The Nature of Polarized Sources in the MIGHTEE XMM-LSS Deep Field
2026-05-20 11:30 - 12:30 UTC | Sede A. Riccò, Via Santa Sofia 78, Catania
Recording: NOT AVAILABLE
DATE: Wednesday, May 20, 11:30 a.m.
ORGANIZER: INAF-OACT
LOCATION: AULA OVEST (INAF-OACT) + remote
Link for the remote audience:https://meet.google.com/wvf-uwxo-oyj
SPEAKER: Lennart Heino (INAF)
ABSTRACT:This study explores the polarized emission of the faint extragalactic radio sources in the MIGHTEE (MeerKAT International Giga-Hertz Tiered Extragalactic Exploration, Jarvis et al., 2016) survey in order to systematically study cosmic magnetic fields in galaxies to high redshift. Reaching a sensitivity of 1.5 µJy/beam at a resolution of 5 arcseconds, MIGHTEE is providing an opportunity to chart the evolution of polarized emission from distant galaxies over cosmic time.
The MIGHTEE survey detects polarized emission for a large number of radio sources down to total intensity flux densities of the order of 100 µJy. At these flux densities the source population is increasingly dominated by star-forming galaxies (SFGs) as opposed to active galactic nuclei (AGNs). While polarized emission of AGN can be traced to very distant galaxies, polarized emission of SFGs at moderate distance has been detected only once.
I use multi-wavelength criteria to classify MIGHTEE radio objects as either SFG or AGN. I perform Rotation Measure Synthesis (RMSY) on the spectro-polarimetric data cubes and use the polarization and RMSY spectra to search for polarized emission. A comparative analysis of the polarization properties of SFGs and AGNs is performed. The analysis is extended to the lowest possible flux densities using stacking techniques. I will show preliminary results of the MeerKAT polarization studies of radio sources down to a sensitivity at the micro-Jansky level.

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