What does it look like when the earth is bombarded with dark matter?
Experts have yet to fully explain the science behind the mysterious galaxy NGC 1
The discovery of NGC 1052-DF2 has led scientists to search for more galaxies of dark matter. What does the rare and mysterious DF2 galaxy really look like?
Dark matter is said to make up 27 percent of the cosmos, but the newly discovered DF2 galaxy has none of it.
New galaxy in the city
Diffuse galaxies have discovered a large, sparse galaxy in the northern constellation Cetus.
The mysterious galaxy is almost as big as the Milky Way, but has only 1 percent of its stars. The galaxy is nearly empty, except for packed stars, which move very slowly at an estimate of 18,000 miles per hour.
At least 10 very dense groupings of stars called globular clusters circled the center of the galaxy. The star clusters are an average of 20 light-years long and shine brighter than similar objects. The clusters looked almost as bright as the Omega Centauri, the brightest globular cluster in the Milky Way.
When scientists calculated the motion of the globular clusters, they discovered that the DF2 galaxy contained almost no dark matter.
What we know about the DF2?
On closer inspection with the Hubble Space Telescope and the Gemini Observatory, the scientists said that the DF2 looks like a diffuse blob, seeded with very compact star clusters with weak structures that nobody has seen before.
The DF2 is free of a dense central region or spiral extensions common in spiral galaxies. It also does not have a black hole, which is usually in the middle of most elliptical galaxies. Detailed images of DF2 showed no signs of interacting with other galaxies.
However, other galaxies can be seen through the DF2, giving it an almost ghostly look. The DF2 was previously cataloged, but in the new pictures it looked very different.
Scientists are completely confused with the DF2. It is now considered a candidate for a baryonic galaxy or galaxy without dark matter.
"There is no theory that predicts these types of galaxies," says Pieter van Dokkum, a researcher from Yale University. "The galaxy is a complete mystery because it's all weird about how to actually shape one of these things is completely unknown."
How was it discovered?
The astronomy team used object spectrographs and a custom-made telescope – the Dragonfly telephoto array to observe the DF2. van Dokkum and his comrade Roberto Abraham of the University of Toronto have built the telescope
The Dragonfly array consists of 48 telephoto lenses that are strong enough to see very faint celestial objects in the sky.
It was in 2015 that the team first observed the globular clusters that led to their discovery of the DF2. The team is now looking for other similar galaxies with dark matter.
van Dokkum and his team are now analyzing Hubble images of 23 diffuse galaxies. Three potential derivatives similar to DF2 will be followed up for investigation.
Based on the colors of the globular clusters, NASA estimates the DF2 galaxy to be around 10 billion years old.
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