Data reanalysis places new constraints on powerful extragalactic technical signatures

Credit: University of Manchester

At the 2022 International Astronautical Congress in Paris, France, the University of Manchester and Breakthrough Listen (the initiative to find signs of intelligent life in the universe) announced a reanalysis of existing data that expands the search for extraterrestrial intelligence (SETI) to a new world. The parameter space scientist is setting strict limits on the existence of extragalactic technical fingerprints.

Realizing that radio polls target nearby stars Also sensitive to background cosmic objects, in particular galaxies, galaxy clusters and galaxy clusters, Professor Michael Jarrett of the University of Manchester, in collaboration with Berkeley SETI Standard Institute Director Dr. in galaxies and other cosmic bodies outside our Milky Way.

They focused on previous observations made by the Green Bank Telescope (GBT) looking at 469 target fields called Breakthrough Listen, which were far from the mysterious gas and dust in the plane of our Milky Way galaxy. In these fields, they have identified more than 140,000 extragalactic systems, including many astrophysical oddities: interacting galaxies, various types of active galactic nuclei, radio galaxies, and several gravitational lensing systems.

Most of these sources are located at cosmic distances, but the inventory also includes many nearby galaxies, groups of galaxies, and galaxy clusters. Although these systems are located many millions of light years Far away, if the strength of the technical signatures follows an approximate power-law distribution (as transmitters do here on Earth), there may be a few rare but very bright signals detectable.

“Breakthrough Listen is also targeting 100 nearby galaxies, but in the future we will specifically monitor large concentrations of stars at cosmic distances to further search for very bright and very rare technological fingerprints,” says Dr. Andrew Simeon.

Neighboring galaxies, galaxy clusters, and galaxy clusters A great place to look for these rare strong signals, these systems contain hundreds of billions of stars and many of them will host habitable planets. Because the original Breakthrough Listen surveys did not detect any technical fingerprints, Garrett & Siemion were able to place limits on the luminosity function of potential extraterrestrial transmitters, and limits on the propagation of very powerful transmitters associated with the billions of stars that make up these systems have been identified.

For a time, Garrett was upset that previous SETI surveys had not taken into account the fact that the radio telescope’s field of view also includes many distant background objects, as well as a nearby target star – he believes “SETI radio surveys place stronger constraints on the propagation of extraterrestrial intelligence in the distant universe more than we value so much.”

The paper, “Restrictions on Extragalactic Transmitters via Breakthrough Listen Observations from Background Sources” has been accepted for publication in Monthly notifications of the Royal Astronomical Society.


The breakthrough narrows the intelligent search for life in the Milky Way


more information:
Limitations on extragalactic transmitters by Breakthrough Listen observations from background sources: seti.berkeley.edu/extragalactic/

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