What influence can black holes have on a galaxy’s formation and evolution? This is what a recent study published in Nature Astronomy hopes to address as an international team of researchers used NASA’s James Webb Space Telescope to observe a Milky Way-sized galaxy called “Pablo’s Galaxy” that existed approximately two billion years after the Big Bang to better understand why stars within this galaxy have stopped forming. This study holds the potential for researchers to better understand the formation and evolution of galaxies in the early universe and what this means for our galaxy in the future.
“Based on earlier observations, we knew this galaxy was in a quenched state: it’s not forming many stars given its size, and we expect there is a link between the black hole and the end of star formation,” said Dr. Francesco D’Eugenio, who is a research associate at Cambridge University’s Kavli Institute for Cosmology and is a co-author on the study. “However, until Webb, we haven’t been able to study this galaxy in enough detail to confirm that link, and we haven’t known whether this quenched state is temporary or permanent.”
The researchers found the black hole at the center of Pablo’s Galaxy is expelling gas at such a rate that it escapes the galaxy’s gravitational influence. As a result, this now-expelled gas is preventing the galaxy from forming new stars, with the black hole essentially “starving” the galaxy. This marks the first time that scientists have observed such activity, which had only existed in theoretical models until now.
Image of GS-10578 aka Pablo’s Galaxy obtained by NASA’s James Webb Space Telescope, which displays how this galaxy’s supermassive black hole is “starving” the galaxy of dust needed to create new stars. (Credit: Francesco D'Eugenio)
Going forward, scientists plan to use the Atacama Large Millimeter-Submillimiter Array (ALMA) to conduct further observations of the gas within Pablo’s Galaxy to ascertain if enough gas is present to allow for star formation, along with ascertaining how this black hole’s behavior is influencing the environment just outside the galaxy.
What new discoveries about galaxy-starving black holes will researchers make in the coming years and decades? Only time will tell, and this is why we science!
As always, keep doing science & keep looking up!
Sources: Nature Astronomy, EurekAlert!