Thesis defense [before December 2013]

Master Thesis: Transient detection and supernova rates

by Tor Kjellsson (Stockholm University, Department of Physics)

Europe/Stockholm
A5:1041

A5:1041

Description
Type Ia Supernovae (SNe Ia) are extremely bright objects with small intrinsic brightness dispersion, making them suitable for measuring cosmological distances. It is of great interest to search for distant SNe Ia since they are crucial for studying dark energy and could eventually provide observational evidence for a deviation form a cosmological constant. Another application lies in the role SN formation rates (SR) have for understanding galaxy evolution. In 2009 a transient survey was carried out using the Very Large Telescope to search for SNe in the near-infra red (NIR) by targeting massive galaxy clusters. The authors presented predictions for the SR for various types of SNe and their findings during their campaign matched the predictions in a promising way. One input variable in their prediction was the detection efficiency of the images, an estimate of the magnitude of objects that can be detected with a certain percentage of efficiency. In this thesis we investigate the detection efficiency of a new, more extensive survey, using simulations that have been further developed. We simulate SNe and study how the efficiency varies with the brightness of the fake objects. The results are then used to: i) study how differences in the background light may affect the detection efficiency ii) compute the expected number of SNe to be found in the new survey. We also search for an expression for our efficiency curves with physical interpretation.