'Cosmic lantern' could help us further understand the fate of the universe

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New research has provided a deeper insight into emission line galaxies, used in several ongoing and upcoming surveys, to help us further understand the composition and fate of the universe.

The quest to determine the nature of both dark matter and dark energy has led scientists to adopt new tracers of the large-scale structure of the universe, such as emission line galaxies. These galaxies present strong emission lines from the gas heated up by newly formed stars.

Lead author of the study, Dr. Violeta Gonzalez-Perez from the University's Institute of Cosmology and Gravitation, said: "Galaxies are cosmic lanterns that show small patches of cosmic history, informing us of the changes in the space-time fabric of the universe. The strong formation of new stars in galaxies leave a characteristic imprint in their spectra that allows for a precise determination of their distance.

"Moreover, as young stars are very bright, galaxies with a strong star formation can be visible further back in cosmic time. These are the two characteristics that make emission line galaxies excellent cosmological tracers for a long time span."

Source

 

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Credit: NASA, ESA and The Hubble Heritage (STScl/AURA)-ESA/Hubble Collaboration.

Nearby emission line galaxies NCG 4038 – 4039. The pink parts in this image are showing the light from the gas heated by newly formed stars.

Source / Image Courtesy

 

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Credit: University of Portsmouth

The location of some the emission line galaxies observed in the study (green circles) against the images of a big patch of the sky as observed by The Dark Energy Camera Legacy Survey

Source / Image Courtesy

 

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One of the first images from the ESO VIMOS facility, obtained right after the moment of "first light" on February 26, 2002. It shows the famous "Antennae Galaxies" (NGC 4038/9), the result of a recent collision between two galaxies.

As an immediate outcome of this dramatic event, stars are born within massive complexes that appear blue in this composite photo, based on exposures through green, orange and red optical filters.

 

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Zoom into the Antennae Galaxies.