July 25, 2024

Artist's concept of MACS J0018.5 with dark matter in blue and baryonic matter in orange (Image courtesy W.M. Keck Observatory/Adam Makarenko)

An article published in the journal “The Astrophysical Journal” reports the results of a study on the ongoing merger between two galaxy clusters that are forming a single new cluster cataloged as MACS J0018.5+1626, or simply MACS J0018.5. A team of researchers used data obtained from observations dating back even decades conducted with various space and ground-based telescopes, analyzing them to decouple the behavior of ordinary matter and dark matter.

To measure the speed of intergalactic gas composed of normal matter, they used the kinematic Sunyaev-Zel’dovich (SZ) effect. The speed of dark matter is roughly the same as galaxies. The result is that dark matter moves faster than normal matter. This result offers clues about dark matter and its behavior that are useful in studies of its nature.