https://phys.org/news/2025-01-fast-radio-astronomers-believed-knew.html
created by a_pusy on 25/01/2025 at 17:26 UTC
217 upvotes, 3 top-level comments (showing 3)
Comment by Andromeda321 at 25/01/2025 at 18:40 UTC
233 upvotes, 7 direct replies
Astronomer here! Interesting result!
The burst recorded here is a Fast Radio Burst (FRB), which are bursts of radiation that come from beyond our galaxy, last just a millisecond (some repeat over time, some are one-offs), and are so luminous that they’re one of the brightest things in the radio sky for that millisecond. We don’t know what causes them, but there are many theories- one popular one for example suggests they come from very young magnetars- highly magnetized neutron stars. It’s also possible more than one thing causes FRBs- we don’t know yet!
Now, one way to know what causes an FRB is look at a bunch of their locations, and identity the type of galaxy host. Some types of events are more popular from some types of galaxies than others- supernovas (exploding stars) for example are more common in galaxies with a lot of star formation, because stars that explode live short lives. And enter this repeating FRB- the paper reports that they looked at many bursts from one FRB, and found a precise location in a galaxy 2 billion light years from us, on the outskirts of an elliptical galaxy. These types of galaxies are old, and there’s evidence that this came from a globular cluster to boot- literally a kind of cluster of stars that are the oldest we know of in our universe.
Whoa, ok! What does that tell us? Well there’s always the chance of a random stray young object there, or a low level surface galaxy you can’t see, but it’s tough to argue about a young magnetar in that kind of environment. Instead, it indicates the FRB could be created by something far older- an old star merging, or a black hole, etc. We frankly don’t know what is true- all we know is this is not strong evidence you’d expect if it’s a young magnetar.
Finally, worth noting we definitely have seen FRBs from unusual galaxies in the past, and there’s no clear pattern yet because we haven’t localized too many of them yet to a specific galaxy (it’s hard for reasons I won’t get into). So time will tell if this is actually a clue, or something random. Stay tuned!
Comment by SAUbjj at 25/01/2025 at 17:42 UTC
23 upvotes, 0 direct replies
I attended a talk by one of the lead researchers this week, it was very interesting
IIRC: Essentially, they identified this Fast Radio Burst (FRB) shown in the picture. These are thought to be from neutron stars, but it unclear. They've detected lots of these signals before, but after improving their localization algorithms, this is the first time one has been localized outside of a galaxy, and outside of a red and dead galaxy at that. They really only expect the FRBs to be in star forming galaxies, so the fact that one is *outside* of a *dead* galaxy is very surprising. The researcher said it's probably a globular cluster or a dwarf galaxy that isn't visible at these distances (z > 4)
Comment by Archduke_Of_Beer at 26/01/2025 at 09:02 UTC
3 upvotes, 1 direct replies
Is it aliens?