Radio Astronomy

Research

Research interests

The University of Pretoria’s astrophysics research group was started in January 2018 with a primary focus in radio astronomy and major facilities such as MeerKAT, the Square Kilometre Array, and the Event Horizon Telescope. The group pursues science themes that cover a wide range of spatial and energy scales, with a particular focus on high angular resolution radio astronomy. A number of group members specialised in the technique of Very Long Baseline Interferometry (VLBI), which combines signals from radio antennas spread across to the globe to form a single, Earth-sized telescope.

UP astrophysics is particularly interested in supermassive black holes, when they come in pairs, how black holes and their host galaxies (co)evolve. For more detail on this, visit our research page. If you are interested in studying astrophysics at UP, look at our student opportunities or undergraduate programme pages.

11-05-2020 - Solving the mystery of X-shaped radio sources with MeerKAT

10-04-2019 - Astronomers (including UP) capture first image of a black hole

Members

Group Members

Group Leader

Prof Roger Deane
Associate Professor
Research interests: Binary supermassive black holes, strong gravitational lensing, wide-field VLBI surveys, black hole shadow imaging with the Event Horizon Telescope, radio interferometry techniques, high-redshift galaxies
Teaching: Observational astronomy (PHY 300); Computational Physics (Honours)
Contact: roger.deane_at_up.ac.za
Location: 5-73, Natural Sciences I

Postdoctoral Researchers

Dr Kshitij Thorat
IDIA Postdoctoral Fellow
Research interests: My research revolves around extra-galactic radio sources: their life-cycles, morphology and their impact on their surroundings. I am involved in making fully automated data reduction, imaging and calibration pipelines for telescopes like MeerKAT! Finally, I am very interested in the application of Machine Learning techniques to solving problems in radio astronomy.
Teaching: Lecturer for PHY 210 Astronomy for physicists
Contact: thorat.k [at] gmail.com
Location:: 5-70 Natural Sciences 1, University of Pretoria

Dr Jack Radcliffe
SARAO Postdoctoral Fellow
Other affiliations: University of Manchester
Research interests: Galaxy evolution as traced via radio surveys. AGN feedback and wide-field VLBI enthusiast. Also dabbles in radio interferometric calibration techniques
Teaching: Lecturer for PHY 700 Radio Astronomy and the Unit 4 of the Development in Africa with Radio Astronomy programme
Contact: jack.radcliffe [at] up.ac.za / jack.radcliffe [at] manchester.ac.uk
Location: 5-70, Natural Sciences 1, University of Pretoria
Webpage: www.jb.man.ac.uk/~radcliff/

Dr Iniyan Natarajan
Postdoctoral Fellow
Other affiliations: Rhodes University / SARAO
Research interests: High resolution (VLBI) observations of supermassive black holes and active galactic nuclei (AGNs), development of simulation and calibration algorithms for radio interferometry, and application of probability theory in novel ways to the analysis of astronomical data.
Contact: iniyannatarajan [at] gmail.com
Location: Based at the Radio Astronomy Research Group (RARG) at the South African Radio Astronomy Observatory (SARAO) in Cape Town

PhD

Charissa Button
Advisor(s): Prof. Roger Deane
Research interests: galaxy clusters, particularly looking at neutral hydrogen and strong lensing models. Project title: MeerKAT galaxy cluster lens: Strong lensing magnification models and Omega HI constraints in a survey of galaxy clusters
Contact: charissa [at] imago-web.co.za
Location: 5-73 Natural Sciences 1, University of Pretoria

Tariq Blecher
Other affiliations: Rhodes University / SARAO
Advisor(s): Prof. Roger Deane
Research interests: I work in the overarching field of galaxy formation and evolution. My subfield is the study of neutral atomic hydrogen in galaxies using interferometric observations of the 21 cm emission line. My main focus is to investigate the feasibility of leveraging gravitational lensing to measure the neutral atomic hydrogen content of distant galaxies.
Contact: tariq.blecher [at] gmail.com
Location: Based at the Radio Astronomy Research Group (RARG) at the South African Radio Astronomy Observatory (SARAO) in Cape Town

