Extremely strong carbon monoxide emission from the Cloverleaf quasar at a redshift of 2.5
Extremely strong carbon monoxide emission from the Cloverleaf quasar at a redshift of 2.5
复制标题
红移为 2.5 的三叶草类星体发出极强的一氧化碳
作者：
R. Barvainis;L. Tacconi;R. Antonucci;D. Alloin;P. Coleman
高红移的星系是非常微弱的，很难在光学和近红外波段进行研究，但是在一个红移z = 2.3的星系中探测到远红外辐射1和分子气体2，3表明它们的早期演化可以通过这些手段来研究。类星体的宿主星系是这些观测的有希望的候选者，特别是类星体可能是由星系之间的相互作用和合并引发的，这导致了富含尘埃和气体的系统。三叶草是一种引力透镜类星体，具有远红外/亚毫米辐射，表明含有大量的尘埃6，因此可能含有大量的气体。在这里，我们报告的检测一氧化碳排放的立体式，我们解释为指示分子气体的质量，这是可比的总动力学质量的宿主星系，这是一致的重子总含量的一个现今的发光星系。这表明，尽管在宇宙当前年龄85%的回顾时间，立体式中已经发生了一些气体通过恒星的处理，但未来的大部分恒星内容尚未形成。
GALAXIES at high redshift are very faint and difficult to study at optical and near-infrared wavelengths, but detection of far-infrared emission1 and molecular gas2,3 in a galaxy at redshift z≈2.3 has suggested that their early evolution may be investigated by these means instead. The host galaxies of quasars are promising candi-dates for these observations, particularly as quasars might be triggered by interactions and mergers between galaxies4,5 which result in dust- and gas-rich systems. The Cloverleaf, a gravitation-ally lensed quasar, has far-infrared/submillimetre emission indicat-ing a substantial dust content6, and therefore potentially a large amount of gas. Here we report the detection of carbon monoxide emission from the Cloverleaf, which we interpret as indicating a mass of molecular gas that is comparable to the total dynamical mass of the host galaxy, and which is consistent with the total baryonic content of a present-day luminous galaxy. This suggests that, although some processing of gas through stars has taken place in the Cloverleaf at a lookback time of 85% of the current age of the Universe, much of the future stellar content has yet to be formed.