Fugusto 2009 有个高能的探测到的伽玛暴可能只是噪声

主要内容:
叫做"sunset enhancement", 就是在傍晚的时候会有高能的增亮现象, 可能被伽玛暴探测器当做伽玛暴了. 文章给了两个例子. 不过要是统计一下是不是每次探测器碰到傍晚光变就增亮, 或者统计一下各个暴的探测时间, 看是不是有很大一部分暴是在"傍晚"观测到的, 就更能说明问题了.

sunset enhancement的原理没看懂.

精彩摘抄:


文章信息:

arXiv:0901.1832 [ps, pdf, other]

Title: Gamma ray burst triggers at daytime and night-time interface

Authors: C. R. A. Augusto, J. B. Dolival, C. E. Navia, K. H. Tsui

Comments: 6 pages, 9 figures

Subjects: Astrophysics (astro-ph)

There is a difference between the solar ionization concentration in the ionosphere in the daytime and at night-time. At night the E-region ion concentration peak is dramatically reduced due to chemical losses and the rapid change in the vertical polarization electric field at the time around sunset, which is due to the accelerating neutral wind dynamo and which produces a corresponding change in the zonal electric field through curl-free requirements. The result is the formation of a layer of high conductivity, at the daytime-night-time interface. This phenomenon in the South Atlantic Anomaly (SAA) area, provokes an increase in the precipitation of charge particles which is well known and is commonly termed "sunset enhancement". In the following we show that some gamma ray burst (GRB) triggers observed by spacecraft GRB detectors such as INTEGRAL, AGILE, and Fermi are probably noise triggers, produced by omni-directional particle precipitation, because they are in temporal coincidence with muon enhancement observed at ground level by the Tupi telescopes with different orientations at $\sim 21$ UT (local sunset), and located inside the SAA region.