Astronomers Discover Super Spiral Galaxies
A new study using archived NASA data reveals a new kind of galactic beast. Dubbed “super spirals,” these galaxies dwarf our own Milky Way and compete in size and brightness with the largest galaxies in the universe.
“We have found a previously unrecognized class of spiral galaxies that are as luminous and massive as the biggest, brightest galaxies we know of,” said Patrick Ogle, an astrophysicist at the Infrared Processing and Analysis Center (IPAC) at the California Institute of Technology in Pasadena and lead author of a new paper on the findings published in The Astrophysical Journal.
“It’s as if we have just discovered a new land animal stomping around that is the size of an elephant but had shockingly gone unnoticed by zoologists.”
Ogle and colleagues came upon super spirals as they searched for extremely luminous, massive galaxies.
“Remarkably, the finding of super spiral galaxies came out of purely analysing the contents of the NASA/IPAC Extragalactic Database, thus reaping the benefits of the careful, systematic merging of data from many sources on the same galaxies,” study co-author George Helou, executive director of IPAC, said.
The researchers expected that humongous, mature galaxies called ellipticals would dominate their search within NED for the most luminous galaxies. But a tremendous surprise lay in store for the scientists.
In a sample of approximately 800,000 galaxies no more than 3.5 billion light-years from Earth, 53 of the brightest galaxies intriguingly had a spiral, rather than elliptical shape.
Super spirals can shine with anywhere from eight to 14 times the brightness of the Milky Way and possess as much as 10 times our galaxy’s mass.
Their gleaming, starry disks stretch from twice to even four times the width of the Milky Way galaxy’s approximately 100,000 light-year-wide disk, with the largest super spiral spanning a whopping 440,000 light-years.
According to established astrophysical theory, spiral galaxies should not be able to attain any of these feats because their size and star-making potential are limited.
“Super spirals could fundamentally change our understanding of the formation and evolution of the most massive galaxies,” said Ogle. “We have much to learn from these newly identified, galactic leviathans.”