|Donald Kurtz |
Asteroseismology across the HR diagram
Asteroseismology has grown from its beginnings three decades ago to a mature field teeming with discoveries and applications. This phenomenal growth has been enabled by space photometry with precision 10-100 times better than ground-based observations, with nearly continuous light curves for durations of weeks to years, and by large scale ground-based surveys spanning years designed to detect all time-variable phenomena. The new high precision data are full of surprises, deepening our understanding of the physics of stars. This talk is based on my in-press Annual Reviews of Astronomy and Astrophysics invited review now available on arXiv. It provides an introduction to asteroseismology and brief highlights of the many types of pulsating stars.
|Francoise Combes |
Active Galactic Nuclei (AGN) fueling and feedback
The feeding of super-massive black holes in galaxies is a problem that can be addressed now with high spatial resolution in nearby AGN. Dynamical mechanisms are essential to exchange angular momentum and drive the gas to the center.
While at 100pc scale, the gas is sometimes stalled in nuclear rings, recent observations reaching ~10pc scale (or 50mas), inside the sphere of influence of the black hole, may bring smoking gun evidence of fueling, within a randomly oriented nuclear molecular disk. Observations of AGN feedback will be presented, togetherwith the suspected responsible mechanisms. Molecular outflows are frequentlydetected in active galaxies, and the ALMA and NOEMA resolution gives clues to their origin, either radiative of kinetic AGN mode, or starburst. When driven by AGN with near escape velocity, these outflows are therefore a clear way to moderate or suppress star formation.
|Lina Canas |
IAU Office for Astronomy Outreach: Building Bridges Through Astronomy Dissemination and International Cooperation
From the International Year of Astronomy in 2009 – The Universe Yours to Discover; to IAU 100 Years Celebrations in 2019 – Under One Sky, through the IAU Office for Astronomy Outreach (IAU OAO) the IAU engages the public in astronomy through access to astronomical information and communication of the science of astronomy. The IAU OAO work focuses on building bridges between the IAU and the global astronomy community of outreach professionals, educators, amateur and professional astronomers, and the public. Through international cooperation, we envision making astronomy a science that is accessible to all. In this talk, I will present the IAU outreach activities’ ten-year legacy, implemented in cooperation with the IAU National Outreach Coordinators (NOCs) present in over 120 countries worldwide. With the IAU Strategic Plan for this decade, the IAU has established several actions for communication, outreach, and public engagement, and I will address some of the initiatives carried out by the office with a particular emphasis on our initiatives in Africa.
|Alemiye Mamo Yacob |
East Africa’s potential for astronomical investment and development.
The economic growth and investment in East Africa region have been increasing in the past years and the region is becoming one of the fastest growing regions in Africa. The economy’s rapid growth is being driven by sustained public spending on infrastructure, improved agricultural performance, and deeper regional economic integration. However, there are a number of developmental challenges that still exist in the region that impacts heavily on the lives and livelihoods of people, and hinders regional integration and trade. The COVID-19 pandemic, locust swarms, draught and famine, aggravate the challenges more and it needs an alternative approach to combat and sustained the economic development in the region. Economic diversification and investment in astronomy tourism and observational astronomy can be viewed as positive initiatives and alternative approaches for the region’s economic development. Because of its proximity to the equator, which allows it to observe both the southern and northern hemispheres of the sky, as well as a number of high plateau mountains with dry weather conditions, the east African region is a potential location for investment in observational astronomy. The region also has vast cultural and astronomical heritages, as well as untapped dark skies, which can help the region’s asto-tourism development. As a result, the talk will concentrate on the developmental aspects of astronomy investment in East Africa, as well as current activities and successes in the region.
|ROY MAARTENS |
Cosmology with MeerKAT and SKAO
I will describe the exciting prospects for advances in cosmology with the SKAO-MID radio telescope array. 64 of the 197 dishes are already operating – in the form of the South African precursor array, MeerKAT. MeerKAT is being used to help develop techniques that will be used for cosmology with the full SKAO array. SKAO will open a new window on the cosmos and cover larger cosmic volumes than ever before. Optical surveys by telescopes like Euclid and the Rubin Observatory (LSST), in combination with surveys by SKAO and HIRAX in the radio band, promise to provide excellent precision in measuring Dark Energy and Dark Matter. In addition, SKAO surveys will deliver a new capacity to make tests of the foundations of our model of the Universe.
|Michelle Lochner |
Anomaly Detection in Astronomical Data using Machine Learning
The next generation of telescopes such as the SKA and the Vera C. Rubin Observatory will produce enormous data sets, far too large for traditional analysis techniques. Machine learning has proven invaluable in handling large data volumes and automating many tasks traditionally done by human scientists. In this talk, I will discuss how machine learning for anomaly detection can help automate the process of locating unusual astronomical objects in large datasets thus enabling new cosmic discoveries. I will introduce Astronomaly, a general purpose framework for anomaly detection in astronomical data using active learning and overview some recent results.
