Updated

Updated · ScienceAlert · Oct 12

Astronomers Trace Most Distant FRB to 1,000-Times-Smaller Dwarf Galaxy 3 Billion Years After Big Bang

Updated

Updated · ScienceAlert · Oct 12

Astronomers Trace Most Distant FRB to 1,000-Times-Smaller Dwarf Galaxy 3 Billion Years After Big Bang

Q: What hidden cosmic structures did this ancient radio flash illuminate on its epic multi-billion-year journey to Earth?

It illuminated a chain of otherwise hard-to-see cosmic structures, especially a previously unknown galaxy cluster or group about 3.5 billion light-years away at redshift 0.3, and the nearby Virgo Cluster about 54 million light-years from Earth. Researchers say the burst’s signal also carried the imprint of gas in its own host dwarf galaxy and in the Milky Way. By the time FRB 20240304B reached Earth, its radio waves had been dispersed and altered by each of these environments, effectively turning the burst into a probe of matter spread across most of cosmic history. That matters because much of this ordinary matter is difficult to detect directly. Fast radio bursts act like “cosmic flashlights,” revealing ionized gas, magnetic fields and turbulence along the line of sight. In this case, the signal helped expose hidden structure in the cosmic web, including an intervening galaxy cluster that had not been identified before. So the ancient flash did more than set a distance record. It traced gas and large-scale structure from its young, star-forming host galaxy, through an unseen intervening cluster or group, across the Virgo Cluster, and into our own galaxy, giving astronomers a rare map of matter between galaxies.

3 articles · Updated · ScienceAlert · Oct 12

FRB 20240304B lasted one-thousandth of a second and traveled through about 80% of cosmic history, making it the most distant fast radio burst yet detected.
JWST identified its host as a tiny, actively star-forming dwarf galaxy at cosmic noon—about 3 billion years after the Big Bang—with 90% of its stellar mass formed in the past 30 million years.
That unusually young, metal-poor galaxy makes a magnetar a stronger candidate source than a neutron-star merger, which typically takes billions of years to occur.
The burst’s delayed low-frequency waves and millisecond smearing also let researchers probe ionized gas along its path, revealing effects from a galaxy group 3.5 billion light-years away and the Virgo Cluster.
With only about 100 FRBs tied to host galaxies so far, the Science study suggests such bursts already existed in the early universe and could become tools for mapping otherwise hidden cosmic matter.