30 MARZO 2021 ore 15:00

New high-frequency radio observations of the Cygnus Loop SNR

Dr. Sara Loru (INAF-OACt, Italia)
New high-frequency radio observations of the Cygnus Loop SNR

Abstract: Supernova remnants (SNRs) result from the stellar mass ejected during a supernova explosion, and their spatial and  temporal evolution is strongly related to the interaction between the SNR shocks and the surrounding interstellar medium (ISM).
Thanks to its large size, its location well out of the Galactic plane, and its high brightness, the middle-age SNR Cygnus Loop  is well suited for observations across the entire electromagnetic spectrum. In the radio band, this SNR presents a very characteristic  morphology with a large northern circular shell and a bubble-like shell located in the southern part.
The radio studies showed substantial differences between these two regions, which could be related to the local magnetic field conditions, particle populations with different energy distribution or peculiar emission mechanisms. Despite this scientific interest, sensitive flux density measurements are missing at higher frequencies (above ∼ 5 GHz), due to the technical difficulties in performing radio continuum observations of such a large source.  These arguments made Cygnus Loop a very interesting target to observe with the Italian radio telescopes.
I will present the work based on single-dish observations of the large and complex Cygnus Loop SNR from 7.0 to 24.8 GHz with the Medicina and the Sardinia Radio Telescope. These observations allowed us to investigate the radio spectrum of Cygnus Loop in a yet unexplored frequency range, and to study the energetics of the accelerated particles and the possible emission mechanism that takes place in this SNR.
These results highlight that SNRs are an interesting challenge for new generation radio telescopes and powerful laboratories to study  theoretical aspects of Cosmic-Ray acceleration processes.


Breve CV della Dr. Sara Loru:

ha conseguito la laurea magistrale presso l'Università degli Studi di Cagliari con una tesi dedicata alle prime osservazioni in banda C di sorgenti estese quali i SNRs con SRT nell'ambito della sua fase di validazione scientifica. Nel 2019 ha conseguito il Dottorato di Ricerca presso l'Università di Cagliari ed in collaborazione con l'INAF-Osservatorio Astronomico di Cagliari con un progetto dedicato allo studio e alla caratterizzazione spettrale di SNRs tramite osservazioni radio single-dish. Dal 2019 svolge l'attività di PostDoc presso l'INAF-Osservatorio Astrofisico di Catania con un assegno di ricerca dedicato allo studio dei SNRs galattici osservati con precursori e pathfinders di SKA.