Fast radio bursts (FRBs) are millisecond-duration pulses of radio emission originating from extragalactic sources. An international team of astronomers has now detected a new FRB and localized its source to a group of two or three merging galaxies at a redshift of about 1, more than halfway back (about 8 billion years ago) to the Big Bang. Labeled FRB 20220610A, the burst is unusually bright, challenging models of the FRB emission mechanism.
FRBs are brief pulses of radio emission originating from distant extragalactic sources.
Although the astrophysical processes that cause FRBs aren’t fully understood, the signals they produce can be used to infer information about the cosmic environments they pass through as they travel across the Universe, including the nature of their galaxies of origin and the distribution of plasma in the intergalactic medium.
Previous studies have shown that FRBs localized to host galaxies at different redshift exhibit a positive correlation between the extragalactic dispersion measure, the density of electrons the radio signal passed through as it traversed the intergalactic medium, and the host redshift — a measure known as the Macquart relation.
However, this relation has only been measured using identified FRB host galaxies at nearby redshifts.
FRB 20220610A was discovered in June 2022 by the ASKAP radio telescope in Australia.
“Using ASKAP’s array of dishes, we were able to determine precisely where the burst came from,” said Dr. Stuart Ryder, an astronomer from Macquarie University.
“Then we used ESO’s Very Large Telescope (VLT) to search for the source galaxy, finding it to be older and further away than any other FRB source found to date and likely within a small group of merging galaxies.”
The discovery confirms that FRBs can be used to measure the ‘missing’ matter between galaxies, providing a new way to ‘weigh’ the Universe.
Current methods of estimating the mass of the Universe are giving…
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