In the aspect of observations , fading X-ray , optical and radio afterglows , optical burst occurring during the gamma-ray emission , and the GRB host galaxies at cosmological distance are discovered .
观测上，人们发现了γ暴的低能余辉以及与γ射线爆发同时的光学爆发，还发现了它位于宇宙学距离的寄主星系。
cosmological distance