Fast radio bursts (FRBs) are brief, intense radio emissions of mysterious origin. The precise localization of FRB 20240304B by the MeerKAT radio telescope has enabled the identification of its host galaxy.
Observations with the James Webb Space Telescope revealed a small, star-forming dwarf galaxy with a redshift of 2.148, corresponding to a lookback time of over 10.7 billion years. Its stellar mass is about a thousand times lower than typically observed for FRB host galaxies.
This discovery sheds light on the origin of FRBs. The characteristics of this host galaxy – low mass, young age, and active star formation – support the hypothesis of a mechanism linked to highly magnetized neutron stars, known as 'magnetars', rather than the merger of two neutron stars.
The FRB signal also serves as a probe of the matter present between its source galaxy and Earth. Its journey through the Universe has highlighted the signature of two previously unknown cosmic structures: an unknown galaxy group and the nearby Virgo Cluster. FRBs could thus become valuable tools for mapping the diffuse, invisible matter composing the 'cosmic web'.
Part of the data analysis for this study was conducted at the Nançay Data Centre, an infrastructure hosted by the Nançay Radio Astronomy Observatory in partnership with the Paris Observatory - PSL, the University of Orléans, OSUC, and the CNRS.
