A group of physicists and computer scientists from the Argonne National Laboratory, belonging to the United States Department of Energy, made one of the largest cosmological simulations carried out to date. An article about the process was published on Wednesday (27) in the journal Astrophysical Journal Supplement Series.

Called Last Journey (from English Last Journey), the simulation was performed by supercomputer Mira. The machine was launched by the same team of scientists in 2013, in the Outer Rim cosmological simulation. Since then, Mira has been used in other studies and the Last Day marks its last activity before the definitive shutdown.


Origin of dark matter

The study gathers data that can help in the preparation of spatial maps and in large-scale cosmological experiments. One of the main objectives of the project is to understand how gravity produces substances that are still mysterious to science, such as dark matter, for example.

The origin of dark matter is cause for speculation in the scientific community. This is because it is a substance that does not interact with common materials and has a primary function in the gravitational system of galaxies.

The Last Journey follows the distribution of matter in the universe over time. Therefore, it will allow us to understand how dark matter huddles into large-scale structures called halos (or halos, in English). It is in these systems that galaxies are born and develop.

In the simulation, scientists identify where the particles of matter are at a given point in time. Thus, it is possible to point out the structure formed and store a relevant amount of data that will contribute to future research and experiments.


The data accumulated in the Last Journey will be used as material for several scientific experiments. Among them are the Legacy Survey of Space and Time, organized by Rubin Observatory in Chile, the Dark Energy Spectroscopic Instrument and two NASA missions, the Roman Space Telescope and SPHEREx.

Katrin Heitmann, director of Argonne's High Energy Physics (HEP) division, says the team studied a large volume of the universe. “We were interested in large-scale structures, such as regions with thousands or millions of galaxies, but we also analyzed cases at smaller scales”, he comments.

The six months required for the simulation and analysis tasks of the Last Journey represented challenges for software development and workflow. For this, the team adapted part of the software used in the Outer Rim simulation in order to make the use of Mira more efficient. Scientists are expected to publish new articles on the project in the coming months.

Source: Phys.Org