The gamma-ray burst (GRB) jet powers the afterglow emission by shocking the surrounding medium, and radio afterglow can now be routinely observed to almost a year after the explosion. Long-duration GRBs are accompanied by supernovae (SNe) that typically contain much more energy than the GRB jet. Here we consider the fact that the SN blast wave will also produce its own afterglow (supernova remnant emission), which will peak at much later time (since it is non-relativistic), when the SN blast wave transitions from a coasting phase to a decelerating Sedov-Taylor phase. We predict that this component will peak generally a few tens of years after the explosion and it will outshine the GRB powered afterglow well-before its peak emission. In the case of GRB 030329, where the external density is constrained by the $\sim 10$-year coverage of the radio GRB afterglow, the radio emission is predicted to start rising over the next decade and to continue to increase for the following decades up to a level of $\sim$ mJy. Detection of the SN-powered radio emission will greatly advance our knowledge of particle acceleration in $ \sim 0.1$c shocks.
The origin of the plateau and late rebrightening in the afterglow of GRB 120326A
GRB 120326 A是一个不寻常的伽马射线暴，它在X射线波段和光学波段都有一个相当长的平台和一个非常晚的再亮。光学和X射线光变曲线的相似行为表明它们可能有共同的起源。漫长的平台期从几百秒开始，到几万秒结束。后期再亮的峰值时间约为30000s。我们分析了能量注入模型的数值和解析解，考虑风环境和ISM环境的伽玛暴余辉。我们特别研究了注入开始时间、结束时间、星风密度（或环暴环境密度）和注入光度对余辉光变曲线形状的影响。我们发现，光变曲线在很大程度上受风模型中的参数。只有在风模型中，在后期也有一个“颠簸”。在风的情况下，有趣的是，能量注入的时间越长，再亮就越明显。我们还发现碰撞的峰值时间与星风密度有关。我们用晚期连续注入模型解释了GRB 120326A的异常余辉。该模型能很好地拟合观测数据，但我们发现，注入的时间尺度必须大于一万秒。这意味着中央引擎活动的时间尺度必须超过一万秒。这可以对伽玛暴的中心引擎提供有用的约束。我们考虑一颗新诞生的毫秒脉冲星，它具有强磁场作为中心引擎。另一方面，我们的研究结果表明，GRB 120326A的环暴环境很可能是恒星风。
We study the broadband radiation behavior of a kilonova ejecta-pulsar wind nebula (PWN) system. In this model, we jointly fit the observations of AT 2017gfo in UV-optical-IR bands and the late-time X-ray afterglow of GRB 170817A. Our work shows that a PWN powered by the remnant neutron star (NS) post GW170817 event could affect the optical transient AT 2017gfo and re-brighten the late-time X-ray afterglow of GRB 170817A. The PWN radiation will regulate the trend of future X-ray observations from a flattening to a steep decline until some other sources (e.g., a kilonova afterglow) become domina…
Long gamma-ray bursts give us the chance to study both their extreme physics and the star-forming galaxies in which they form. GRB 100418A, at a z = 0.6239, had a bright optical and radio afterglow, and a luminous star-forming host galaxy. This allowed us to study the radiation of the explosion as well as the interstellar medium of the host both in absorption and emission. We collected photometric data from radio to X-ray wavelengths to study the evolution of the afterglow and the contribution of a possible supernova and three X-shooter spectra obtained during the first 60 hr. The light curve …
We present a search for late-time rebrightening of radio emission from three supernovae (SNe) with associated gamma-ray bursts (GRBs). It has been previously proposed that the unusually energetic SNe associated with GRBs should enter the Sedov-Taylor phase decades after the stellar explosion, and this SN "remnant" emission will outshine the GRB radio afterglow and be detectable at significant distances. We place deep limits on the radio luminosity of GRB 980425/SN 1998bw, GRB 030329/SN 2003dh and GRB 060218/SN 2006aj, 10-18 years after explosion, with our deepest limit being $L_ν$ $< 4 \times …
