Posted in | Quantum Physics

'Green Pea' Dwarf Galaxy could hold key to Universe Evolution

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New research conducted by an intenrational team of scientists including a reseracher from the University of Virginia have discovered that newly formed dwarf galaxies were the likely reason for the universe heating up aeround 13 billion years ago.

Using data from an ultraviolet spectrometer aboard the Hubble Space Telescope, the team discovered a nearby compact dwarf galaxy emitting a large number of ionizing photons into the intergalactic medium, or the space between galaxies.

This galaxy appears to be an excellent local analog of the numerous dwarf galaxies thought to be responsible for the reionization of the early universe.

Trinh Thuan, Astronomer - University of Virginia

Despite 20 years of intensive searching, no galaxy emitting sufficient ionizing radiation had been found, and the mechanism by which the universe became re-ionized remained a mystery.

Hubble Space Telescope image of the compact green pea galaxy J0925+1403. The diameter of the galaxy is approximately 6,000 light years, and it is about twenty times smaller than the Milky Way. (NASA)

Using Hubble's UV radiation detecting capabilities, the research team found that the "green pea" galaxy J0925+1403, located at a distance of three billion light-years from Earth, was "ejecting" ionizing photons, with an intensity never seen before - about an 8 percent ejection.

As we make additional observations using Hubble, we expect to gain a much better understanding of the way photons are ejected from this type of galaxy, and the specific galaxy types driving cosmic reionization.

Trinh Thuan, Astronomer - University of Virginia

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