Contributed Talk - Splinter RadioSky

Wednesday, 14 September 2022, 15:03   (SFG 1030 / virtual RadioSky)

On the pathway to the SKA: Exciting science with the deep and wide-field ASKAP survey of the GAMA23 field

Gurkan et al.
Thuringer Landessternwarte Tautenburg

Deep wide-field radio surveys in conjunction with available multi-wavelength data open a range of new exploration windows to the Universe. A 60 sq degree southern region was observed with the Australian SKA Pathfinder (ASKAP) at 888 MHz as part of the early science programme of Evolutionary Map of the Universe (EMU), reaching 35microJy/beam sensitivity and 10 arcsec resolution. The observed region has excellent legacy data sets: (i) optical spectroscopy up to z~0.4 provided by the Galaxy And Mass Assembly (GAMA) project; (ii) photometric data from optical to mid- and far-infrared; (iii) photometric redshifts reaching distances beyond the spectroscopic limit. Cataloguing and source identification processes along with visual inspection provided ~43000 radio sources detected at 5σ, of which 65% have optical counterparts. Initial investigation of the radio sources in the field has revealed new giant radio galaxies (GRGs). There are 63 GRGs with z<1.7 with sizes going up to 2.7 Mpc. Preliminary investigations show that a number of these GRGs show linearly polarised emission. The sample of GRGs allows us to not only constrain AGN evolution but also enables us to study polarization properties and the magnetic fields associated with these rare objects. As part of ongoing studies of normal and active galaxies, we utilised the depth of this radio survey and the available spectroscopic and photometric data to investigate the physical properties of radio-quiet active galaxies at much lower luminosities than any study attempted before. The results show that a link between radio emission and AGN outflows still persists even at low-luminosities. I will present the radio survey along with the initial science results, which are the first steps towards the exciting science with ASKAP in the pre-SKA era.