Using the Atacama Large Millimeter/submillimeter Array (ALMA), of which ESO is a partner, astronomers have discovered a large reservoir of hot gas in the still-forming galaxy cluster around the Spiderweb galaxy — the most distant detection of such hot gas yet. Galaxy clusters are some of the largest objects known in the Universe and this result, published today in Nature, further reveals just how early these structures begin to form.
This research was presented in the paper “Forming intracluster gas in a galaxy protocluster at a redshift of 2.16” to appear in Nature (doi: 10.1038/s41586-023-05761-x).
Image: © ESO/H. Ford; This image shows the protocluster around the Spiderweb galaxy (formally known as MRC 1138-262). The light that we see in the image shows galaxies at a time when the Universe was only 3 billion years old. Most of the mass in the protocluster does not reside in the galaxies, but in the gas known as the intracluster medium. Because of the mass in the gas, the protocluster is in the process of becoming a massive cluster held together by its own gravity.