The interplay between environment and galaxy evolution for radio detected galaxies with state-of-the-art radio and multi-wavelength surveys

Extragalactic radio surveys provide a unique insight into the Universe, observing both active galactic nuclei (AGN) and star forming galaxies (SFGs) over relatively large areas and out to large distances in the Universe without any attenuation by dust which can plague other wavelengths. Therefore, radio surveys provide a unique window on the Universe and trace populations where we know the feedback from these sources (AGN or star formation) is crucial in shaping the evolution of galaxies.

As such, they are important probes in observational cosmology. However, radio surveys are limited in their lack of redshift information alone and so radio sources must be studied using the wealth of information which can be gained across the electromagnetic spectrum in order to maximise the information we can gain from these studies.

Current radio surveys with SKAO precursors (e.g. with LOFAR and MeerKAT) are producing vast data sets of radio sources which go deeper over significant areas than ever before. This provides increased statistics than previously possible at these depths and to study faint populations to study the clustering. It also allows use of a number of techniques (Halo Occupation Distribution Modelling) to be used to greater accuracy then previously possible in radio clustering as well as employing recently developed techniques (k- Nearest Neighbour clustering) on radio continuum samples.

In this project, the student aims to extend our understanding of the galaxy-halo connection observed for radio detected sources through using statistical clustering-based techniques to study the clustering of different source populations in modern radio surveys, combining with deep multi-wavelength data, including deep spectroscopic data. The student will work within a group which is leading studies of the radio galaxy-halo connection (e.g.

Hale+ 2018, Hale+ 2024) and with a wealth of involvement in the key surveys and instruments which will be important for this work (Jarvis+ 2016, Hale+ accepted). They will work within a team of postdoc and students who have key expertise in the field, work on complimentary science goals and the student will work with complementary expertise as well as in a number of large, international collaborations.

Initial work of the student will include studying whether the clustering of radio AGN compared to matched samples of galaxies selected at other wavelengths can help inform whether radio selected AGN preferentially reside in different haloes to ordinary galaxies. This could have potential implications for understanding if AGN form in certain environments and, if so, understanding why this may be the case.

This also may have potential implications for understanding whether the feedback mechanism imposed in cosmological simulations need to account for other factors when injecting AGN feedback (and different types of feedback in the simulations). After this, the student will continue to work on the topic of observational cosmology using radio-selected galaxy with state-of-the-art radio and multi-wavelength data, developing our understanding of the properties of dark matter haloes which are suitable in hosting radio galaxy populations across cosmic time.

Their research can take a number of avenues as the student develops over their PhD taking into account their interests developed as they progress and adapting to account for new ideas, new techniques and data availability to push forward knowledge of how radio galaxies evolve within the context of the larger cosmic web over time.