Multi-epoch afterglow rebrightenings in GRB 250129A: Evidence for successive shock interactions
Université de la Côte d’Azur（蔚蓝海岸大学）；New York University Abu Dhabi（阿布扎比纽约大学）；Center for Astrophysics and Space Science (CASS), New York University Abu Dhabi（阿布扎比纽约大学天体物理学与空间科学中心）；IJCLab, Univ Paris-Saclay, CNRS/IN2P3（巴黎萨克雷大学IJCLab实验室）；Institute of Physics and Astronomy, Theoretical Astrophysics, University Potsdam（波茨坦大学物理与天文学研究所理论天体物理系）；Nikhef（尼赫夫国家粒子物理研究所）；Institute for Gravitational and Subatomic Physics (GRASP), Utrecht University（乌得勒支大学引力与亚原子物理研究所）；Purple Mountain Observatory, Chinese Academy of Sciences（中国科学院紫金山天文台）；Instituto de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México（墨西哥国立自治大学射电天文学与天体物理研究所）；Physics Department, Nazarbayev University（纳扎尔巴耶夫大学物理系）；Energetic Cosmos Laboratory, Nazarbayev University（纳扎尔巴耶夫大学高能宇宙实验室）；Université Paris-Saclay, Université Paris Cité, CEA, CNRS, AIM（巴黎萨克雷大学、巴黎西岱大学、法国原子能与替代能源委员会、法国国家科学研究中心）；E.Kharadze Georgian National Astrophysical Observatory（E.哈拉泽格鲁吉亚国家天文台）
GRB 250129A表现出多个晚期时间X射线和光学波段的再变亮现象，研究通过分析促发辐射和近红外数据，揭示后光再变亮可能由延迟碰撞刷新冲击波引起。
Short-duration GRB 250221A Afterglow Driven by Two-Component Jets from the merger of a compact star
Guangxi University（广西大学）；Nanjing University（南京大学）；Purple Mountain Observatory, Chinese Academy of Sciences（中国科学院紫金山天文台）；University of Science and Technology of China（中国科学技术大学）
GRB 250221A的后glow由双组分喷流模型解释，揭示了短持续时间GRB的双喷流机制及周际介质密度特征。
We performed calculations of the late radio and X-ray afterglow of GRB/GW170817 in the cocoon-jet paradigm, predicting the appearance of a second peak in the afterglow light curve ~ one-three years after the explosion. The model assumes that the prompt emission and early afterglows originate from a cocoon generated during break-out of the delayed magnetically powered jet. As the jet breaks out from the torus-generated wind, a nearly isotropic mildly relativistic outflow is generated; at the same time the primary jet accelerates to high Lorentz factors and avoids detection. As the fast jet slow…
VLBI and Archival VLA and WSRT Observations of the GRB 030329 Radio Afterglow
我们介绍VLBI和档案卡尔G。Jansky甚大阵列（VLA）和Westerbork综合射电望远镜（WSRT）对2003年3月29日伽马射线暴（GRB 030329）的射电余辉的观测，在爆发后672至2032天之间进行。EVLA和WSRT的数据表明，在5 GHz的通量简单的幂律衰减，没有任何明显的迹象，从反喷流的再亮。我们报告了一个未解决的来源，在2032天的大小$1.18\pm0.13$ mas，我们使用结合膨胀率的爆发，认为存在一个统一的，ISM样环爆介质。我们发展了一种半解析的方法来模拟伽马射线暴的余辉，并将其应用到5 GHz的光变曲线进行爆发量热。自行受到$< 0.067$ mas yr $^{-1}$的限制，支持伽马射线暴的标准余辉模型。
Afterglows of Gamma-Ray Bursts (GRBs) are simple in the most basic model, but can show many complex features. The ultra-long duration GRB 111209A, one of the longest GRBs ever detected, also has the best-monitored afterglow in this rare class of GRBs. We want to address the question whether GRB 111209A was a special event beyond its extreme duration alone, and whether it is a classical GRB or another kind of high-energy transient. The afterglow may yield significant clues. We present afterglow photometry obtained in seven bands with the GROND imager as well as in further seven bands with the U…
