Zealand is located at the boundary between two colliding tectonic plates (Australian and Pacific) and most of geological activity in Ne…
Radio astronomy and Space Infrastructures in the Azores have a great scientific and industrial interest because they benefit from a unique geographical location in the middle of the North Atlantic allowing a vast improvement in the sky coverage. This fact obviously has a very high added value for: i) the establishment of space tracking and communications networks for the emergent global small satellite fleets ii) it is invaluable to connect the radio astronomy infrastructure networks in Africa, Europe and America continents using Very Large Baseline Interferometry (VLBI) techniques, iii) it al…
After a decade of design and construction, South Africa's SKA-MID precursor MeerKAT has begun its science operations. To make full use of the widefield capability of the array, it is imperative that we have an accurate model of the primary beam of its antennas. We have taken available L-band full-polarization 'astro-holographic' observations of three antennas and a generic electromagnetic simulation and created sparse representations of the beams using principal components and Zernike polynomials. The spectral behaviour of the spatial coefficients has been modelled using discrete cosine transf…
