Superluminous supernovae at redshifts of 2.05 and 3.90

摘要

A rare class of 'superluminous' supernovae that are about ten or more times more luminous at their peaks than other types of luminous supernova has recently been found at low to intermediate redshifts1'2. A small subset of these events have luminosities that evolve slowly and result in radiated energies of up to about 10~(51) ergs. Therefore, they are probably examples of'pair-instability' or 'pulsational pair-instability' supernovae with estimated progenitor masses of 100 to 250 times that of the Sun~(3-5). These events are exceedingly rare at low redshift, but are expected to be more common at high redshift because the mass distribution of the earliest stars was probably skewed to high values6'7. Here we report the detection of two superluminous supernovae, at redshifts of 2.05 and 3.90, that have slowly evolving light curves. We estimate the rate of events at redshifts of 2 and 4 to be approximately ten times higher than the rate at low redshift. The extreme luminosities of super-luminous supernovae extend the redshift limit for supernova detection using present technology, previously 2.36 (ref. 8), and provide a way of investigating the deaths of the first generation of stars to form after the Big Bang.%“超亮超新星”(比Ia-型超新星明亮十倍的恒rn星爆炸)只是在几年前才被发现的，在附近宇rn宙中也少见。现在，一项寻找高红移超新星的rn工作在红移值分别为2.05和3.90处发现了两rn个“超亮超新星”，它们都有慢慢变化的光曲rn线。这些发现意味着，在这些红移处“超亮超rn新星”的生成速度至少要比理论预测的附近宇rn宙中的生成速度大十倍。另外，所采用的搜寻rn技术也有在甚至更大的红移处发现“超亮超新rn星”的潜力--在那些红移处，天文学家将有rn可能看到“大爆炸”之后形成的第一代恒星的rn死亡情况。