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Sarah White – The G4Jy sample of AGN

Apr 22 @ 11:00 am - 12:00 pm

Thursday 22 April 2021

Sarah White (SARAO, Rhodes)

The G4Jy sample of AGN

Powerful active galactic nuclei (AGN) 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 ~2,000 of the brightest radio-sources in the southern sky (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). This instrument is the precursor telescope for the low-frequency component of the Square Kilometre Array (SKA), and allows us to select radio galaxies in an orientation-independent way (i.e. minimising the bias caused by Doppler boosting, inherent in high-frequency surveys). Being brighter than 4 Jy at 151 MHz, we refer to these objects as the GLEAM 4-Jy (G4Jy) Sample (White et al., 2020a, 2020b). Following repeated visual inspection (using multi-wavelength information) and thorough checks against the literature, the G4Jy catalogue and overlays are publicly available (see https://github.com/svw26/G4Jy) and currently provide mid-infrared identifications for 86% of the sources. 140 G4Jy sources have been observed using Open Time on MeerKAT (Sejake et al., in prep.), and I will also describe follow-up using ATCA, the VLA, and SALT. With over 10 times as many sources as the best-studied, low-frequency radio-source sample that is optically complete (the revised Third Cambridge Catalogue of Radio Sources; 3CRR), the G4Jy Sample will allow models of powerful AGN to be tested more robustly. https://list.saao.ac.za/wws/subscribe/saaotalks


Apr 22
11:00 am - 12:00 pm
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