16264

By measuring the time delay between any pair of gravitationally lensed images comma we can constrain the expansion rate of the universe and test dark energy models. Variable quasars have been used in this way with great success comma and it is now possible to extend this technique to gravitationally lensed supernovae (SNe). These targets are especially promising because their predictable light curves can deliver precise time delay measurements in a relatively short period. Existing surveys have a realistic chance of discovering at least one new lensed SN within the next 1-3 years. This long-term target of opportunity program will provide the high-resolution follow-up imaging that is critical for measuring a lensed SN time delay. This program will enable a time delay measurement with uncertainty of approximately +-3 days comma leading to a new measurement of H0 with a precision of 5-10% for a flat LambdaCDM cosmology---comparable to the best constraints achieved with lensed quasars. Future wide-field surveys (e.g. comma LSST comma WFIRST) could deliver hundreds of lensed SN time delays comma but the sample size will be limited by follow-up resources. This pilot study is an important step to establish lensed SNe as a competitive cosmological tool in the coming wide-field survey era.

通过测量任意一对引力透镜成像之间的时间延迟，我们可以约束宇宙的膨胀速率并检验暗能量模型。变类星体已被成功用于此类研究，如今该技术有望扩展至引力透镜超新星（SNe）。这类目标尤为具有前景，因其可预测的光变曲线能在相对较短时间内提供精确的时间延迟测量结果。现有巡天项目在未来1-3年内发现至少一颗新透镜超新星的可能性切实存在。这项长期机遇目标项目将提供高分辨率后续成像，这对测量透镜超新星的时间延迟至关重要。该项目将实现约±3天不确定性的时间延迟测量，进而对平坦LambdaCDM宇宙学模型下的H0进行精度为5-10%的新测量——这一精度可与透镜类星体研究获得的最佳约束相媲美。未来的广域巡天项目（如LSST、WFIRST）或可提供数百个透镜超新星的时间延迟数据，但样本量将受限于后续资源。这项试点研究是在即将到来的广域巡天时代将透镜超新星确立为具有竞争力的宇宙学工具的重要一步。