Paper detail

Near-IR search for lensed supernovae behind galaxy clusters: III. Implications for cluster modeling and cosmology

Massive galaxy clusters at intermediate redshifts act as gravitational lenses that can magnify supernovae (SNe) occurring in background galaxies. We assess the possibility to use lensed SNe to put constraints on the mass models of galaxy clusters and the Hubble parameter at high redshift. Due to the standard candle nature of Type Ia supernovae (SNe Ia), observational information on the lensing magnification from an intervening galaxy cluster can be used to constrain the model for the cluster mass distribution. A statistical analysis using parametric cluster models was performed to investigate the possible improvements from lensed SNe Ia for the accurately modeled galaxy cluster A1689 and the less well constrained cluster A2204. Time delay measurements obtained from SNe lensed by accurately modeled galaxy clusters can be used to measure the Hubble parameter. For a survey of A1689 we estimate the expected rate of detectable SNe Ia and of multiply imaged SNe. The velocity dispersion and core radius of the main cluster potential show strong correlations with the predicted magnifications and can therefore be constrained by observations of SNe Ia in background galaxies. This technique proves especially powerful for galaxy clusters with only few known multiple image systems. The main uncertainty for measurements of the Hubble parameter from the time delay of strongly lensed SNe is due to cluster model uncertainties. For the extremely well modeled cluster A1689, a single time delay measurement could be used to determine the Hubble parameter with a precision of ~ 10%. We conclude that observations of SNe Ia behind galaxy clusters can be used to improve the mass modeling of the large scale component of galaxy clusters and thus the distribution of dark matter. Time delays from SNe strongly lensed by accurately modeled galaxy clusters can be used to measure the Hubble constant at high redshifts.