伽玛暴光学余辉中的双喷流成份行为

Searching GRBs with two components jet in Gamma-ray bursts optical afterglow

伽玛暴余辉的双拐折行为可以用双喷流成份结构模型得到较好的解释,但至今其物理参数还未解.为给出其相应的物理参数,文中将对具有双喷流成份的伽玛暴光学余辉进行统计分析,用外激波模型时域指数α和频域指数β的关系（closure relation）对数据进行限制,得到 GRB 071003,GRB 080319B,GRB 090426和GRB 100219A共4个具有外激波模型的伽玛暴双成份喷流特征.这些伽玛暴第一个喷流成份的张角都在1°以内,而第二个喷流成份的张角增大到2°-7°,与单成份喷流的张角一致.其各向同性辐射能量在1051ц1054 erg,电子谱指数p约为2,比典型值2.3硬.长暴能较好符合Amati关系.

Two components jet model can interpreter the behaviors of two breaks for gamma-ray bursts （ GRBs） afterglow. The two components jet break in the optical afterglow is studied is this work. A completed well-sample optical light-curves were included, using the empirical fitting andα-β closure relation of external forward shock model. 4 GRBs （ GRB 071003,GRB 080319B,GRB 090426 and GRB 100219A） are claimed as two components jets of the external forward shock mod-el. All of the jet opening angle of the first component is smaller than 1°,and they increase to 2°ц7° for the second component, which is consistent with the single component jet GRBs. The isotropic equivalent radiation energies vary from 1051 erg to 1054 erg and the electron spectral index p is about＆amp;nbsp;2 , which is harder than the typical value of p=2 . 3 . The three long duration GRBs （ GRB 071003 , GRB 080319B and GRB 100219A） are consistent with the Amati relation.