Interacting systems give birth to a new galaxy
Astronomers have confirmed the existence of a galaxy that is 5 times larger than our own Milky Way, and interestingly that same system may also be a "parent" of a newly formed galaxy.
As we await human colonization of other planets in our solar system, astronomers and scientists are doing everything in their power to study not only other habitable planets but also other galaxies. In a collaborative effort, scholars have confirmed that NGC 6872 is the largest known spiral galaxy. Not only is the NGC 6872 barred spiral galaxy huge, but it’s so big that astronomers believe that it’s about 5 times larger than our very own Milky Way.
By combining various astronomical instruments from worldwide space exploration agencies, astronomers are saying that NGC 6872 spans more than 522,000 light-years from the tip of one spiral arm to the other.
(The circled region is believed to be the newly formed tidal dwarf)
The most intriguing part of NGC 6872 is actually not that it’s much bigger than the Milky Way, but rather NGC 6872’s interaction with a nearby disk galaxy (IC 4970). Astronomers believe that many systems, including our own, formed through acquisitions and merging, but the interaction between NGC 6872 and IC 4970 may have created a newer smaller galaxy instead.
“The northeastern arm of NGC 6872 is the most disturbed and is rippling with star formation, but at its far end, visible only in the ultraviolet, is an object that appears to be a tidal dwarf galaxy similar to those seen in other interacting systems,” says Duilia de Mello, professor of astronomy at Catholic University.
The tidal dwarf is brighter in ultraviolet, leading astronomers to believe that there are many young stars present within the newly formed galaxy.
“Understanding the structure and dynamics of nearby interacting systems like this one brings us a step closer to placing these events into their proper cosmological context, paving the way to decoding what we find in younger, more distant systems,” says Eli Dwek, a member of the team and a Goddard astrophysicist.