GRB 210610B:The Internal and External Plateau as Evidence for the Delayed Outflow of Magnetar  

作　　者：Yi-Ning Wei Xiang-Gao Wang Da-Bin Lin Wei-Kang Zheng Liang-Jun Chen Sheng-Yu Yan Shuang-Xi Yi Qi Wang Zi-Min Zhou Hui-Ya Liu En-Wei Liang 韦逸宁;王祥高;林达斌;郑伟康;陈良军;闫圣钰;仪双喜;王琦;周子民;刘慧亚;梁恩维(Guangxi Key Laboratory for Relativistic Astrophysics,School of Physical Science and Technology,Guangxi University,Nanning 530004,China;GXU-NAOC Center for Astrophysics and Space Sciences,Nanning 530004,China;Department of Astronomy,University of California,Berkeley,CA 94720-3411,USA;Department of Physics and Tsinghua Center for Astrophysics(THCA),Tsinghua University,Beijing 100084,China;School of Physics and Physical Engineering,Qufu Normal University,Qufu 273165,China)

机构地区：[1]Guangxi Key Laboratory for Relativistic Astrophysics,School of Physical Science and Technology,Guangxi University,Nanning 530004,China [2]GXU-NAOC Center for Astrophysics and Space Sciences,Nanning 530004,China [3]Department of Astronomy,University of California,Berkeley,CA 94720-3411,USA [4]Department of Physics and Tsinghua Center for Astrophysics(THCA),Tsinghua University,Beijing 100084,China [5]School of Physics and Physical Engineering,Qufu Normal University,Qufu 273165,China

出　　处：《Research in Astronomy and Astrophysics》2024年第7期170-180,共11页天文和天体物理学研究（英文版）

基　　金：funded by the National Natural Science Foundation of China(Nos.12373042,U1938201,12273005 and 12133003);the Programme of Bagui Scholars Programme(WXG);support of the China Space Station Telescope(CSST)。

摘　　要：After launching a jet,outflows of magnetar were used to account for the achromatic plateau of afterglow and the early X-ray flux plateau known as“internal plateau”.The lack of detecting magnetic dipole emission together with the energy injection feature in a single observation poses confusion until the long gamma-ray burst(GRB)210610B is detected.GRB 210610B is presented with an optical bump following an early X-ray plateau during the afterglow phase.The plateau followed by a steep decline flux overlays in the steadily decaying X-ray flux with indexα_(X,1)~2.06,indicating an internal origin and that can be fitted by the spin-down luminosity law with the initial plateau luminosity log_(10)L_(X)~48.29 erg s~(-1)and the characteristic spin-down timescale T~2818 s.A subsequent bump begins at~4000 s in the R band with a rising indexα_(R,1)~-0.30 and peaks at~14125 s,after which a decay indexα_(R,2)~0.87 and finally transiting to a steep decay withα_(R,3)~1.77 achieve the closure relation of the external shock for the normal decay phase as well as the magnetar spin-down energy injection phase,provided that the average value of the photon indexΓ_γ=1.80 derived from the spectral energy distributions(SEDs)between the X-ray and optical afterglow.The closure relation also works for the late X-ray flux.Akin to the traditional picture of GRB,the outflow powers the early X-ray plateau by dissipating energy internally and collides with the leading decelerating blast burst as time goes on,which could interpret the exotic feature of GRB 210610B.We carry out a Markov Chain Monte Carlo simulation and obtain a set of best parameters:■.The artificial light curve can fit the afterglow data well.After that,we estimated the average Lorentz factor and the X-ray radiation efficiency of the later ejecta are 35%and 0.13%,respectively.

关 键 词：(stars)gamma-ray burst individual(GRB 210610B)-(stars)gamma-ray burst general-stars jets 

分 类 号：P172.3[天文地球—天文学]