|Michael Backes |
The Africa Millimetre Telescope project in Namibia
The first image of the shadow of the central black hole in the radio galaxy Centaurus A by the Event Horizon Telescope (EHT) opened a new window of research into active galactic nuclei (AGN) as well as into black holes. Soon it became clear that for improved image quality but particularly also temporal resolution, additional telescopes will need to be added to the EHT network of telescopes. The Africa Millimetre Telescope (AMT) will close the gap by being the first telescope in Africa to observe at mm wavelengths. Beyond VLBI observations within the EHT, the AMT will also operate as single-dish telescope, whose scientific program will include flux monitoring of AGN, amongst others. The AMT is co-led by Radboud University in the Netherlands and the University of Namibia and from its inception, a social impact plan is one of the central components of the project.This presentation will outline the different aspects of the AMT project.
Astronomy education for African growth: Examples from East-Africa
Education and its contribution to science, technology, and innovation is a key for combating poverty in the long term. Education is also a key for empowering girls and women, which is fundamental for achieving the
United Nations (UN) Sustainable Development Goals (SDGs) and 2030 UN agenda. Astronomy is a powerful tool to promote education and science but is also one of the leading sciences for bringing strong technological developments and innovation. The status of astronomy in Africa changed significantly over the past years, becoming an emerging field across the continent, and never before it was more possible to use astronomy for development as it is nowadays. Using as an example different activities carried out in Ethiopia and East Africa, this talk will summarise the importance of astronomy education and its contribution to African growth for the benefit of our all society.
|Zouhair Benkhaldoun |
Peering into space with the Morocco Oukaïmeden Observatory
We present in this contribution, some of the most productive themes in terms of publication and PhD training. The story first began with helioseismology and astronomical site qualification studies and then continued with the small solar system bodies, variable stars and exoplanets. The observatory has finally invested recently in the space field with the consolidation of the Space Weather field to finally invest in the field of monitoring satellites and space debris in general. We will review all these advances which can be inspiring for other communities in the African continent and beyond.
|Lerothodi Leeuw |
An Update on the African Cosmology and Astrophysics Strategy
We will give an update on the African Cosmology and Astrophysics Strategy and discuss options and opportunities for participation (See, https://africanphysicsstrategy.org).
|Carolina Odman |
Translating science, people first.
In this age of lack of trust in science, education is critical to building generations of scientifically literate citizens able to make the right decisions for the planet’s well being. This is however not an option when the language of instruction of science is a learners’ and teachers’ second or third language. This is the case in many emerging and developing countries, where English is the language in which science is taught. A lot of research has been carried out in multilingual primary education, and its benefits are well documented. There is still a gap however, not just for secondary education, but specifically for scientific subjects, which may not have suitable language in learners’ mother tongue. We have set up a collaboration between scientists, linguists and education specialists to try to develop suitable scientific language in South Africa’s official languages. We have learnt that a purely vocabulary-oriented approach is insufficient to develop language that is adopted by communities. We have learnt that the wealth of formulations and constructs in indigenous languages can be adopted to describe scientific knowledge. We have also found that indigenous knowledge and the scientific knowledge it carries is a good avenue for such language development. To succeed in this enterprise means working at the interface between linguistics, education and science. We hope that when everyone can talk science in their mother tongue, science will truly become a public good.
|Sonal Asgotraa |
Astrostays: Community-Led Astro-tourism
Astrostays is a community-led astro-tourism model that places sustainable tourism and community development at its core. The project aims to empower local communities by diversifying economic streams and creating new opportunities for livelihood creation through astro-tourism. This model is also an innovative form of experiential tourism that generates economic benefits directly for remote regions that have access to clear night skies while creating unique and engaging experiences for travellers.
|Kenda Knowles |
Viewing Clusters with MeerKAT
Galaxy clusters are the largest known gravitationally bound structures, and lie at the intersection of cosmology and astrophysics. In the radio, some galaxy clusters are found to host large-scale diffuse synchrotron emission. As this synchrotron emission is caused by high energy particles spiralling in the cluster magnetic field, this diffuse emission is critical for understanding the non-thermal physics and magnetic fields in cluster environments, aspects difficult to probe at other wavelengths. I will discuss some of the work I’ve been doing with MeerKAT to study this emission, specifically regarding two projects: the MeerKAT Exploration of Relics, Giant Halos, and Extragalactic Radio Sources (MERGHERS) survey and the MeerKAT Galaxy Cluster Legacy Survey (MGCLS).
