Investigating the Dark Universe through Gravitational Lensing - Cluster Lensing
by
Teresa Riehm(Stockholm University)
→
Europe/Stockholm
FB51
FB51
Description
Massive galaxy clusters act as powerful gravitational telescopes for extremely distant galaxies and supernovae (SNe). Detecting and studying SNe at very high redshifts (z > 1) is important for many reasons: through SN rate measurements, information can be obtained on the star formation rate in a redshift range where current theoretical predictions do not give consistent results; one will be able to discriminate between different progenitor scenarios for SNe of Type Ia as well as significantly increase the leverage of the current SN Ia Hubble diagram. In this talk, I will discuss the potential for detecting lensed supernovae behind massive clusters and report on recent SN discoveries from our surveys at VLT and NOT. In addition, I will show how, due to the standard candle nature of SN Ia, the direct information on the lensing magnification can be used to put constraints on the mass models of galaxy clusters. Furthermore, in the case of strongly lensed SNe, the time delay technique can be used to obtain an independent measurement of the Hubble parameter.
