From distant gamma rays to spinning pairs of stars

From distant gamma rays to spinning pairs of stars: “A Transient IDIA”

The MeerKAT radio telescope array combines a number of unique features; it has an excellent instantaneous sensitivity, a superb image quality for snapshot imaging, and, from its inception, the science programs on MeerKAT agreed on a shared data policy, whereby each data set from the eight MeerKAT Large Survey Projects (MLSPs) can be used by multiple groups for different science goals. 

This use of the MeerKAT data opens up the potential to discover a wide range of new and unusual astrophysical objects known as transients; fast evolving astronomical phenomena whose variation can be measured on the timescale of observations. Exploring this discovery space with MeerKAT and with the associated MeerLICHT telescope lies at the heart of ‘A Transient IDIA’, where various data science aspects are combined: real-time source classification, machine learning, and data fusion of complex  data bases.

MeerLICHT was inaugurated on 25 May 2018 and is designed to take observations in conjunction with MeerKAT and the Southern African Large Telescope. The innovative concept of MeerLICHT is that it will be permanently coupled to the MeerKAT observing schedule for the lifetime of the MLSPs.

“A Transient IDIA” serves as a pathfinder for SKA science in terms of commensal exploration of data products on cloud infrastructure.

The project builds on the core objectives of the MeerKAT Large Survey Project ThunderKAT. It aims to combine the radio MeerKAT data stream with that of the optical MeerLICHT telescope. MeerLICHT data is streamed directly from Sutherland to IDIA into a real-time pipeline. Already, MeerLICHT pipeline has been completed by UCT PhD student Kerry Paterson and ThunderKAT data analysis of MeerKAT data has begun on the IDIA cloud infrastructure.

In her PhD thesis (completed in 2019), Dr. Paterson presents results from the MeerLICHT pipeline obtained during the commissioning phase of the telescope. She is now a postdoctoral fellow at Northwestern University (Chicago, USA) and the MeerLICHT pipeline is fully operational.

A part of “A Transient IDIA” is the analysis of all the ThunderKAT data. It includes weekly monitoring of 4-5 astronomical objects called X-ray binaries; black holes or neutron stars spinning around one another, a sample of 10 Cataclysmic Variables; pairs of stars spinning around one another and sharing material, and a unique Gamma Ray Burst; an event, in this case associated with the formation of a black hole in a distant galaxy.

In all of these observations, South African students and postdoctoral researchers members of the ThunderKAT team are involved in the analysis of data on the IDIA cloud, including Itumeleng Monageng (X-ray binaries), Dante Hewitt (Cataclysmic Variables) and Reikantseone Diretse (Gamma Ray Burst).