AI and chess have a shared history, from the ‘Mechanical Turk’ to modern-day advances. This talk will cover some part of the story! It will include AlphaZero, a neural network-powered reinforcement learner. Seventy years ago, Alan Turing conjectured that a chess-playing machine could be built that would self-learn and continuously profit from its own experience. The AlphaZero system passed this milestone. How did it do it? What did it learn from its experience and how did it encode it? Did it learn anything like a human understanding of chess, in spite of having never seen a human game? We will partially answer some of these fascinating questions in the talk.

Endowing advanced imaging instruments such as telescopes and medical scanners with an acute vision that enables them to probe the Universe or human body with precision is a complex mathematical endeavour. It requires solving challenging inverse problems for image formation from observed data. In this talk, we will dive into this field of computational imaging, and its specific application in radio astronomy, where algorithms are currently facing a multi-faceted challenge for the robust reconstruction of images at extreme resolution and dynamic range, and from extreme data volumes. We will discuss advanced algorithms at the interface of optimisation and deep learning theories, from SARA, an optimisation algorithm propelled by handcrafted priors, to AIRI, plug-and-play algorithm relying on learned denoisers, and a newborn network series approach R2D2. We will also discuss ongoing work for the transfer of such algorithms to medical imaging. Last but not least, we will take a few seconds to unveil Star Wars hidden facts and misconceptions.

Accurate polarimetry requires knowledge of the Electric Vector Position Angle (EVPA) of at least one calibrator source – necessary for circularly polarized systems like the VLA and VLBA, and useful for linearly polarized ones like MeerKAT, the SKA, and the ngVLA. The preferred polarization calibrator is the quasar 3C286, which for decades was believed to have an EVPA of 33 degrees. The advent of MeerKAT polarimetry has indicated the EVPA of 3C286 is significantly less than 33 degrees, and changes rapidly with decreasing frequency. Complicating the situation is the effect of ionospheric Faraday rotation, which becomes significant below 2 GHz. In this presentation, Dr Perley describes their efforts to accurately determine the EVPA of 3C286 with both MeerKAT and the VLA, utilizing the Moon, Venus, and Mars as polarization angle calibrators.

Much of the evolution of galaxies before they are assimilated into clusters takes place in groups where AGN feedback has the greatest impact on galaxy formation and evolution. On the other hand, clusters are the largest gravitationally-bound structures in the Universe, with their baryonic mass being distributed between the constituent galaxies and the ionized plasma of their intra-cluster medium (ICM). As such, radio observations of galaxy clusters are powerful tools for the detection of diffuse cluster-scale synchrotron emission, which carries information about the cluster formation history. In the first part of this talk, I will summarize results from studies of the central brightest group early-type galaxies (BGEs) of an optically selected, statistically complete sample of 53 nearby groups (within 80 Mpc; CLoGS sample), observed in radio 235/610 MHz (GMRT), CO (IRAM/APEX) and X-ray (Chandra and XMM-Newton) frequencies examining the jet energetics impact on the intra-group gas, the balance between hot and cold gas and the AGN activity and star formation in groups. In the second part, I will present an overview of the MeerKAT’s Galaxy Cluster Legacy Survey (MGCLS), a program of long-track observations of 116 galaxy clusters at 1.28 GHz spread out over the Southern sky, focusing on the diffuse emission detected in galaxy clusters highlighting a few significant examples to reveal both the much-improved radio images compared to previous observations, as well as new discoveries that open up new areas of investigation in cluster formation and evolution.

In the last 40 years, astronomers have charted the 3D position of galaxies in the Universe. With the recent Sloan Digital Sky Survey (SDSS) and the recent Dark Energy Spectroscopic Instrument (DESI) survey, a much clearer picture is arising of the matter distribution across the Universe. These measurements confirm the Lambda-CDM cosmology model even though some tension in the model still exists, and need to be understood. I will give a summary of the recent progress and understanding, as well as give an outlook on future projects. In particular, I will present the required instrumental developments needed particularly in robotics to make the next-generation spectroscopic surveys possible

The South African MeerKAT telescope has produced numerous spectacular results in the four years that have passed since its inauguration. This has largely been the result of both the unprecedented imaging capabilities of the instrument, as well as the significant amount of observing time that has been invested in community and observatory-led large survey programs. Prof Heywood will present some results from three such projects that he has been lucky enough to be involved in, covering extragalactic deep fields, observations of an unusual pulsar, and concluding with some radio views of the centre of our own Galaxy.

Compact radio sources twinkle, or scintillate, due to radio wave scattering from small-scale fluctuations in electron density in the interstellar medium (ISM). The scattering manifests as a variety of observational phenomena, that give clues as to the nature of the scattering ‘screens’. However, despite their apparent ubiquity, the underlying physics of the screens is not yet well understood. In this talk I summarise some results, mainly from observations of scintillating quasars over the past 25 years, and outline some future directions for elucidating the nature of the scattering plasma structures in the ISM.

