Fast Radio Bursts (FRBs) are millisecond-duration radio signals originating from deep space. In this episode, we explore the groundbreaking discovery of FRB 20240304B, detected by the MeerKAT radio telescope in South Africa as part of the MeerTRAP survey. Subsequent near-infrared observations with the James Webb Space Telescope (JWST) pinpointed its host galaxy at an unprecedented spectroscopic redshift of z = 2.148 — tracing the signal back to just 3 billion years after the Big Bang.
Key Talking Points
- Breaking Distance Records: Prior to this discovery, the highest confirmed redshift for an FRB host galaxy was z ~ 1.016. FRB 20240304B more than doubles this distance record, allowing astronomers to probe ionized gas across roughly 80% of cosmic history.
- The Host Galaxy Profile: Deep imaging and spectroscopy from JWST revealed that the host is a low-mass, actively star-forming, metal-poor dwarf galaxy dominated by a young stellar population.
- Clues to the FRB Engine: The host's intense star formation and low metallicity support a young magnetar (a highly magnetized neutron star) as the burst progenitor, making long-delay origin models like neutron star mergers far less likely.
- Intergalactic Obstacles & Hidden Bursts: The signal shows significant pulse scatter broadening and dispersion acquired while passing through foreground plasma (including the Virgo Cluster). This high degree of scattering suggests that many distant FRBs are currently missed by existing radio surveys.
### Article Reference
Caleb, M., Nanayakkara, T., Stappers, B. W., Pastor-Marazuela, I., Khrykin, I. S., Glazebrook, K., Tejos, N., Prochaska, J. X., Rajwade, K., Mas-Ribas, L., Driessen, L. N., Fong, W., Gordon, A. C., Hoffmann, J. L., James, C. W., Jankowski, F., Kahinga, L., Kramer, M., Simha, S., Barr, E. D., Bezuidenhout, M. C., Deng, X., Lin, Z., Marnoch, L., Martin, C. D., Nugent, A., Shaji, K., & Tian, J. (2026). A fast radio burst at redshift 2, three billion years after the Big Bang. Science, DOI: [10.1126/science.adz2675](https://doi.org/10.1126/science.adz2675).
Acknowledements: Podcast prepared with Google/Gemini Notebook. Illustration credits: NASA, ESA, CSA, STScI, Themiya Nanayakkara (USYD); Image Processing: Joseph DePasquale (STScI)