AI 中文总结
本研究对高能长时标伽马暴ZTF20abbiixp/GRB 200524A开展多波段分析，定制结合正反激波的余辉模型拟合数据，揭示其低光谱滞后等特殊性质及致密ISM环境特征。
AI 中文摘要
我们对费米伽马射线暴监测器（Fermi GBM）探测到的高能长时标事件ZTF20abbiixp/GRB 200524A开展了全面的多波段分析。本研究结合了费米（Fermi）等多个空间望远镜的扩展高能观测数据，以及从X射线到射电波段的宽带余辉数据，还辅以全球多个地面光学设备（如3.6米德瓦斯塔尔光学望远镜DOT）的大量测光和光谱后续观测。ZTF20abbiixp/GRB 200524A几乎没有光谱滞后，这可能源于多个重叠辐射阶段的存在，该性质在长时标暴中并不常见。该暴还显示出瞬时辐射光谱参数随强度变化的清晰演化。宽带余辉光变曲线最适合用折断幂律拟合，折断点位于GBM触发后的10^5秒处。从时变和光谱斜率计算得到的电子幂律指数（p）无法区分星际介质和星风环境。我们定制开发的余辉模型结合前向激波（FS）和反向激波（RS）辐射，能很好地拟合全波段数据，拟合早期光学数据需要RS的贡献。推断的余辉模型参数表明，ZTF20abbiixp/GRB 200524A是一个膨胀到致密星际介质（ISM）环境中的高能暴，具有较大的电子加速和磁场能量占比（ε_B）。
英文摘要
We conducted a comprehensive multi-wavelength analysis of a high energetic long-duration ZTF20abbiixp / GRB~200524A detected by \textit{Fermi} Gamma Ray Burst Monitor (GBM). Our study combines extended high-energy observations from multiple space-based observatories including \textit{Fermi} with broadband afterglow data spanning X-ray to radio wavelengths, complemented by extensive photometric and spectroscopic follow-up from several ground-based optical facilities worldwide like 3.6-m Devasthal Optical Telescope (DOT). ZTF20abbiixp / GRB~200524A exhibits almost negligible spectral lag, likely arising from the presence of multiple overlapping emission episodes, a property uncommon among long-duration bursts. The burst additionally shows a clear intensity-tracking evolution of the prompt-emission spectral parameters. The broadband afterglow light curve best fits with a broken powerlaw with a break at $10^{5}$ s since the GBM trigger. The electron powerlaw index (p) calculated from the temporal and spectral slopes fail to distinguish between a interstellar medium and a wind environment. Our custom-developed afterglow model fits the panchromatic data well, combining forward shock (FS) and reverse shock (RS) emission. The RS contribution required to fit the early time optical data. The inferred afterglow model parameters suggest that ZTF20abbiixp / GRB~200524A is a high energetic burst expanding into a dense ISM environment, with a relatively large value of the fraction of energy going to accelerating electron and magnetic field ($ε_B$).
CommentsSubmitted in MNRAS
