Radio galaxies near the epoch of reionisation

Saxena, A. (2019)

Doctoral Thesis

This thesis explores the theoretical and observational properties of distant massive galaxies that harbour active black holes in their centres and shine brightly at radio wavelengths. These radio galaxies are some of the rarest objects in the Universe, and studying them reveals more about the formation and evolution of massive galaxies and black holes in the Universe. In Chapter 2, we model faint radio galaxies at record distances (high redshifts) using a simple model to characterise the overall evolution of radio galaxies. We find that our model replicates well the properties of radio galaxies that are nearer to us. This gives us confidence in the predictions at higher redshifts (larger distances), where data is scarce. In Chapter 3, we compile a list of promising distant radio galaxies using all-sky radio datasets. We present observations for these candidates at a high resolution. In Chapter 4, we report the discovery of the most distant radio galaxy observed till date, TGSS J1530+1049. The galaxy’s distance is confirmed using data from various telescopes. In Chapter 5, we present a detailed study of other distant radio galaxies from our initial sample, showing their properties to be different from brighter radio galaxies.

• Galaxies
• High redshift
• Radio astronomy
• Early universe
• Epoch of reionisation

• All authors: Saxena, A.
• Supervisor: Röttgering, H.
• Co-supervisor: Duncan, K.
• Committee: Franx, M.; Werf, P. van der; Miley, G.; Jackson, C.; Pentericci, L.; Bouwens, R.; Hodge, J.; Breuck, C. de
• Qualification: Doctor (dr.)
• Awarding Institution: Sterrewacht, Science, Leiden
• Date: 2019-06-26
• ISBN (print): 9789463803793