The early universe was a chaotic mess of gas and matter that only began to coalesce into distinct galaxies hundreds of millions of years after the Big Bang. It would take several billion more years for such galaxies to assemble into massive galaxy clusters — or so scientists had thought. Now astronomers have detected a massive, sprawling, churning galaxy cluster that formed only 3.8 billion years after the Big Bang, some 10 billion light years from Earth.
Astronomers harnessing the combined power of NASA’s Hubble and Spitzer space telescopes have found the faintest object ever seen in the early universe. It existed about 400 million years after the big bang, 13.8 billion years ago. The new object is comparable in size to the Large Magellanic Cloud (LMC), a diminutive satellite galaxy of our Milky Way.
The latest results from the “Cheshire Cat” group of galaxies 4.6 billion light-years away in the constellation Ursa Major show how manifestations of Einstein’s 100-year-old Theory of General Relativity can lead to new discoveries today. Astronomers have given the group this name because of its resemblance to the smiling feline from Alice’s Adventures in Wonderland.
A ripple in the outskirts of the Milky Way led Rochester Institute of Technology astrophysicist Sukanya Chakrabarti to a previously undetected dwarf galaxy hidden under a veil of dark matter. Now Chakrabarti is refining her technique to uncover dwarf galaxies and understand dark matter by simulating the evolutionary histories of galactic discs and their satellite populations.