Stellar population gradients of SAMI central galaxies

Galaxy mergers play an important role in how galaxies evolve over time, however extragalactic astronomers do not yet totally understand the process by which those mergers happen. The brightest galaxies of groups and clusters are extremely luminous galaxies, usually located in the centres of those systems – central galaxies. Simulations predict that these central galaxies have undergone more mergers than other similarly luminous galaxies, making them an excellent test of the merger process. The recent merger history of galaxies can be read through their stellar population gradients. Central galaxies with active merger histories are predicted to have shallower metallicity gradients than satellite galaxies of a similar mass. We examined the stellar population gradients (age, metallicity and alpha-element abundance ratios) of central galaxies in the SAMI galaxy survey to determine whether they are offset from similarly massive satellite galaxies in order to reach a better understanding of the role of mergers in galaxy formation and evolution.