Astronomers detect fast radio burst that traveled over ten billion years

Astronomers detected a fast radio burst, designated FRB 20240304B, on March 4, 2024, using the MeerKAT radio telescope in South Africa.

The burst’s radio waves traveled more than 10 billion years before reaching Earth. The burst lasted a few milliseconds. The signal showed a large dispersion measure, indicating passage through electrically charged material.

By measuring dispersion, researchers estimated the burst originated when the Universe was about 3 billion years old. The host galaxy of the burst was identified with NASA’s James Webb Space Telescope, appearing as a faint, clumpy object at a redshift of 2.148. Its stellar mass is about 10 million times the mass of the Sun. The galaxy’s metal content is roughly one‑tenth of the Sun’s abundance of elements heavier than helium.

Approximately 90% of the galaxy’s stars formed within the 30 million years preceding the burst. The burst arrived with a scattering tail lasting several thousandths of a second, likely caused by gas in the host galaxy. Part of the dispersion excess came from the signal passing about 3 million light‑years from the centre of the Virgo Cluster.

Researchers Manisha Caleb and Themiya Nanayakkara of the University of Sydney led the analysis and reported a 97.5% confidence in the galaxy‑burst association. MeerKAT serves as a precursor to the SKA Observatory telescopes now being built in South Africa and Australia. The burst’s radio wave polarization twist (Faraday rotation) encodes information about magnetic fields along its path, allowing measurement of cosmic magnetic field complexities.

The detection shows that fast radio bursts were being produced as early as around 3 billion years after the Big Bang, probing about 80% of cosmic history. The study presenting these results was published in the journal Science. The host galaxy’s young, low‑mass, metal‑poor nature supports the hypothesis that at least some fast radio bursts originate from young magnetars.

Caleb and Nanayakkara said, ‘What surprised us was just how small and low‑mass it turned out to be.’

The Hubble Space Telescope observed the Fornax Ultra Deep Field for more than 270 hours, revealing nearly 10,000 galaxies in that region. Researchers directed the James Webb Space Telescope to the same Fornax region to search for objects missed by Hubble. Faint dwarf galaxies in the Fornax cluster have low surface brightness, with a stellar density of about one star per million cubic parsecs, roughly a million times lower than near the Sun.