Masters

Thato Manamela
Advisor(s): Prof. Roger Deane
Research interests: Visibility stacking on realistic simulations mimicking MeerKAT's observations, trying to test how this technique is more effective compared to the traditional image stacking by performing a suite of visibility stacking experiments.
Contact: thatoeugine [at] gmail.com
Location: 5-73, Natural Sciences 1, University of Pretoria

Shilpa Ranchod
Advisor(s): Prof. Roger Deane
Research interests: Aiming to detect neutral hydrogen (HI) emission of very distant galaxies that have been gravitationally lensed. I am searching for lensed HI in galaxy clusters, observed with MeerKAT-64
Contact: shilparanchod [at] gmail.com
Location: -

Micaela Menegaldo
Advisor(s): Prof. Roger Deane, Prof. Heino Falcke (Radboud University) and Jordy Davelaar (Radboud University)
Research interests: Investigating the use of unsupervised learning algorithms, specifically self organising maps, in parameter analysis of GRMHD (general relativistic magneto hydro dynamic) simulations of black holes shadows. Currently focused on the supermassive black hole located in the centre of M87
Contact: micaelamenegaldo [at] gmail.com
Location: Radboud University

Nkululeko Qwabe
Other affiliations: Hartebeeshoek Radio Astronomy Observatory (HartRAO) / SARAO
Advisor(s): Prof Roger Deane and Dr Jack Radcliffe
Research interests: I am working on developing a suite of simulations of the tied-array and interferometric performance of MeerKAT sub-arrays in order to systematically explore the scientific, technical, and processing trade-offs of MeerKAT sub-array and commensal observations, which is aimed at maximising the scientific utility of both MeerKAT and the VLBI networks it will participate in.
Contact: nkululekoqwb [at] gmail.com
Location: 5-70 Natural Sciences 1, University of Pretoria (Fridays)
Webpage: linkedin.com/in/nkululeko-qwabe-9819362a

Karina Santana
Advisor(s): Prof Roger Deane
Research interests: HI distributions of nearby galaxy mergers
Teaching: Tutor and practical demonstrator for first year students in PHY 114 and PHY 124
Contact: u16283865 [at] tuks.co.za
Location: 5-65 Natural Sciences 1, University of Pretoria

Leon Mtshweni
Advisor(s): Prof Roger Deane and Dr Kshitij Thorat
Research interests: MeerKAT observations of M87's radio halo and data calibration techniques involving machine learning.
Teaching: Tutor and practical demonstrator for PHY 114, 124, 131 and 255
Contact: u13371062 [at] tuks.co.za
Location: 5-65, Natural Sciences 1, University of Pretoria

Issac Magolego
Advisor(s): Dr Kshitij Thorat and Prof Roger Deane
Research interests: Large-scale environments of the prototypical binary AGN systems. Currently, I am conducting spectral index studies of the X-shaped radio galaxies
Contact: isaacike07 [at] gmail.com
Location: 5-73, Natural Sciences 1, University of Pretoria

Stefro Millard
Advisor(s): Prof Roger Deane and Dr Jack Radcliffe
Research interests: Binary supermassive blackholes and imaging techniques
Contact: stefromillard [at] gmail.com / u16048327 [at] tuks.co.za
Location: 5-73, Natural Sciences 1, University of Pretoria

Heinrich van Deventer
Advisor(s): Prof Roger Deane and Dr Iniyan Natarajan
Research interests: Bayesian parameter estimation for the Event Horizon Telescope, machine learning, and computational physics.
Teaching: Teaching assistant for PHY 114, 124, 263, 210 and 300
Contact: hpdeventer [at] gmail.com
Location: 5-73, Natural Sciences 1, University of Pretoria

Jacques Smulders
Advisor(s): Prof Roger Deane and Dr Chris Cleghorn (CIRG)
Research interests: Applications of machine learning and optimisation in computational astronomy
Contact: jacqsmulders [at] gmail.com
Location: 5-73, Natural Sciences 1, University of Pretoria

Fernando Ventura
Advisor(s): Prof Roger Deane and Dr Kshitij Thorat
Research interests: Finding and studying exotic radio galaxy morphologies with an interest in using machine learning to locate these unusual sources
Contact: u16000936 [at] tuks.co.za
Location: 5-73, Natural Sciences 1, University of Pretoria

