Astronomers have noticed an odd blast of gamma radiation from house that defies categorisation, and it could imply a spot in our understanding of how black holes kind
7 December 2022
An odd blast of radiation from house could upend how we categorise such flashes, known as gamma ray bursts (GRBs). It appears to come back from a black gap forming surprisingly slowly after two stars merge, indicating a spot in our understanding of black holes.
There are two fundamental varieties of gamma ray bursts: quick GRBs, which final lower than 2 seconds and usually happen when two neutron stars smash collectively and collapse right into a black gap, and lengthy GRBs, which might final minutes and are related to supernovas. However GRB 211211A, noticed in 2021, doesn’t slot in that dichotomy.
4 separate analysis teams noticed the GRB, they usually all noticed the identical factor: it undoubtedly got here from two stars colliding, but it surely lasted about one minute. “Two seconds is how lengthy it takes in a merger for a black gap to kind and eat up every thing in its atmosphere, so it’s very unusual that this lasted a complete minute,” says Benjamin Gompertz on the College of Birmingham within the UK.
One of many groups urged the merger could have left behind an enormous, quickly rotating neutron star known as a magnetar, which could possibly be powering the gamma ray emission after the preliminary collision. The opposite three concluded that it almost definitely left behind a black gap, but it surely’s not clear how that would create such a protracted GRB.
“In these few moments between the merger of the neutron stars and the formation of the black gap, there’s a massive query mark proper now,” says Eleonora Troja at Tor Vergata College of Rome. “That is telling us that there’s a lacking piece of the puzzle that we didn’t even know was lacking.”
The lacking piece most likely has to do with the behaviour of the black gap itself, says Troja. “The black gap is just like the butler in against the law film – you know the way you watch against the law film or TV present and the primary suspect is all the time the butler? In astronomy, it’s the black gap, as a result of we all know that it has the flexibility to create issues that we don’t perceive,” says Troja.
Whereas GRB 211211A is by far the most important outlier from the GRB categorisations, it isn’t the one one. Different “oddball” GRBs haven’t been noticed so totally, although, so finding out this one will assist us perceive the others. “I’ve been calling this the Rosetta Stone of extended-duration GRBs as a result of it’s letting us join the physics to the observations in a lot worse datasets,” says Gompertz. We may have a 3rd class of GRBs for these bizarre occasions, the researchers say.
Journal references: Nature, DOI:10.1038/s41586-022-05327-3, DOI:10.1038/s41586-022-05403-8, DOI:10.1038/s41586-022-05404-7, DOI:10.1038/s41586-022-05390-w; Nature Astronomy, DOI:10.1038/s41550-022-01819-4
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