中文摘要：

某些伽玛射线暴（简称伽玛暴）的中心致密天体可能是一颗具有强磁场的毫秒脉冲星，它通过磁偶极辐射可对伽玛暴外激波注入能量，从而导致早期余辉光变曲线的变平．近年来，从Swift卫星观测到的大量伽玛暴x射线余辉中发现，很多x射线余辉光变曲线在暴后10^2-10^4S期间的确存在明显的变平现象．利用周期为毫秒量级的磁星能量注入模型对11个伽玛暴的x射线余辉光变曲线进行了拟合，显示该模型在解释余辉变平现象上的有效性和广泛性，通过对余辉光变曲线的拟合，同时也给出了相关中心磁星的磁场强度和旋转周期．

英文摘要：

The central compact object of some gamma-ray bursts （GRBs） may be a strongly magnetized millisecond pulsar. In this model, there is an energy injection from the pulsar to the external forward shock through the magnetic dipole radiation. The energy injection would give rise to the shallow decay of the early afterglow. Recently, an interesting feature is discovered from many X-ray afterglows observed by Swift/XRT （X-ray Telescope）： the shallow decay of some X-ray afterglows happens about 10^2 - 10^4 s after the prompt emission. We have fitted 11 X-ray afterglow lighteurves of GRBs by using the magnetar energy injection model. The result shows the validity and universality of the Inagnetar energy injection model in explaining the post-shallow-decay phenomenon. Our fittings provide some constraints on the magnetic strength and the rotation period of the central magnetar.