In recent weeks, NASA announced as its priority 1 flagship mission a Uranus Orbiter and Probe. In this talk, Prof de Pater will attempt to provide a summary of their present state of knowledge of Uranus and Neptune and their rings systems as derived from multi-wavelength observations, in particular data obtained with HST, Keck, VLT, ALMA, and the VLA. Which questions may a mission answer that we may not be able to answer from the ground or JWST?

Understanding galaxy formation and evolution is one of the key goals of astronomical research. With roughly half of the galaxies in the local Universe residing in dense environments, it is therefore important to study the effects of environment on galaxy evolution. It has been known for several decades that galaxy clusters harbour a relatively large fraction of early-type galaxies. This suggests that dense environments can cause the premature quenching of star formation. Several environmental processes have been suggested to contribute to this, such as ram pressure stripping, starvation, violent fly-bys, and tidal interactions. However, the relative importance of these mechanisms, and how exactly they lead to the quenching of star formation, is still poorly understood.

Typically distributed in an extended disc, atomic gas has long served as an excellent tracer for environmental processes. However, it is the molecular gas that is the direct fuel for star formation. Therefore, any direct effects of the cluster environment on the more tightly bound and centrally located molecular gas would have strong implications for galaxy evolution in dense environments.

In this talk Dr Zabel will discuss studies of the molecular gas in galaxies in the nearby Fornax cluster, and will close with some early results from the recently published paper ‘VERTICO: The Virgo Environment Traced in CO Survey’

SRG X-ray Orbital Observatory was launched to the second Lagrange point of the Sun-Earth system (1.5 million km from the Earth) on July 13th, 2019. It constructed four full maps of the sky and detected in X-rays more than 2 million quasars, 50 thousand clusters of galaxies, half a million stars with hot coronae, supernovae remnants, accreting neutron stars, and stellar mass black holes in our Galaxy.

Many X-ray sources demonstrate strong variability. For example, we have already detected more than 60 TDEs (Events of the Tidal Disruption of the stars in the vicinity of supermassive black holes in the centres of distant galaxies).

The article examines critical success factors in high technology projects by comparing the Square Kilometre Array, the Pebble Bed Modular Reactor and the Reactor Conversion Project in the context of a historical view of South African technology policy. These three complex endeavours illustrate rather well what mistakes can be made in the conceptualising and in the execution of such projects. The article argues that the confluence of a range of diverse factors such as sufficient prototyping, understanding and balancing political stakeholders, getting the organisational culture right and managing ambitions and aspirations are necessary for success to be achieved.

The search for technosignatures - remotely observable indicators of advanced extraterrestrial life - addresses one of the most profound questions in science: are we alone in the universe as intelligent life? The Breakthrough Listen program is leading the most concerted search for extraterrestrial intelligence (SETI) effort to-date through radio and optical surveys of nearby stars, nearby galaxies and the Milky Way galactic plane, thus representing the best chance the human race has ever had to detect a technosignature. Recently, Breakthrough Listen has partnered with the SETI Institute to develop commensal SETI search capabilities on some of the most sensitive radio inteferometers, including the Allen Telescope Array (ATA), the Very Large Array (VLA) and MeerKAT. Interferometric radio telescopes have the advantage of providing a larger field of view, maximizing the SETI survey speed. In this talk, we will present the latest updates on these surveys and conclude with a refreshed outlook on SETI search using next generation telescope facilities.

The Shapley Supercluster is the largest gravitationally bound supercluster in the nearby Universe, where cluster mergers and group accretion are taking place at the present epoch. Given the broad mass range of the clusters and groups in this region of the sky, this is an ideal place to study the signatures of minor mergers in the radio band, which have been so far unaccessible due to the limitations of the past generation of radio interferometers. In this talk new results on the central region of the Shapley Supercluster as revealed by ASKAP and MeerKAT are shown. The observations show that even minor mergers are spectacular, and can give rise to Mpc scale diffuse radio emission in galaxy clusters, as well as radio features which bear invaluable information on the formation of large scale structures in the Universe.

Dr. Bernard ‘Bernie’ Fanaroff takes us on a retrospective journey of his collaborative work on the classification of radio galaxies, and his account of the history of the SKA, South Africa and the becoming of the MeerKAT telescope in South Africa.

Dr. Bernard ‘Bernie’ Fanaroff takes us on a retrospective journey of his collaborative work on the classification of radio galaxies, and his account of the history of the SKA, South Africa and the becoming of the MeerKAT telescope in South Africa.

Current and future radio telescopes like LOFAR, MeerKAT and the SKA produce extremely large data sets. Making scientific products from these large data sets is challenging but of high importance, and allow us to analyze our Universe more distant, at earlier times and with more detail than ever. Ideally, observatories make products available that are (science-) ready for astronomers to look at, but this requires efficient and automated algorithms that process the data in scientifically credible ways. In my talk I will focus on this kind of processing algorithms, and describe a few novel algorithms that I have work on, including AOFlagger, WSClean and DP3-DDECal. Together, these allow us now to make 100,000 by 100,000 pixel images with LOFAR, and prepare use for LOFAR2 and the SKA.