Tour: NASA Connects Little Red Dots With Chandra, Webb
(Credit: NASA/CXC/A. Hobart)
[Runtime: 03:05]

With closed-captions (at YouTube)

A newly discovered object may be a key to unlocking the true nature of a mysterious class of sources that astronomers have found in the early universe in recent years.

Shortly after NASA’s James Webb Space Telescope started its science observations, reports of a new class of mysterious objects emerged. Astronomers found small, red objects that are about 12 billion light-years from Earth or farther that became known as “little red dots,” or LRDs.

Many scientists think LRDs are supermassive black holes embedded in clouds of dense gas, which mask some of the typical signatures in different kinds of light — including X-rays — that astronomers usually use to identify them. This would make them different from typical growing supermassive black holes, which are not embedded in dense gas, allowing bright ultraviolet light and X-rays from material orbiting the black holes to escape.

Because of this and their potential similarities to stellar atmospheres, astronomers have called this the “black hole star” scenario for LRDs.

This new object discovered by Chandra is exciting because it is the first LRD that is known to give off X-rays. Because of that, the astronomers who found this object nicknamed it the “X-ray dot.”

Located about 11.8 billion light-years from Earth, the X-ray dot may provide a crucial bridge between black hole stars and typical growing supermassive black holes. It exhibits most of the features of an LRD, including being small, red, and located at a vast distance, but it glows in X-ray light, unlike other LRDs.

Finding a little red dot that does gives researchers important new insight into what could power them. The researchers suggest that the X-ray dot represents a transition phase from an LRD to a typical growing supermassive black hole. As the black hole star consumes its surrounding gas, patchy holes in the clouds of gas appear. This allows X-rays from material falling onto the black hole to poke through, which are observed by Chandra. Eventually all the gas is consumed, and the black hole star ceases to exist.

The astronomers were only able to find this X-ray emitting little red dot by comparing new surveys from James Webb with deep observations from Chandra. They will continue to combine the data from these two powerful observatories to look for more examples of this behavior to hopefully help further unravel the mysteries surrounding little red dots.

Quick Look: NASA Connects Little Red Dots With Chandra, Webb
(Credit: NASA/CXC/A. Hobart)
[Runtime: 00:46]

With narration (video above with voiceover)

A new discovery from NASA’s Chandra may explain a recent mystery in astrophysics.

After the launch of NASA’s James Webb, a new class of faint, distant objects was found.

Chandra spotted one of these “little red dots” that gives off X-rays unlike the others.

This suggests that there may be a new phase of growing supermassive black holes.