Astronomers led by Athanasia Tsatsi of the Max Planck Institute for Astronomy in Germany found that spindle-like galaxies; which rotate along their longest axis, are much more common than previously thought.
The new data allowed the astronomers to create a model for how these unusual galaxies probably formed, namely out of a special kind of merger of two spiral galaxies. The results have been published in the journal Astronomy & Astrophysics.
When most people think of galaxies, they think of majestic spiral galaxies like that of our home galaxy, the Milky Way: billions of stars, rotating in a flat disk similar to the way that a wheel rotates around its central axis.
But there is another kind of galaxy, which used to be thought very rare: so-called prolate rotators, each shaped like a cigar, which rotates along its long axis, like a spindle.
Using data from the CALIFA survey, a systematic study that examined the velocity structure of more than 600 galaxies, Tsatsi and her team discovered eight new prolate rotating galaxies, almost doubling the total known number of such galaxies (from 12 to 20).