School of Chemistry & Physics

Large-Scale Structure of the Universe Focus of PhD Research

In 2017, when Ayodeji Ibitoye watched a newsclip celebrating the efforts of UKZN Professor Yin-Zhe Ma to solve the “missing baryons” problem, he decided that this was the supervisor he wanted for his PhD. And so began his association with UKZN ….

Now Ibitoye has graduated with a PhD degree in Physics. His study focused on the cross-correlation of the large-scale structure of the universe.

‘Dr Ayodeji Ibitoye’s thesis works on the cutting-edge observational probe of large-scale structure,’ explained Ma. ‘He used the thermal Sunyaev Zel’dovich effect to study the effect of hot-ionized gas around galaxy clusters, and galaxy density field from Infrared survey to probe the galaxy bias and the cross-correlation properties.

‘He cross-correlated thermal Sunyaev-Zel’dovich maps derived from Planck cosmic microwave background maps with the galaxy density field traced by infrared emission in WISE maps and with maps of the integrated Sachs-Wolfe effect derived from Planck cosmic microwave background maps as a second study.

‘He found the best-fitting value for the hydrostatic bias, to be broadly consistent with the literature, and found the linear galaxy bias to be the tightest to date.

‘In his project, he equally introduces a new parameter that quantifies the contamination of the cosmic infrared background to tSZ-cross correlation studies with galaxy and ISW which is a first estimate of such studies.’

Ibitoye was motivated by a desire to involve his home country, Nigeria, in astronomy research. ‘Nigeria would be a good site for a 25m deep radio spectrum deep space observation telescope for carrying out radio pulsar studies, spectroscopy and planetary research in space science,’ he said. ‘I hope to collaborate with the international community to make astronomy more intensive in Nigeria in the near future.

‘I embarked upon a PhD to gain sufficient knowledge to be able to communicate intelligently with my colleagues in the rest of the world who are astrophysicists, that GOD indeed exists,’ added Ibitoye, who recently released a book – 7 Astronomical and Cosmological Wonders in the Bible – in an attempt ‘to find the balance between Science and the God of Science.’

Ibitoye’s research has made a number of contributions: ‘The estimate I achieved in my work for the bias-parameter amongst other cosmological parameters helps to release the tension between CMB-based and cluster-based constraints of cosmological parameters,’ he said.

Ibitoye is currently working with Ma, exploring data from the MeerKAT telescope.

He gave thanks first and foremost to God for his sound health and ‘the Grace he gave me to finish this degree’; as well as to his supervisor, ‘who believed in me and gave me the space to fly’; and to postdoctoral fellows Drs Denis Tramonte and Wei-Ming Dai.

‘I would also like to appreciate my darling and precious wife Mrs Yimika-Ayo Ibitoye who graduated from the College of Health Sciences with an MSc in Medical Science summa cum laude. From her I learned that the success secured in marriage guarantees 78% success in other areas of life.

‘Lastly, I appreciate my wonderful parents Mr and Mrs Ibitoye and siblings Mrs Banke Oladipo née Ibitoye, Akinlolu Ibitoye and Seyi Ibitoye for believing in me; and all the other members of my research team.

‘I would like to encourage my other colleagues who are still students that the academic journey is not a frictionless path, but your resilience and doggedness are major lubricants,’ said Ibitoye.

Words: Sally Frost

Photograph: Supplied