An extremely bright slow-rising afterglow from an off-axis jet in GRB 260310A
University of Rome “Tor Vergata”（罗马第二大学）；INAF - Istituto di Radioastronomia（意大利国家天体物理研究所射电天文台）；The Hong Kong Institute for Astronomy and Astrophysics, The University of Hong Kong（香港大学香港天文及天体物理研究所）；Department of Physics, The University of Hong Kong（香港大学物理系）；Instituto de Astrofísica de Andalucía (IAA-CSIC)（安达卢西亚天体物理学研究所（西班牙高等科学研究委员会））；McWilliams Center for Cosmology and Astrophysics, Department of Physics, Carnegie Mellon University（卡内基梅隆大学麦威廉斯宇宙学与天体物理学中心物理系）
Gamma-ray bursts (GRBs) at high redshifts are expected to be gravitationally lensed by objects of different mass scales. Besides a single recent claim, no lensed GRB has been detected so far by using the gamma-ray data only. In this paper, we suggest that the multi-band afterglow data might be an efficient way to search for lensed GRB events. Using the standard afterglow model we calculate the characteristics of the lensed afterglow lightcurves under the assumption of two popular analytic lens models: point mass and Singular Isothermal Sphere (SIS) model. In particular, when different lensed i…
The broadband afterglow of GW170817/GRB 170817A is believed to be from an off-axis structured jet. The central engine of a gamma-ray burst usually launches a pair of outflows that move oppositely, it is reasonable to consider the emission from a double-sided structured jets, with a near-jet moving toward us and a counter-jet moving away from us. Assuming that the two branches of the jet have the same physical parameters, we have calculated their radio emission. It is found that the counter-jet component will emerge in the radio light curves $\sim$ 2500 days post-merger.It typically leads to a …
The long gamma-ray burst GRB 161017A was detected by Fermi and Swift, and its afterglow was observed by the MITSuME 50-cm optical telescope promptly about 50 s after the burst. Early optical observations revealed that the optical lightcurve exhibits a plateau and rebrightening in the early afterglow phase about 500 and 5000 s after the trigger, respectively. By investigating the behavior of the spectral and temporal flux variation, it was found that the plateau and re-brightening cannot be explained in the context of the simple standard afterglow model. These observational features can be expl…
A Shell Collision Scenario for EP251222b/GRB 251222A: Connecting Prompt Emission and Double-Peaked Afterglow
Purple Mountain Observatory, Chinese Academy of Sciences（中国科学院紫金山天文台）；School of Astronomy and Space Sciences, University of Science and Technology of China（中国科学技术大学天文与空间科学学院）；State Key Laboratory of Radio Astronomy and Technology, Purple Mountain Observatory, Chinese Academy of Sciences（中国科学院紫金山天文台射电天文与技术重点实验室）；South-Western Institute for Astronomy Research, Yunnan University（云南大学西南天文研究所）；Yunnan Key Laboratory of Survey Science, Yunnan University（云南大学云南省测绘科学重点实验室）
We present the results of a detailed investigation of the prompt and afterglow emission in the HESS detected GRB 190829A. Swift and Fermi observations of the prompt phase of this GRB reveal two isolated sub-bursts or episodes, separated by a quiescent phase. The energetic and the spectral properties of the first episode are in stark contrast to the second. The first episode, which has a higher spectral peak of $\sim 120\:\text{keV}$ and a low isotropic energy $\sim 10^{50}\:\text{erg}$ is an outlier to the Amati correlation and marginally satisfies the Yonetoku correlation. However, the energe…
