Thursday, July 4, 2024

‘Little red dot’ galaxies are breaking theories of cosmic evolution

Do we really know anything?  We have galaxies and now we have little red dots that  may be galaxies.  Or are they deeply shifted galaxies that are far far away and happen to be seeable.

Our theoretical basis has always been a set of assumptions that new data questions directly.  this again is unexpected and not explainable using those assumptions.

If we understand that any galaxy is an act of creation and is all sublight, then what happens when photons pass through intergalactic space?  If the Galaxy is packed with a matrix acting as a photon carrier ,just what happens when it crosses to our galaxy?+

Can we ever know?

‘Little red dot’ galaxies are breaking theories of cosmic evolution

The James Webb Space Telescope has spotted hundreds of odd, distant galaxies that seem to either produce an impossible amount of stars or host black holes far more enormous than they should be

27 June 2024

This red blob is a distant galaxy with strange properties


The “little red dots” discovered by the James Webb Space Telescope (JWST) pose a cosmic conundrum. It seems that these compact galaxies are either stuffed impossibly full of stars or have black holes that are far too large. Either way, it presents problems for our views of galactic evolution.

When JWST started peering into the early universe, it found hundreds of tiny red galaxies everywhere it looked. Their existence alone was surprising, but as researchers dig into the data, they are finding that the properties of these galaxies, nicknamed little red dots, don’t make sense.

“There are a lot of these little red dots, and some of them are so bright, so very luminous, that they kind of defy what we expect,” says Hollis Akins at the University of Texas at Austin. He and his colleagues tested two possible sources of the light from these galaxies: starlight or the light from material falling into supermassive black holes at the galaxies’ centres.

They found that both potential solutions cause problems. If the light is dominated by stars, then little red dots must be churning out so many stars at such high rates that they should, in theory, give the modern universe much more mass than it has. If the light is dominated by black holes, then those black holes are far larger than we would expect to be possible, given the size of their host galaxies.

“Maybe it’s a mix of both – but even if you assume that half of the light is coming from supermassive black holes and half is coming from stars, you still get a problem because the sources are just everywhere,” says Caitlin Casey at the University of Texas at Austin. “It’s a real conundrum.”

In fact, Fabio Pacucci at the Harvard-Smithsonian Center for Astrophysics in Massachusetts and his colleagues found that even if only 1 per cent of the light from these galaxies comes from black holes, the black holes are still 10 to 100 times too big for their galaxies, based on what we know about the nearby universe. This could be an indication that supermassive black holes formed extraordinarily quickly in the early universe – that is the only way they could have gotten so large.

“It’s the typical chicken or egg question, if the galaxy formed first and the black hole then collapsed at the centre, or if the black hole formed first and then the galaxy assembled around it,” Pacucci says. The extreme masses of these black holes are the strongest evidence yet for the latter situation, he says.

“None of the pieces fit nicely using the common models of galaxies and black holes, meaning that we are probably missing something fundamental,” says Bingjie Wang at the Pennsylvania State University. “But no one has put forward a compelling new theory yet.”

Little red dots have several other strange properties, such as the old ages of their stars and their dimness in X-ray wavelengths, that also need explanations.

“It is really exciting to have a kind of object that we just don’t know how to explain,” says Jenny Greene at Princeton University. “But there are many ways out.” For example, if the black holes are devouring matter just a little bit faster than their modern counterparts do, it could alleviate some of the tension, she says.

JWST is poised to make more observations of little red dots over the next few years, and those should help scientists put the pieces together.

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