The Perseus Cluster contains more than a thousand galaxies immersed in superheated gas that glows brightly in the X-ray spectrum. Over billions of years, this gas has accumulated the chemical signature of billions of supernova explosions. But when scientists compared its composition with theoretical models, it turned out that something was fundamentally off.
What the telescope revealed
The Hitomi (Astro-H) X-ray telescope, launched in 2016, conducted its only scientific observation of the Perseus Cluster before it failed. The data obtained proved invaluable: it measured the silicon, sulfur, argon, and calcium content in intergalactic gas with unprecedented precision.
The problem was that the theoretical models of the time predicted too much silicon and sulfur, but too little argon and calcium. These elements are produced primarily in massive stars at least ten times more massive than the Sun, so this discrepancy pointed to significant gaps in our understanding on the life and death of such stars.
New models, new timeline
An international team of researchers led by scientists from the Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU) at the University of Tokyo and the Netherlands Institute for Space Research (SRON) has developed updated models of massive stars and supernova explosions. In the first article of this series, they managed to identify the parameters under which the calculated chemical composition finally matched the observations.
In their second study, the researchers created a comprehensive catalog of stellar models for masses ranging from 15 to 60 solar masses and with varying initial chemical compositions, as determined by the star’s age in the Universe. By running this catalog through a model of the chemical evolution of galaxies, the team reconstructed a timeline spanning more than ten billion years, showing how supernova explosions gradually shaped the cluster’s chemical composition.
Jet supernovae and zinc
The third article focuses on a specific type of explosion that occurs when a massive celestial body is rotating. In such cases, the collapse of the core gives rise to a rapidly rotating black hole or neutron star, around which an accretion disk forms. Instability in the magnetized disk generates a powerful jet directed through the star’s atmosphere, and the explosion takes on a bipolar shape.
The team conducted a multidimensional simulation of this process and found that such events produce elevated levels of zinc. It is precisely this “chemical signature” that could serve as a key indicator for identifying instances of such extreme explosions in the early universe.
According to phys.org
