Galaxies are vast systems of stars, gas, and dust held together by gravity. They come in a variety of shapes and sizes, and they evolve over time. Some galaxies are actively forming new stars, while others are inactive, or "quenched." Quenched galaxies are thought to be the end point of galaxy evolution, and astronomers are still trying to understand how this quenching process works.
One possible mechanism for quenching star formation is the presence of a supermassive black hole (SMBH) at the center of the galaxy. SMBHs are thought to be present in most, if not all, massive galaxies, and they can have a profound effect on the surrounding galaxy. The gravity of the SMBH can pull in gas and dust, which can then heat up and form new stars. However, the SMBH can also expel gas and dust from the galaxy, which can prevent star formation from happening.
The team of researchers from the IAC observed a large sample of massive, inactive galaxies using the Atacama Large Millimeter/submillimeter Array (ALMA). ALMA is a powerful telescope that can detect the faint light emitted by cold gas and dust. The team found that galaxies with a more massive SMBH had a lower star formation rate than galaxies with a less massive SMBH. This suggests that the SMBH is playing a role in quenching star formation in these galaxies.
The researchers also found that the galaxies with a more massive SMBH had a higher molecular gas content than galaxies with a less massive SMBH. Molecular gas is the raw material for star formation, so this suggests that the SMBH is not completely preventing star formation from happening. Instead, it seems that the SMBH is regulating the rate of star formation.
These findings provide new insights into the quenching of star formation in galaxies. The presence of a SMBH seems to be a key factor in quenching star formation, but the exact mechanism by which this happens is still not fully understood. Further studies are needed to investigate the role of SMBHs in galaxy evolution.
