By staring at the sky for over 200 hours, the Spitzer Space Telescope collected light that finally reached Earth after a 13-billion-year voyage through space.
This light left its origin so long ago that researchers studying this imagery are essentially peering back — way back — in time, to the ancient cosmic past.
Using Spitzer data, a research team observed 135 distant galaxies and found that these celestial bodies, which formed over 13 billion years ago and just 1 billion years after the Big Bang, were brighter than expected.
Researchers coupled their Spitzer findings with archival data from the Hubble Space Telescope in a recent paper published in the Monthly Notices of the Royal Astronomical Society.
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These 135 galaxies were particularly bright in two wavelengths of infrared light, which was created by radiation mingling with galactic gases like hydrogen and oxygen, according to a statement released May 9 — showing that the galaxies were releasing a high level of so-called ionizing radiation.