Low-frequency observations with SKA's precursors and pathfinders are unveiling an exciting new variety of complex radio morphologies, associated with ageing and re-accelerated plasmas injected by radiogalaxies.
It is becoming increasingly evident that we need to better model the evolution of such "fossil" electrons, in order to understand the reservoir of electrons which accretion...
The LOFAR Low Band Antenna (LBA) system makes LOFAR a case-of-study for the exploration of ultra-low frequencies (<100 MHz). Understanding how to collect, store, reduce and analyse LOFAR LBA data, is key to have a fast track towards SKA-low science.
In this talk I will give an overview of the LOFAR Sky Surveys with emphasis on the LOFAR LBA Sky Survey, describing the planning, status, data...
The LOFAR Two-meter Sky Survey (LoTSS) is an on-going survey aimed at imaging the entire northern sky at 120-168 MHz with unprecedented resolution and sensitivity in this frequency range. It had its first data release in 2019 and a new, second data release is forthcoming. LoTSS-DR2 will comprise images for 5700 square degrees of the northern sky, where more than 4 million radio sources have...
In recent years the unprecedented sensitivities provided by SKA precursors/pathfinders have started revolutionising our view even of previously well-known objects such as jetted AGN. In particular, observations in the MHz-frequency regime are able to unveil the oldest plasma injected by AGN jets in their surrounding medium, providing new insights into the jet duty-cycle and feedback, as well...
Diffuse radio emission at the center of galaxy clusters is observed with different size and properties.
Gian halos are Mpc-size sources predominantly found in massive merging clusters and are likely due to the re-acceleration of particles by turbulence injected in the intra cluster medium (ICM) during major merger. Mini halos are 100-500 kpc-size sources found in relaxed clusters with a...
Clusters of galaxies provide ideal physical laboratories for studying a wide range of physical processes associated with hot gas (thermal components) and magnetic fields (non-thermal components). However, studying cluster magnetic fields in detail is difficult, due to the wide variety of physical processes undergone by clusters during their lifetime. Diffuse radio sources (such as the...
In this talk, I will present new results from LOFAR observations of the Coma cluster. Low frequency and high sensitivity data allow us to map the emission in detail, discover new emission associated to the large-scale structure around the cluster, and constrain particle acceleration mechanisms in the halo, birdge, and relic.
Clusters of galaxies are the largest virialized systems in the Universe and thus are ideal laboratories to study the formation and evolution of cosmic structures. The baryonic matter of clusters consists of stars and galaxies, and of the intracluster medium (ICM). At the same time, radio observations have proved that the ICM is mixed with a non-thermal component, i.e. highly relativistic...
