New searches for high-redshift radio galaxies using the MWA GLEAM survey

High-redshift radio galaxies (HzRGs; e.g. review by Miley & De Breuck 2008) are vital probes of massive galaxy formation and evolution. Low-radio-frequency-selected samples have considerable potential in finding more of these rare objects (e.g. the recent discovery of the most distant radio galaxy known at z=5.72; Saxena et al. 2018). Drouart et al. (in prep.) have developed a novel selection technique for efficiently finding HzRGs, making use of spectral curvature at low radio frequencies, along with a standard cut in near-infrared K-band magnitude. This approach has already resulted in the discovery of the second-most distant radio galaxy known, at z=5.55. In this talk, I will present initial results from an ongoing project to extend the Drouart et al. study over much wider areas, and to radio flux density levels an order of magnitude fainter. In particular, we make use of an updated catalogue from the Galactic and Extragalactic All-sky Murchison Widefield Array survey (MWA GLEAM Year 1 + Year 2; Franzen et al. in prep.), as well as near-infrared K-band data from the ESO VISTA Kilo-degree Infrared Galaxy survey (VIKING; Edge et al. 2013). I will describe efforts to refine the selection process using both the above described data, as well as additional multi-wavelength data sets. I will also discuss the prospects of further opening up new parameter space by finding more HzRGs with radio luminosities similar to, and fainter than, the Saxena et al. (2018) discovery. Identifying radio galaxies above z > 6 (i.e. during the Epoch of Reionisation) would enable many exciting scientific opportunities, and I will conclude with some thoughts on this topic