IGR J12580+0134: A Possible Repeated Partial Tidal Disruption Event Inferred from Late-Time Radio Re-brightenin
Huazhong University of Science and Technology（华中科技大学）；Shanghai Astronomical Observatory, Chinese Academy of Sciences（中国科学院上海天文台）；Purple Mountain Observatory, Chinese Academy of Sciences（中国科学院紫金山天文台）；University of Science and Technology of China（中国科学技术大学）
Given an increasing number of gamma-ray bursts accompanied by potential kilonovae there is a growing importance to advance modelling of kilonova afterglows. In this work, we investigate how the presence of two electron populations that follow a Maxwellian (thermal) and a power-law (non-thermal) distributions affect kilonova afterglow light curves. We employ semi-analytic afterglow model, $\texttt{PyBlastAfterglow}$. We consider kilonova ejecta profiles from ab-initio numerical relativity binary neutron star merger simulations, targeted to GW170817. We do not perform model selection. We find th…
The diversity of progenitors and emission mechanisms for ultra-long bursts
GRB 111209 A是有记录以来最长的爆发。这次爆发被Swift和Konus-Wind探测到，我们从XMM-Newton获得了TOO时间，并从TAROT获得了即时数据。我们使用这些仪器和其他仪器的数据进行了共同的减少。这使得第一次精确的研究在高信噪比的提示余辉过渡。我们发现，有几种机制负责这一阶段。在其提示阶段，我们表明，其持续时间超过20 000秒。这一点，再加上爆发通量是其他事件中观察到的前5%的事实，使得这个事件非常活跃。我们讨论了可能的祖先，可以解释极端的持续时间属性，这个爆发，以及它的光谱特性。我们目前的证据表明，这种爆发属于一个新的，以前未确定的，一类伽玛射线暴。这类恒星最可能的祖先是一颗低金属量的蓝超巨星。我们表明，选择效应可以防止检测到其他爆炸在较大的红移，并得出结论，这种事件是内在罕见的本地宇宙。余辉呈现出与其他正常长伽玛暴相似的特征，并且在光学波长上呈现出与其他长伽玛暴相似的后期再亮现象。从无线电到X射线的宽带SED在晚些时候并没有显示出与预期的标准火球余辉同步辐射的显着偏差。
The physical origin of optical flares following GRB 110205A and the nature of the outflow
GRB 110205A的光辐射由两个耀斑区分。在这项工作中，我们研究了两种可能的情况下的光学余辉发射。在第一种情况下，第一个光学耀斑是主外流的反向激波发射，第二个是由中央发动机的长期活动提供动力。然而，我们发现，除非伽玛暴效率很高（$\sim 0.95$），否则很难合理地解释后期（$t>0.1$日）的余辉数据。在第二种情况下，第一个光学耀斑是低能瞬发辐射，第二个是初始外流的反向激波。在这种情况下，我们可以解释晚余辉发射自洽。反激波区可能是弱磁化的，第二次光学耀斑的衰减可能是由高纬发射主导的，这可能是伴随着快速衰减的强偏振演化，如Fan等人在2008年提出的。RINGO 2型旋光仪的时间分辨旋光将直接检验我们的预测。
GRB 260310A / SN 2026fgk: A Multi-Wavelength Study of a Nearby Underluminous Long GRB and SN with a Complex Afterglow
Instituto de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México（墨西哥国立自治大学射电天文学与天体物理研究所）；Astrophysics Research Center of the Open university (ARCO), The Open University of Israel（以色列开放大学天体物理学研究中心）；Instituto de Astronomía, Universidad Nacional Autónoma de México（墨西哥国立自治大学天文研究所）；Aix Marseille Univ., CNRS, CNES, LAM, Marseille, France（法国马赛艾克斯-马赛大学）；E. Kharadze Georgian National Astrophysical Observatory（格鲁吉亚国家天体物理观测站）；Aix Marseille University, CNRS, CPPM, Marseille, France（法国马赛艾克斯-马赛大学）；Department of Space Science, University of Alabama in Hun（阿拉巴马大学空间科学系）
EP250302a: violent shell collision in a soft-X-ray-selected GRB-like transient
Huazhong University of Science and Technology（华中科技大学）；Nanjing University（南京大学）；Institute of High Energy Physics, Chinese Academy of Sciences（中国科学院高能物理研究所）；Yunnan Observatories, Chinese Academy of Sciences（中国科学院云南天文台）；National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；Shanghai Astronomical Observatory, Chinese Academy of Sciences（中国科学院上海天文台）
