标题： 光学定位不明事件的识别：费米GBM GRB140801A案例 显示英文标题

标题： The optical identifcation of events with poorly defined locations: The case of the Fermi GBM GRB140801A

摘要： 我们报告了在费米伽马射线暴监测器(GBM) 137平方度$^2$3-$\sigma$误差箱内早期发现伽马射线暴（GRB）140801A的光学余辉。MASTER是唯一一个自动响应所有费米警报的观测站。GRB 140801A是少数几个光学对应体仅通过其GBM定位被发现的伽马射线暴之一。MASTER全球机器人网络在接收到警报后53秒发现了GRB 140801A的光学余辉，使其成为从GBM误差箱中检测到的最快光学伽马射线暴。使用10.4米加那利大型望远镜和SAO RAS的6米BTA获得的光谱揭示了$z=1.32$的红移。我们使用不同口径范围从0.4米到10.4米的望远镜对GRB 140801A进行了光学和近红外测光。在许多方面，GRB 140801A是一个典型的爆发。爆发的本征爆发光度和峰值能量分别为$E_\mathrm{iso} = 5.54_{-0.24}^{+0.26} \times 10^{52}$尔格和$E_\mathrm{p, rest}\simeq280$千电子伏特，这与Amati关系一致。光学光变曲线中没有喷流断裂提供了喷流半张角的一个下限$\theta=6.1$度。观测到的$E_\mathrm{peak}$与由Ghirlanda关系推导出的限制一致。联合费米GBM和Konus-Wind分析表明GRB 140801A可能属于中间持续时间类别。鉴于即将到来的大坐标误差箱区域的实验，GRB 140801A光学对应体的快速探测尤为重要。 显示英文摘要

摘要： We report the early discovery of the optical afterglow of gamma-ray burst (GRB) 140801A in the 137 deg$^2$ 3-$\sigma$ error-box of the Fermi Gamma-ray Burst Monitor (GBM). MASTER is the only observatory that automatically react to all Fermi alerts. GRB 140801A is one of the few GRBs whose optical counterpart was discovered solely from its GBM localization. The optical afterglow of GRB 140801A was found by MASTER Global Robotic Net 53 sec after receiving the alert, making it the fastest optical detection of a GRB from a GBM error-box. Spectroscopy obtained with the 10.4-m Gran Telescopio Canarias and the 6-m BTA of SAO RAS reveals a redshift of $z=1.32$. We performed optical and near-infrared photometry of GRB 140801A using different telescopes with apertures ranging from 0.4-m to 10.4-m. GRB 140801A is a typical burst in many ways. The rest-frame bolometric isotropic energy release and peak energy of the burst is $E_\mathrm{iso} = 5.54_{-0.24}^{+0.26} \times 10^{52}$ erg and $E_\mathrm{p, rest}\simeq280$ keV, respectively, which is consistent with the Amati relation. The absence of a jet break in the optical light curve provides a lower limit on the half-opening angle of the jet $\theta=6.1$ deg. The observed $E_\mathrm{peak}$ is consistent with the limit derived from the Ghirlanda relation. The joint Fermi GBM and Konus-Wind analysis shows that GRB 140801A could belong to the class of intermediate duration. The rapid detection of the optical counterpart of GRB 140801A is especially important regarding the upcoming experiments with large coordinate error-box areas.