The first deep-field image of the universe taken by the James Webb Space Telescope (JWST) has allowed scientists to study the faint phantom glow of orphaned intergalactic stars in galaxy clusters.
These stars are not gravitationally bound to the galaxy, they are separated from their homes and carried into intergalactic space by the enormous tidal forces that are generated between the galaxies of the cluster. The light from these orphan stars is called intracluster light and is so faint that only one percent of the brightness of the darkest sky is visible. a land.
Studying the spectral light of these orphan stars can not only reveal how galaxy clusters form, but could also give scientists clues about the properties dark mattera mysterious substance that makes up about 85% of the mass of the universe.
Dark matter doesn’t interact with light, which means scientists know it’s different from everyday matter proton And neutron. Its current existence can only be inferred from its gravitational interactions, which literally prevent galactic stars and planets from flying away.
JWST observes the universe in infrared light, the frequency of electromagnetic radiation that allows astronomers to see galaxy clusters differently than they are represented in visible light.
The sharpness of JWST’s infrared images allowed Interstellar Institute of the Canary Islands (IAC) researchers Mireia Montes and Ignacio Trujillo to study the light inside the galaxy cluster SMACS-J0723.3-7327 with a level of unprecedented detail.
This sharpness comes from the fact that JWST’s image of SMACS-J0723.3-7327, which is located about 4 billion light-years from Earth in the constellation Phulan, is twice as deep as observations of the same group previously taken by Hubble Space Telescope.
said study first author Montes V declaration (Opens in a new tab). “This will allow us to study galaxy clusters much deeper and in much more detail.”
Studying the low light within these clusters required more than JWST’s observation power, meaning the team also needed to develop new image analysis techniques. “In this work, we need to do some additional processing on the JWST images to be able to study the light inside the cluster, because the structure is stretched and dim,” Montes explained in the release. “This is key to avoiding bias in our measurements.”
The data the scientists obtained is strong evidence of the potential of light within a cluster to reveal the processes behind the formation of structures within galaxy clusters.
“By analyzing this scattered light, we found that the inner cluster was formed by the merger of massive galaxies, while the outer part was caused by the accumulation of galaxies similar to our own.” Milky WayMontes said.
Also, since the stars within a cluster are under the gravitational influence of the cluster as a whole rather than of individual galaxies, the light from these daughter stars provides the best way to study the distribution of dark matter in the cluster.
“The JWST test will allow us to characterize the distribution of dark matter in these massive structures with unprecedented precision and shed light on their fundamental properties,” added Trujillo, lead author of the two studies.
The duo’s research was released on Dec. 1 Astrophysics journal letter (Opens in a new tab).
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