According to new research, the most massive spiral galaxies spin faster than scientists had originally expected, weighing 20 times more than the Milky Way.
As an average spiral galaxy, the Milky Way spins at a speed of 130 miles per second (210km/sec) in our Sun’s neighbourhood. According to new research, the most massive spiral galaxies spin faster than scientists had originally expected.
The largest of these ‘super spirals’ weighs around 20 times more than our Milky Way and spins at a rate of up to 350 miles per second (570km/sec). ‘Super spirals’ are unique in almost every way. In addition to being considerably larger than our Milky Way, they are also far brighter than our galaxy.
The largest ‘super spiral’ galaxy span 450,000 light-years compared to the Milky Way, which is 100,000 light-years in diameter. Only 100 of these super spiral have been discovered so far. These unique spirals were found as an important new class of galaxies while scientists were studying data from the Sloan Digital Sky Survey (SDSS) as well as the NASA/IPAC Extragalactic Database (NED).
“Super spirals are extreme by many measures…They break the records for rotation speeds.” says Patrick Ogle of the Space Telescope Science Institute in Baltimore, Maryland. Ogle is the first author of this paper, published in the Astrophysical Journal Letters. The paper demonstrates new data on the rotation rates of super spirals, the data was collected using the Southern African Large Telescope (SALT). Further data was obtained using the 5 metre Hale telescope of the Palomar Observatory which was operated by the California Institute of Technology. Crucial data for measuring the galaxy masses in stars and star formation rates was gathered by NASA’s Wide-field Infrared Survey Explorer (WISE) mission.
Referring to the new study, Tom Jarrett of the University of Cape Town, South Africa says, “This work beautifully illustrates the powerful synergy between optical and infrared observations of galaxies, revealing stellar motions with SDSS and SALT spectroscopy, and other stellar properties—notably the stellar mass or ‘backbone’ of the host galaxies—through the WISE mid-infrared imaging.”