Topic: Here’s see how Supermassive Black Holes are putting a brake on birth of the star
Source: ROYAL ASTRONOMICAL SOCIETY
Astronomers say that black holes with masses equal to millions of suns put the brakes on the birth of new stars. Using machine learning and three state-of-the-art simulations to back up the results of the Large Sky Survey, researchers resolved a 20-year-long debate over the formation of stars. Joanna Pietroska, a PhD student at the University of Cambridge, will present the new work at the Virtual National Astronomy Meeting (NAM 2021) today (Tuesday 20 July).
Star formation in galaxies has long been a focus of astronomy research. Decades of successful observation and theoretical modeling have resulted in our better understanding of how gas collapses to form new stars in and outside our own Milky Way.
However, thanks to all-sky observing programs such as the Sloan Digital Sky Survey (SDSS), astronomers realized that not all galaxies in the local universe are actively star-forming – there exist abundant populations of “silent” objects that Makes stars at a significantly lower rate.
The question of what stops star formation in galaxies remains the biggest unknown in our understanding of galaxy evolution, which has been debated over the past 20 years. Piotrowska and his team conducted an experiment to find out what might be responsible.
Using three state-of-the-art cosmological simulations – Eagle, Illustris and Illustris TNG – astronomers investigated what we would expect to see in the real universe, as observed by SDSS, when various physical processes inhibit star formation in giant galaxies. Was being
Astronomers applied a machine learning algorithm to classify galaxies into star-forming and quiescent, asking which of three parameters: the mass of the supermassive black holes found at the center of galaxies (the size of these monster objects). The mass is typically millions or billions of times that of our Sun), the total mass of the stars in the Milky Way, or the mass of the dark matter of the halo around galaxies, best predicts how galaxies turn out.
These parameters then enabled the team to figure out which physical process: energy injection by supermassive black holes, supernova explosions or shock heating of massive gas is responsible for forcing galaxies into quasi-retirement.
New simulations predict supermassive black hole mass as the most important factor in putting the brakes on star formation. Importantly, the simulation results matched observations of the local universe, adding weight to the researchers’ conclusions.
Pietroska says: “It’s really exciting to see how the simulations predict what we see in the real universe. Supermassive black holes – objects with masses equal to millions or billions of Suns – actually have a huge impact on their surroundings. These monster objects force their host galaxies into a kind of semi-retirement from star formation.”