Publications by authors named "Emanuela Orru"
Article Synopsis
- Fast Radio Bursts (FRBs) are powerful, brief astrophysical events that have been detected at various frequencies, but lower-frequency emissions have been challenging to observe.
- One notable FRB, FRB 20180916B, shows a 16.35-day periodicity and emits at frequencies as low as 120 megahertz, with its activity window varying by frequency — narrower and earlier at higher frequencies.
- The findings indicate that lower-frequency emissions can escape their surrounding medium, suggesting that some FRBs are in environments that don't absorb low-frequency signals, contradicting previous theories about absorption affecting FRB periodicity.
Due to their steep spectra, low-frequency observations of Fanaroff-Riley type II (FR II) radio galaxies potentially provide key insights in to the morphology, energetics and spectrum of these powerful radio sources. However, limitations imposed by the previous generation of radio interferometers at metre wavelengths have meant that this region of parameter space remains largely unexplored. In this paper, the first in a series examining FR IIs at low frequencies, we use LOFAR (LOw Frequency ARray) observations between 50 and 160 MHz, along with complementary archival radio and X-ray data, to explore the properties of two FR II sources, 3C 452 and 3C 223.
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