Paul Wilsenach
Advisor(s): Prof Roger Deane and Dr Jack Radcliffe
Research interests: TBA
Contact: wilsenach11 [at] gmail.com
Location: 5-73, Natural Sciences 1, University of Pretoria

Honours

William Rasakanya
Advisor(s): Prof Roger Deane and Dr Kshitj Thorat
Research interests: Deep MeerKAT observation of an "X-shaped" source with a pair of black holes, galaxy NGC 326, and analysis of its jet morphology
Teaching: Tutor for PHY 114 and PHY 124 Contact: w.rasakanya [a] gmail.com
Location: 5-65, Natural Sciences 1, University of Pretoria

Graham Lawrie
Advisor(s): Prof Roger Deane
Research interests: HI detections in Galaxy clusters
Contact: u17030394 [at] tuks.co.za.
Location: 5-65, Natural Sciences 1, University of Pretoria

Past Students

Publications

2020

A Multiwavelength Analysis of the Faint Radio Sky (COSMOS-XS): the Nature of the Ultra-faint Radio Population
Algera, H. S. B., van der Vlugt, D., Hodge, J. A. et al. (including Radcliffe, J.) 2020, ApJ, 903, 2, 139 (link)

MeerKAT's discovery of a radio relic in the bimodal merging cluster A2384
Parekh, V., Thorat, K., Kale, R. et al. 2020, MNRAS, 499, 1, 404 (link)

Monitoring the Morphology of M87* in 2009-2017 with the Event Horizon Telescope
Wielgus, Maciek, Akiyama, Kazunori, Blackburn, Lindy et al. (including Deane, R. and Natarajan, I.) 2020, ApJ, 901, 1, 67 (link)

MeerKAT-16 HI observation of the dIrr galaxy WLM
Ianjamasimanana, R., Namumba, B., Ramaila, A. J. T. et al.(including Thorat, K.) 2020, MNRAS, 497, 4, 4795 (link)

GASP XXVI. HI Gas in Jellyfish Galaxies: The case of JO201 and JO206
Ramatsoku, M., Serra, P., Poggianti, B. M. et al. (including Thorat, K.) 2020, A&A 640, A22 (link)

MeerKATHI - an end-to-end data reduction pipeline for MeerKAT and other radio telescopes
Józsa, G. I. G., White, S. V., Thorat, K. et al. 2020, ADASS XXIX to appear in ASPC (link)

A probabilistic approach to phase calibration – I. Effects of source structure on fringe-fitting
Natarajan, I., Deane, R., van Bemmel, I. et al. 2020, MNRAS, 496, 801-813 (link)

The e-MERLIN Galaxy Evolution Survey (e-MERGE): Overview and Survey Description
Muxlow, T. W. B., Thomson, A. P., Radcliffe, J. F. et al. 2020, MNRAS, 495, 1, 1188 (link)

Hydrodynamical Backflow in X-shaped Radio Galaxy PKS 2014-55
Cotton, W. D., Thorat, K., Condon, J. J. et al. (including Deane, R.) 2020, MNRAS, 495, 1, 1271 (link)

Event Horizon Telescope imaging of the archetypal blazar 3C 279 at an extreme 20 microarcsecond resolution
Kim, J-Y, Krichbaum, T. P., Broderick, A. E., et al. (including Deane, R. and Natarajan, I.) 2020, A&A 640, A69 (link)

Verification of Radiative Transfer Schemes for the EHT
Gold, R,, Broderick, A. E., Younsi, Z. et al. (including Deane, R. and Natarajan, I.) 2020, ApJ, 897, 2, 148 (link)

THEMIS: A Parameter Estimation Framework for the Event Horizon Telescope
Broderick, A. E., Gold, R., Karami, M. et al. (including Deane, R. and Natarajan, I.) 2020, ApJ, 897, 2, 139 (link)

Searching for obscured AGN in z ~ 2 submillimetre galaxies
Chen, H., Garrett, M. A., Chi, S. (including Radcliffe, J.) 2020, A&A, 638, A113 (link)

High-Resolution Radio Observations of Five Optically Selected Type 2 Quasars
Krezinger, M., Frey, S., Paragi, Z., and Deane, R. 2020, Symmetry, 12, 4, 527 (link)

