Sparky, also called GOODS-N-774, is a young, massive galaxy observed by astronomers, forming far away from Earth. Millions of baby stars are being formed, igniting their thermonuclear reactions at a furious rate.
The Hubble Space Telescope, Herschel Space Observatory, and the Spitzer orbiting satellite were used to observe the developing family of stars. These observations were combined with data collected from the ground by astronomers at Keck Observatory in Hawaii.
The young galaxy is located 11 billion light years from Earth. Due to the finite speed of light, astronomers are seeing the formation as it existed just three billion years after the Big Bang. In the intervening eons, the formation likely formed into an elliptical galaxy, a collection of ancient stars.
Elliptical galaxies are poor in interstellar gases that fill other forms of galaxies. These stellar families form from the inside out, starting with the formation of a galactic core. Astronomers believe this process only took place soon after the formation of matter.
The Milky Way contains between 200 and 400 billion stars, spread over a disk 100,000 light years across. This young galaxy contains roughly twice as many stars as our own galaxy, packed into a collection just 6,000 light years in diameter.
"We really hadn't seen a formation process that could create things that are this dense. We suspect that this core-formation process is a phenomenon unique to the early universe because the early universe, as a whole, was more compact. Today, the universe is so diffuse that it cannot create such objects anymore," Erica Nelson from Yale University, lead author of the study, said.
Star formation in the young elliptical galaxy is also taking place at a rate of around 300 stars each year, roughly 30 times faster than observed in the Milky Way.
Dark matter, a mysterious substance that cannot be observed but exhibits gravitational effects on normal objects, like galaxies. Astrophysicists believe dark matter makes up nearly 27 percent of the mass of our Universe. The galactic core of the young, ultra-dense galaxy may be developing due to the gravitational influence of this elusive form of matter.
This was the first time astronomers have ever observed a massive, ultra-dense elliptical galaxy in the process of formation. Observations and study of the body could also provide valuable insight into the formation of galaxies in the young Universe.
Gas clouds orbiting around the center of Sparky were seen traveling at speeds never before seen in such bodies. This effect was predicted by theory, and observation of the phenomenon was prime evidence to identify the nature of the young galaxy.
Study of GOODS-N-774 was detailed in the journal Nature.
