The rates and time-delay distribution of multiply imaged supernovae
  behind lensing clusters
  Time delays of gravitationally lensed sources can be used to constrain the
mass model of a deflector and determine cosmological parameters. We here
present an analysis of the time-delay distribution of multiply imaged sources
behind 17 strong lensing galaxy clusters with well-calibrated mass models. We
find that for time delays less than 1000 days, at z=3.0, their logarithmic
probability distribution functions are well represented by P (log \Delta t)=5.3
x 10^-4 \Delta t^\beta M_250^-2\beta, with \beta=0.77, where M_250 is the
projected cluster mass inside 250 kpc (in 10^14 M_sun), and \beta is the
power-law slope of the distribution. The resultant probability distribution
function enables us to estimate the time-delay distribution in a lensing
cluster of known mass. For a cluster with M_250=2 x 10^14 M_sun, the fraction
of time delays less than 1000 days is approximately 3%. Taking Abell 1689 as an
example, its dark halo and brightest galaxies, with central velocity
dispersions larger than 500 km/s, mainly produce large time delays, while
galaxy-scale mass clumps are responsible for generating smaller time delays. We
estimate the probability of observing multiple images of a supernova in the
known images of Abell 1689. A two-component model of estimating the supernova
rate is applied in this work. For a magnitude threshold of m_AB=26.5, the
yearly rate of Type Ia (core-collapse) supernovae with time delays less than
1000 days is 0.004 +- 0.002 (0.029 +- 0.001). If the magnitude threshold is
lowered to m_AB ~ 27.0, the rate of core-collapse supernovae suitable for time
delay observation is 0.044 +- 0.015 per year.
