Supernovas affect star formation in distant galaxies
doi:10.1038/nindia.2014.48 Published online 9 April 2014
Researchers have developed an analytical model to investigate the roles supernovas play in star formation in distant galaxies that are moving away from each other . This model will be useful for determining the relationship between star formation and supernova explosions for a large range of galaxies.
Supernovas are dying stars that explode violently by throwing out metals and other gaseous materials produced in galaxies. Since such outflows reduce the amount of gas available for the formation of a new generation of stars, they have a negative effect on star formation. Supernova explosions in low-mass galaxies result in more gas loss than those in galaxies with higher masses. Previous computer-based simulation studies had not pinned down the relationship between supernova explosions and star formation in distant galaxies.
To better understand the relationship between supernova explosions and star formation, the researchers devised an analytical model that used two feedback models. In one model, the thermal energy of supernova remnants drives outflows, whereas in the second model the momentum of hot gas drives outflows.
The researchers found that increasing the galaxy mass reduces the suppression of star formation. Massive galaxies check supernova-induced gas outflows, as they retain gas for star formation due to their large gravitational pull. Thus, supernova explosions in massive galaxies do not adversely affect star formation. In addition, the model demonstrates that supernova-induced outflows determine the mass of metal in a galaxy.
The researchers say that the analytical model predicts the star-formation history in galaxies at an early stage and then gradually reduces the star-formation history after a fraction of the dynamical time.
- Samui, S. Star formation in high redshift galaxies including supernova feedback: effect on stellar mass and luminosity functions. New. Astron. 30, 89-99 (2014)