The power of combining the radio and far infrared to study galaxy evolution

This thesis focuses on how the combination of far infrared (FIR) and radio emission can be used to better understand galaxy evolution. Radio and FIR emission is linked to star formation, which plays a major role in the evolution of galaxies. I have combined FIR observations from Herschel and radio observation from the LOFAR radio telescope in order to take advantage of this. Chapter 2 details the construction of a joint FIR-radio catalogue, using the likelihood ratio method, to link the radio catalogue to a multiwavelength optical/NIR catalogue. Subsequently the FIR fluxes were measured by deblending the FIR maps using the radio galaxies as positional priors. This method creates a perfect sample for measuring the far infrared radio correlation (FIRC). Chapter 3 focuses on the measurement of the FIRC at 150MHz with a mass complete sample. I find that the FIRC is primarily dependent on the stellar mass of the host galaxy with a minor dependence on the redshift. Finally, chapter 4 describes how I used XID+ to measure the flux posterior for galaxies at 150MHz that were undetected in the LOFAR radio catalogues. I found that XID+ is able to accurately measure the flux of point like radio galaxies. These results were used to remeasure the FIRC and evaluate the best approach for extending XID+ to work on radio maps.