SYMBA: An end-to-end VLBI synthetic data generation pipeline. Simulating Event Horizon Telescope observations of M 87
Roelofs, F., Janssen, M., Natarajan, I. et al. (including Deane, R.) 2020, A&A, 636, A5 (link)

Collimated synchrotron threads linking the radio lobes of ESO 137-006
Ramatsoku, M., Murgia, M., Vacca, V. et al. (including Thorat, K.) 2020, A&A, 636, L1 (link)

2019

An insight into the extragalactic transient and variable microJy radio sky across multiple decades
Radcliffe, Jack F., Beswick, Robert J., Thomson, A. P. et al. 2019, MNRAS, 490, 3, 4024 (link)

First M87 Event Horizon Telescope Results and the Role of ALMA
Event Horizon Telescope Collaboration, Goddi, C., Crew, G., Impellizzeri, V., et al. (including Deane, R. and Natarajan, I.) 2019, The Messenger, 177, 25 (link)

Studying Black Holes on Horizon Scales with VLBI Ground Arrays
Doeleman, Sheperd, Blackburn, Lindy, Doeleman, Sheperd et al. (including Deane, R.) 2019, Bulletin of the American Astronomical Society, 51, 7, 256 (link)

The Event Horizon General Relativistic Magnetohydrodynamic Code Comparison Project
Porth, Oliver, Chatterjee, Koushik, Narayan, Ramesh et al. (including Deane, R. and Natarajan, I.) 2019, ApJS, 243, 2, 26 (link)

First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole
Event Horizon Telescope Collaboration, Akiyama, Kazunori, Alberdi, Antxon et al. (including Deane, R. and Natarajan, I.) 2019, ApJ, 875, 1, L1 (link)

First M87 Event Horizon Telescope Results. II. Array and Instrumentation
Event Horizon Telescope Collaboration, Akiyama, Kazunori, Alberdi, Antxon et al. (including Deane, R. and Natarajan, I.) 2019, ApJ, 875, 1, L2 (link)

First M87 Event Horizon Telescope Results. III. Data Processing and Calibration
Event Horizon Telescope Collaboration, Akiyama, Kazunori, Alberdi, Antxon et al. (including Deane, R. and Natarajan, I.) 2019, ApJ, 875, 1, L3 (link)

First M87 Event Horizon Telescope Results. IV. Imaging the Central Supermassive Black Hole
Event Horizon Telescope Collaboration, Akiyama, Kazunori, Alberdi, Antxon et al. (including Deane, R. and Natarajan, I.) 2019, ApJ, 875, 1, L4 (link)

First M87 Event Horizon Telescope Results. V. Physical Origin of the Asymmetric Ring
Event Horizon Telescope Collaboration, Akiyama, Kazunori, Alberdi, Antxon et al. (including Deane, R. and Natarajan, I.) 2019, ApJ, 875, 1, L5 (link)

First M87 Event Horizon Telescope Results. VI. The Shadow and Mass of the Central Black Hole
Event Horizon Telescope Collaboration, Akiyama, Kazunori, Alberdi, Antxon et al. (including Deane, R. and Natarajan, I.) 2019, ApJ, 875, 1, L6 (link)

Towards the first detection of strongly lensed H I emission
Blecher, Tariq, Deane, Roger, Heywood, Ian et al. 2019, MNRAS, 484, 3, 3681 (link)

The synergy between VLBI and Gaia astrometry
van Langevelde, H., Quiroga-Nuñez, L. H., Vlemmings, W., et al. (including Natarajan, I. and Deane, R.) 2019, Proceedings of the 14th European VLBI Network Symposium (link)

Exploring Sub-Array Strategies for MeerKAT-VLBI
Qwabe, N. and Deane, R.; 2019, Proceedings of the 14th European VLBI Network Symposium (link)

Initial progress toward planar integrate, low-cost water vapour radiometers
Stander, T., Cerfonteyn, W., Deane, R. et al. 2019, Proc. SPIE 11043, Fifth Conference on Sensors, MEMS, and Electro-Optic Systems, (link)

Last updated - 03/12/2020

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