APEC Seminar (Astronomy - Particle Physics - Experimental Physics - Cosmology)

Speaker: Jacinta Delhaize (University of Cape Town)
Title: The MIGHTEEst radio galaxies
Date (JST): Thu, Feb 16, 2023, 16:00 - 17:00
Place: Zoom
Abstract: The perceived scarcity of giant radio galaxies (GRGs) is now being challenged thanks to the huge improvements in surface brightness sensitivity provided by SKA precursors and pathfinders. Understanding more about these systems will inevitably lead to a better understanding of radio-mode feedback, as well as the duty cycle of these enormous AGN. I will present a new study of several giant radio galaxies in the MeerKAT International GigaHertz Tiered Extragalactic Exploration (MIGHTEE) survey. The MeerKAT telescope provides exquisite sensitivity to the diffuse emission of the large-scale jets and lobes of GRGs. MIGHTEE L-band observations have therefore unveiled a number of GRGs across the target fields which were hitherto undetected, even by sensitive surveys with the VLA. We have performed a spatially-resolved spectral index study of the MIGHTEE GRGs, by comparing the L-band data with lower frequencies, including new MeerKAT UHF band observations of COSMOS. The good resolution of MeerKAT at both L and UHF bands allows us to examine spatially-resolved spectral ages across the GRGs. Our goal is to better understand these enigmatic systems, and to determine whether age is a primary driver of their huge sizes.