|Unathi Kondile |
Boosting African Astronomy in the Media
Go to any local library in South Africa and ask for books on Science Journalism. The results are more than likely to be nil. You will be directed to the Social Sciences section where hoards of books on Stargazing are stacked. Yet, mankind’s fascination and interested in Astronomy and Space as whole seems to be on the rise. We are seeing international news reports of billionares jetting off to Space and the advent of commuter space travel becoming a reality. The media, through space-mission or journey films has also piqued human curiosity on what actually lies around in the galaxy. For example, Moonfall and Don’t Look Up being the latest film additions to this ever expanding genre of speculative films that do not necessary reflect the scientific realities. What do we have here in South Africa and Africa as a whole that expands public curiosity of space ongoings? Where are the short films on Space? Children’s book’s on astronomy? African Science Magazines? Science newspaper sections? What creates this dearth of science content in mainstream press and broadcasting in Africa? This paper on “Boosting African Astronomy in the Media” presents a science media production overview as well as posits possible ways in which African scientists can get their work “out there” to the layman outside the sciences. I further explore what can be done at a tertiary level to ensure that journalism schools can produce a cohort of journalists that are adequately skilled to write about the sciences. African Science Stars is also embarking on a series of citizen journalist workshop whereby in which we upskill Astronomy and Space Science students with basic journalism skills
|Maram KAIRE |
L’ASTRONOMIE AFRIQUE, the first French-speaking webzine of the African continent
Astronomy is a science that is increasingly fascinating on the African continent. This can be justified by the important astronomical heritage transmitted, generations after generations, for centuries, and has through a strong presence of the stars in the daily lives of peoples and different African cultures. Today, we are witnessing a multiplication of development and popularization initiatives around astronomy in order to respond to the curiosity of populations for the sciences of the universe but also a dynamic collaboration for research in astronomy. However, one of the major obstacles remains access to information in certain places and the regular dissemination of appropriate actions from African soil. Faced with the difficulty of providing fans of the sky in Africa with recent books and paper magazines, the answer will be provided by the high rate of digital penetration on the continent. In 2020, the Astronomical Society of France (SAF) initiated, in partnership with the Senegalese Association for the Promotion of Astronomy (ASPA), the establishment of the first Webzine in French, accessible free online. The project was joined very quickly by several partners in order to give birth to ASTRONOMY AFRICA, a real showcase of astronomy in full swing in Africa.
|Renee Kraan-Korteweg |
What can MeerKAT tell us about galaxy overdensities hidden behind the Milky Way
Galaxies are distributed in a cosmic web consisting of high-density clusters and galaxy groups within walls and filaments surrounding vast low-density regions. The galaxy overdensities exert gravitational perturbations on the smoothly expanding Universe, which can induce bulk flows over cosmologically large volumes. In describing how to trace such galaxy agglomerations and derive their mass, emphasis will be given to the “Zone of Avoidance” (ZOA), the region in the sky that is obscured by the dust and stars of our own Milky Way leaving a broad gap in the otherwise well-charted extragalactic sky. Structures such as the infamous Great Attractor, the Local Void (voids act as repellers), and the recently discovered Vela Supercluster, remain poorly mapped. However, their masses are crucial to reconcile the decade-long cosmological controversy about the amplitude and volume within which such bulk flows arise. While many long-term multi-wavelengths efforts succeeded in reducing the ZOA-gap, its innermost part still remains uncharted. Only the 21cm-line emission of gas-rich galaxies does prevail. The powerful MeerKAT can help to bridge that gap. I will end with preliminary results from surveys undertaken with MeerKAT revealing a tantalising first glimpse of hints galaxy walls across part of the inner Milky Way that was deemed impenetrable.
|Marie Korsaga |
Baryonic to Halo Mass Relation of galaxies
One of the most active areas of research of the last decade is undoubtedly the study of the effects of baryons on the observed dynamics of galaxies. This particularly led to the establishment of some fundamental scaling relations, which characterise the dependence of the abundance of baryons on the properties of galaxies’ dark matter (DM) haloes. Among these fundamental relations, the stellar–to-halo mass relation appears to be one of the most investigated.In this talk, I will present the less-explored cold baryons-to-halo mass relation constructed with 180 observed spiral and irregular nearby galaxies, selected from the SPARC and LITTLE THINGS databases. I will discuss how these relations were constructed using the Dekel-Zhao and the Navarro-Frenk-White profiles to constrain the DM halo of the galaxies and how we investigate the scaling relations between the cold baryons and DM halo parameters.Finally, at the end of the presentation, I will present some of the recent outreach activities that I have either led or contributed to, with the goal of developing astronomy and space sciences in West Africa.