Researchers have been able to capture the first-ever image of a dark matter web that confirms the existence of invisible matter in the universe.
The composite image of dark matter combines several individual images taken from thousands of pairs of galaxies and shows that dark matter is surrounding the galaxies and is connecting them to each other. However, the mysterious matter remained obscured until now.
“For decades, researchers have been predicting the existence of dark-matter filaments between galaxies that act like a web-like superstructure connecting galaxies together,” Mike Hudson, professor of astronomy at the University of Waterloo. “This image moves us beyond predictions to something we can see and measure.”
Dark matter makes up about 27 percent of the universe. But this substance has never been observed directly. Its presence is certainly felt because of the gravity it exerts on visible universe.
Unlike normal matter, dark matter is not in the form of visible objects such as stars and planets. Also, it does not interact with light which makes it extremely difficult to observe.
To create the first-ever image of dark matter, researchers stitched together lensing images from more than 23,000 galaxy pairs that are located 4.5 billion light-years away from Earth. By observing galaxy pairs, researchers also found that dark matter webs are strongest between the galaxies less than 40 million light years apart, providing clues on the distribution of dark matter within the systems.
Co-author Seth Epps from University of Waterloo says. “By using this technique, we’re not only able to see that these dark matter filaments in the universe exist, we’re able to see the extent to which these filaments connect galaxies together.”
Understanding dark matter may help explain how the universe is formed and how the galaxies are evolved.