标题： Swift时代的伽马射线暴的光学分类 显示英文标题

标题： Optical Classification of Gamma-Ray Bursts in the Swift Era

摘要： 我们提出一种新的方法，用于对光学暗弱伽马射线暴（GRB）进行分类，该方法基于伽马射线暴余辉的X射线和光学至X射线光谱指数，并利用Swift的光谱能力。 此方法比以前的方法更少依赖于模型假设，可以作为快速诊断工具来识别光学亮度较低的爆发。 通过这种方法，我们还可以发现光学波长极其明亮的伽马射线暴。 我们表明，之前提出的光学暗弱与X射线/伽马射线亮度之间的相关性仅仅是观测选择效应。 显示英文摘要

摘要： We propose a new method for the classification of optically dark gamma-ray bursts (GRBs), based on the X-ray and optical-to-X-ray spectral indices of GRB afterglows, and utilizing the spectral capabilities of Swift. This method depends less on model assumptions than previous methods, and can be used as a quick diagnostic tool to identify optically sub-luminous bursts. With this method we can also find GRBs that are extremely bright at optical wavelengths. We show that the previously suggested correlation between the optical darkness and the X-ray/gamma-ray brightness is merely an observational selection effect.