In a galaxy far, far away, a dwarf system known as IC 3418 is dying.
But astronomers say galaxy IC 3418's death will not be in vain -- after all, the dwarf elliptical galaxy's throes may provide invaluable insights into the way such systems evolve.
The galaxy is part of the Virgo Cluster, a group of more than a thousand galaxies relatively close to the group that contains the Milky Way. Researchers noticed IC 3418's "impending death" after spotting fireballs streaming from it into space, National Geographic reported.
The galaxy's colorful transformation is the first such death to be observed by astronomers.
“We think we’re witnessing a critical stage in the transformation of a gas-rich dwarf irregular galaxy into a gas-poor dwarf elliptical galaxy — the depletion of its lifeblood,” Dr. Jeffrey D.P. Kenney, a Yale University astronomy professor and principal investigator of a study on the galaxy, said in a statement. “Until now, there has been no clear example of this transformation happening.”
An ultraviolet image of dwarf galaxy IC 3418, with a trail of fireballs of gas appearing behind it.
Generally, dwarf galaxies like IC 3418 spend their prime creating generation after generation of stars, National Geographic noted. Eventually, however, they run out of the gases essential for this production, leading to their demise.
IC 3418 appears to be running on empty, having stopped star production 200 million to 300 million years ago, researchers said in a statement.
Now the galaxy is succumbing to something known as “ram pressure stripping” (when mixing gases build pressure, forcing out any remaining interior gas). This phenomenon, which was captured in 2009 by the Hubble Space Telescope, can distort the shape of the galaxies because the winds generated are so powerful, according to Wired.
“If you hold popcorn and unpopped kernels of corn in your hand and stick it out the car window as you drive, the wind caused by the car's motion through the air will blow away the popcorn but leave the denser unpopped kernels in your hand,” Kenney said in the statement. “This is like the gas clouds in galaxies being blown out of the galaxy by the wind of cluster gas, while the denser stars remain behind.”
Kenney presented his findings June 3 at a meeting of the American Astronomical Society in Indianapolis. His paper will be submitted to Astrophysical Journal.