标题： 黑暗中的怪物：超亮伽马射线暴080607及其 dusty 环境 显示英文标题

标题： Monster in the Dark: The Ultraluminous GRB 080607 and its Dusty Environment

摘要： 我们给出了亮γ射线暴GRB 080607的早期光学至红外波段测光数据，这些数据从该暴初始触发后的6秒（静止参考系）开始记录。 结合我们之前发表过的光谱数据，这一高质量的测光数据集允许我们求解红移为3.036视线处的消光性质，提供了迄今为止关于本星系群外任一眼线的紫外连续吸收性质最详细的信息之一。 这些消光性质无法通过任何普通的消光模板（包括平均银河系、大麦哲伦云和小麦哲伦云曲线）充分建模，部分原因是2175埃特征（虽然存在）比在本地类似情况下弱大约两倍。 然而，局部星系群消光的更通用的Fitzpatrick & Massa（1990）参数化很好地拟合了这一光谱能量分布，将其归类于一些特殊银河系消光曲线的同一族。 在修正了这一显著的消光（A_V = 3.3 ± 0.4 mag）后，GRB 080607被揭示为有史以来观测到的最亮光学事件之一，与裸眼可见的爆发GRB 080319B相当。 其早期峰值时间（t_rest < 6 s）表明初始洛伦兹因子非常高（Γ > 600），而极端亮度可能部分由大爆后的高密度环境解释。 正是因为其早期的高亮度，在如此大的消光和距离下仍能对GRB 080607的余辉进行如此详细的观测，使这次爆发成为理解其他高度遮蔽的河外天体以及特别是“暗”GRB类别的极佳原型。 显示英文摘要

摘要： We present early-time optical through infrared photometry of the bright gamma-ray burst GRB 080607, starting only 6 s following the initial trigger in the rest frame. Complemented by our previously published spectroscopy, this high-quality photometric dataset allows us to solve for the extinction properties of the redshift 3.036 sightline, giving perhaps the most detailed information on the ultraviolet continuum absorption properties of any sightline outside our Local Group to date. The extinction properties are not adequately modeled by any ordinary extinction template (including the average Milky Way, Large Magellanic Cloud, and Small Magellanic Cloud curves), partially because the 2175-Angstrom feature (while present) is weaker by about a factor of two than when seen under similar circumstances locally. However, the spectral energy distribution is exquisitely fitted by the more general Fitzpatrick & Massa (1990) parameterization of Local-Group extinction, putting it in the same family as some peculiar Milky Way extinction curves. After correcting for this (considerable, A_V = 3.3 +/- 0.4 mag) extinction, GRB 080607 is revealed to have been among the most optically luminous events ever observed, comparable to the naked-eye burst GRB 080319B. Its early peak time (t_rest < 6 s) indicates a high initial Lorentz factor (Gamma > 600), while the extreme luminosity may be explained in part by a large circumburst density. Only because of its early high luminosity could the afterglow of GRB 080607 be studied in such detail in spite of the large attenuation and great distance, making this burst an excellent prototype for the understanding of other highly obscured extragalactic objects, and of the class of "dark" GRBs in particular.