| 10th of May 2017 |
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| ATNF Colloquium |
| The path to ASKAP: faint things and curvy things |
| by Jordan Collier (Western Sydney Uni & CASS) |
| Abstract. During my thesis, I studied two classes of AGN: Infrared-Faint Radio Sources (IFRSs) and Gigahertz-Peaked Spectrum (GPS) / Compact Steep Spectrum (CSS) sources. IFRSs are recently discovered objects, whose nature was unconfirmed. We found a population of >1300 brighter IFRSs and measured the first spectroscopic redshifts, which showed they were high-z radio galaxies at z > 2 that might extend out to z ~ 7 and significantly increase the number of known high-redshift galaxies. We observed the faintest population of GPS/CSS sources to date, consisting of ~140 sources, using high-resolution ATCA observations. We observed the most compact of these with the LBA, determined their linear sizes and used many radio observations spanning 70 MHz - 34 GHz to model their radio spectra and spectral ages. We find evidence that low-luminosity GPS/CSS sources are similar to brighter samples, which are young and evolving GPS and CSS sources that may experience frustration and intermittent activity. This study of young and distant radio sources led to working on the scientific validation of ASKAP continuum data, an important step both for commissioning the instrument and assessing its performance, and for beginning to develop the framework for the automated quality control and scientific verification that will be necessary for EMU. I will discuss the automated pipeline I have developed to produce a science validation report of ASKAP continuum data, the current results and the next steps. |