Mystery of ‘Double Galaxy’ After 8 Years; Dark Matter Most Likely The Culprit, Scientists Say

Astronomers have revealed the truth about a mystery "double" galaxy that first left them "stumped."

NASA's Hubble Space Telescope found the two galactic bulges that were mirror copies of each other along with another odd object nearby.

Astronomer Timothy Hamilton of Shawnee State University in Portsmouth, Ohio, said in a LiveScience report that they are completely baffled.

Now, Hamilton and his colleagues finally made a satisfying explanation and shared the details of the results in their study, titled "Hamilton's Object - A Clumpy Galaxy Straddling the Gravitational Caustic of a Galaxy Cluster: Constraints on Dark Matter Clumping."

Galactic Doppelgangers

Scientists found that the stretched pictures of a faraway galaxy more than 11 billion light-years away are linear objects.

They found distorted photos due to a previously unknown cluster of galaxies that were magnifying, illuminating, and stretching the image of the galaxy behind them due to their massive mass and its influence on spacetime.

In this unique, unusual occurrence, the perfect alignment between the background and foreground galaxy generated twin enlarged duplicates of the same image - with another, third, image to one side.

"Think of the rippled surface of a swimming pool on a sunny day, showing patterns of bright light on the bottom of the pool," Richard Griffiths, an astronomer at the University of Hawaii in Hilo, said in a statement.

A gravitational lensing-like phenomenon created these brilliant patterns on the bottom, Griffiths pointed out. He added that the ripples on the surface function as partial lenses. It focuses sunlight onto the bottom in brilliant squiggly patterns.

Solving An 8-Year-Old-Mystery

It was unknown what these items were when Hamilton initially discovered them in 2013, Space.com said. Researchers first thought that these objects were just interacting galaxies with tidally stretched-out arms. However, it didn't quite work.

Using spectroscopic data from the Gemini and W. M. Keck observatories, SciTechDaily said the scientists finally located the unusual cluster of galaxies generating the amplification and estimated the distance of the strange objects - which researchers later discovered to be the same galaxy.

They discovered that the dark matter surrounding the stretched pictures required to be 'smoothly' dispersed in space at small scales using specialized computer software. Jenny Wagner, a gravitational lensing expert from the University of Heidelberg in Germany, was glad that they only needed two mirror pictures to understand how clumpy or not dark matter may be at these locations.

Although it has been nearly a century since astronomers discovered dark matter, they still don't know what it is. However, Griffiths said the significance of size restrictions on the bunching or fluidity is that it gives scientists an idea of the constituent particle of dark matter. He added that the smaller the dark matter clusters, the bigger the particles must be.

Check out more news and information on Space in Science Times.