RSAA Colloquia / Seminars / Feast-of-Facts: Thursday, 21 June 2018, 11:00-12:00; Duffield Lecture Theatre

Sarah White

"The most powerful radio-sources in the southern hemisphere"

Powerful radio-galaxies feature heavily in our understanding of galaxy evolution. However, when it comes to studying their properties as a function of redshift and/or environment, the most-detailed studies tend to be limited by small-number statistics. In this talk, I will present a new sample of nearly 2,000 of the brightest radio-sources in the southern hemisphere (Dec. < 30 deg). These were observed at low radio-frequencies as part of the GaLactic and Extragalactic All-sky MWA (GLEAM) survey, conducted using the Murchison Widefield Array (MWA). Being brighter than 4 Jy at 151 MHz, we refer to these objects as "The GLEAM 4-Jy Sample". Thanks to the location of the MWA in a protected, radio-quiet zone, we have excellent spectral coverage for these sources, with 20 radio flux-densities spanning a frequency range of 72-231 MHz. A key component of this project is identifying the appropriate host galaxy of the radio emission, with these positions feeding into target lists for the Taipan Galaxy Survey. Having 10 times as many sources as the most-prominent, low-frequency radio-source sample that is optically complete (the revised Third Cambridge Catalogue of Radio Sources; 3CRR), the GLEAM 4-Jy Sample will allow models of powerful active galactic nuclei to be tested more robustly.