Tag: reionization
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Ionizing the Universe with black holes and neutron stars
About 380,000 years after the Big Bang, the Universe cooled off enough for stable atoms to form out of the primordial plasma. However, sometime in the billion years or so after that, something happened to heat the gas up again, returning it to plasma form. Though we know reionization (as it is called) happened, that…
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Green Peas were all my joy, galaxies were my delight
Most galaxies are somewhat red or blue in appearance, depending on the populations of stars that comprise them. However, citizen scientists working with the GalaxyZoo project identified a previously unknown type of galaxy: Green Peas, so named because they are small and green. The color comes from ionized oxygen, a particular form of emission that…
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Early stars stole gamma rays from blazars
We have a lot of reasons to be interested in the earliest stars that formed in our Universe. Particularly, these stars were the first to fuse hydrogen and helium into (nearly) all the heavier elements that exist today, including the carbon, oxygen, iron, calcium, and the like that make up life as we know it.…