Massive galaxy clusters as gravitational telescopes for distant supernovae

Résumé : We investigate the potential of using massive clusters as gravitational telescopes for searches and studies of supernovae of Type Ia and Type II in optical and near-infrared bands at central wavelengths in the interval 0.8-1.25 microns. Using high-redshift supernova rates derived from the measured star formation rate, we find the most interesting effects for the detection of core-collapse SNe in searches at limiting magnitudes m_lim~25-26.5 mag, where the total detection rate could be significantly enhanced and the number of detectable events is considerable even in a small field. For shallower searches, ~24, a net gain factor of up to 3 in the discovery rate could be obtained, and yet a much larger factor for very high source redshifts. For programs such as the GOODS/ACS transient survey, the discovery rate of supernovae beyond z~2 could be significantly increased if the observations were done in the direction of massive clusters. For extremely deep observations, m_lim > 27 mag, or for very bright SNe (e.g. Type Ia) the competing effect of field reduction by lensing dominates, and fewer supernovae are likely to be discovered behind foreground clusters.