NASA finds 'galactic fossil' in a galaxy 13 million light years away

NASA scientists have identified unexpectedly massive clouds of cold gas within the spiral galaxy NGC 4945, located 13 million light years away. As per the release, the revelation of this cold gas serves as the discovery of a "galactic fossil." The observations suggest that the gas likely rushed through this galaxy following the outburst from its supermassive black hole some five million years ago.

The scientific team suggests that this highlighted cold gas is possibly an ancient remnant of a particle jet emitted by this black hole lurking at the center of this galaxy. These recent findings have the potential to provide insights into the broader understanding of galaxy evolution. “There’s ongoing debate in the scientific community about how ,” said Kimberly Weaver, an astrophysicist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

“We find supermassive black holes in the centers of nearly all Milky Way sized galaxies, and an open question is how much influence they have compared to the effects of star formation. Studying nearby galaxies like NGC 4945, which we think we’re seeing in a transition period, helps us build better models of how stars and produce galactic changes,” explained Weaver.

Observations were conducted using two X ray facilities NGC 4945 has been classified as an active starburst galaxy with a substantially greater star production rate than the Milky Way. Interestingly, the galaxy can produce "the equivalent mass of 18 stars like our Sun every year." NASA scientists conducted observations of this active galaxy using ESA's satellite XMM Newton (X ray Multi Mirror Mission) and NASA's Chandra X ray Observatory.

The data indicated the "iron K alpha line," which stretched well beyond the galaxy's core. As per the release, this signature line appears from the interaction between highly energetic X ray light from the black hole's disk and cold gas in the distant surroundings. The temperature of cold gas The team gauged the temperature of this cold galactic gas, roughly 400 degrees Fahrenheit or minus 200 Celsius.

“Chandra has mapped iron K alpha in other galaxies. In this one, it helped us study individual bright X ray sources in the cloud to help us rule out other potential origins besides the black hole,” said Jenna Cann, a co author and postdoctoral researcher at Goddard. “But NGC 4945’s line extends so far from its center that we needed XMM Newton’s wide field of view to see all of it,” added Cann in the .

The findings indicated that this identified jet produced a powerful wind that continually pushed cold gas through the galaxy. Scientists even propose that it may help birth new stars in this galaxy. The team will continue to monitor this galaxy using high tech telescopes to uncover how this colossal black hole is influencing the galaxy’s overall evolution.

The study's authors presented their findings at the American Astronomical Society's 243rd conference in New Orleans on January 11. The work is likely to be published in.