While astrophysicists from all over the world struggle to understand the origin of dark matter from many corners of the Universe, others are having a hard time figuring out where such a mysterious structure from a neighboring galaxy went.
Thanks to the Hubble Space Telescope that’s operated by NASA and ESA, an international team of scientists had a huge surprise back in 2018 when they found out that the galaxy known as NGC 1052-DF2 was lacking most of its dark matter. It was a premiere for science, as never before was found a galaxy from our own cosmic neighborhood that didn’t have the amount of dark matter expected. In 2019, another galaxy known as NGC 1052-DF4 was discovered, and it also lacked dark matter. This led to serious debates among scientists, who were trying to figure out more about these objects and why they are so different.
Eyes set on NGC 1052-DF4
The good old Hubble telescope was back in business once again and brought new data about the NGC 1052-DF4 galaxy that’slocated 45 million light-years away from Earth. Thanks to another international team of astronomers who analyzed the data and had Mireia Montes from the University of New South Wales in Australia as lead scientist, the conclusion was that effects of tidal disruption explain the missing dark matter. This translates that the gravity forces of the neighboring galaxy NGC 1035 are tearing NGC 1052-DF4 apart. Thus, the dark matter is removed from the latter galaxy. The scientists needed deep optical imaging for the discovery, and also the help of the Gran Telescopio Canarias (GTC) and the IAC80 telescopes from the Canary Islands of Spain.
Montes explains the role of the Hubble Space Telescope by saying:
We used Hubble in two ways to discover that NGC 1052-DF4 is experiencing an interaction,
This includes studying the galaxy’s light and the galaxy’s distribution of globular clusters.
The team member Ignacio Trujillo from the Instituto de Astrofísica de Canarias in Spain, also had something interesting to say:
This result is a good indicator that, while the dark matter of the galaxy was evaporated from the system, the stars are only now starting to suffer the disruption mechanism,
In time, NGC 1052-DF4 will be cannibalized by the large system around NGC 1035, with at least some of their stars floating free in deep space.
Dark matter plays a crucial role in galaxy formation and evolution. This mysterious form of matter helps the primordial gas to collapse and form new galaxies, and it also triggers the unexplainable motion of stars within galaxies.
The new findings were published in the Astrophysical Journal.