标题： LOTIS 上限值和GRB 990123的快速OT 显示英文标题

标题： LOTIS Upper Limits and the Prompt OT from GRB 990123

摘要： GRB 990123证实了伽马射线暴（GRBs）存在瞬时光学辐射。 自1996年10月以来，劳伦斯利弗莫尔光学瞬态成像系统（LOTIS）一直在自动搜索这种来自GRBs的同步低能辐射。 尽管LOTIS已经获得了几个GRBs的BATSE、IPN、XTE和BeppoSAX得到的误差框的同步或接近同步覆盖，但图像分析仅得出上限值。 GRB 990123独特的伽马射线特性，如非常大的通量（顶部0.4%）和硬谱，使与更典型的爆发进行比较变得复杂。 我们按比例调整并比较了LOTIS最佳事件的伽马射线特性，有时还包括余辉特性，以试图确定此事件的瞬时光学发射是否代表所有GRBs。 此外，利用LOTIS的上限值结合相对论激波模型，我们对GRB和余辉参数进行了弱约束，如爆破介质的密度和喷出物的整体洛伦兹因子。 显示英文摘要

摘要： GRB 990123 established the existence of prompt optical emission from gamma-ray bursts (GRBs). The Livermore Optical Transient Imaging System (LOTIS) has been conducting a fully automated search for this kind of simultaneous low energy emission from GRBs since October 1996. Although LOTIS has obtained simultaneous, or near simultaneous, coverage of the error boxes obtained with BATSE, IPN, XTE, and BeppoSAX for several GRBs, image analysis resulted in only upper limits. The unique gamma-ray properties of GRB 990123, such as very large fluence (top 0.4%) and hard spectrum, complicate comparisons with more typical bursts. We scale and compare gamma-ray properties, and in some cases afterglow properties, from the best LOTIS events to those of GRB 990123 in an attempt to determine whether the prompt optical emission of this event is representative of all GRBs. Furthermore, using LOTIS upper limits in conjunction with the relativistic blast wave model, we weakly constrain the GRB and afterglow parameters such as density of the circumburster medium and bulk Lorentz factor of the ejecta.