Little red dot galaxies are now found in our local universe

A strange type of galaxy seen in the early universe has now seen in a newer part of the cosmos and raises questions about their nature.

Over the past few years, astronomers who use James Webb Space Telescope (JWST) have seen many small, compact and red items from the first billion years of the universe, known as Little Red Dots (LRDS). They were assumed to be linked to some process in the early universe, such as the birth of supermassive black holes found at the center of most galaxies, included ours.

Xiaojing Lin at Tsinghua University in China and her colleagues has now made an unusual discovery and found LRDs in the much newer universe, approx. 12 billion years after the Big Bang. “The discovery illustrates that conditions that give rise to small red dots are not exclusive to the early universe,” says Lin.

The team looked through photos taken by Sloan Digital Sky Survey using a telescope in New Mexico. They identified three objects seen by JWST that looked like LRDs, but, Crucialy, they were only up to 2.5 billion light years away.

“They fit each definition of small red dots,” says team member Xiaohui fan at the University of Arizona. “I don’t think there is any doubt that they are very similar.”

Each of the LRDs is estimated to be over a million time more massive than our sun sun, with a width that is similar to our solar system. One of them is called the “egg” because of its elongated form. The team also found a handful of other LRD candidates who have not yet been confirmed.

The discovery is exciting, says Anthony Taylor at the University of Texas in Austin because it could allow us to get unique information about the nature of the LRD. The objects are close enough that telescopes like JWST and Hubble should be a study of them much easier than LDS from the early universe, which is extremely weak, so they may reveal exactly what they are.

“They are much closer to us, so they go to show up very bright,” says Taylor.

One possible explanation of LRDs is that they resume the earning stages of a super -massive black hole that grows inside a galaxy, perhaps when it first turns on and starts violently eating material.

It is unclear where local LRDs would be galaxies that have so far been sleeping, or recently formed and have just begun to eat great love for material. “It’s too much to tell on that front,” says Taylor.

Fan says they hope to have time with Hubble or JWST to observe these local LRDs in more detail. “We have a suggestion for Hubble, we are waiting to be approved.”

It is possible that LRDs are also found through the history of the universe, not only the local and old cosmos. “They have been hidden in ordinary sight,” says Fan. “People just didn’t know what was looking for.”