9 papers
Evidence of High-latitude Emission in the Prompt Phase of GRBs: How Far from the Central Engine are the GRBs Produced?
Z. Lucas Uhm, Donggeun Tak, Bing Zhang +5
One of the difficulties in nailing down the physical mechanism of gamma-ray bursts (GRBs) comes from the fact that there has been no clear observational evidence on how far from th…
Spectral Hardening Reveals Afterglow Emergence in Long-Duration Fast X-ray Transients: A Case Study of GRB 250404A/EP250404a
Yi-Han Iris Yin, Yuan Fang, Bin-Bin Zhang +56
The prompt emission and afterglow phases of gamma-ray bursts (GRBs) have been extensively studied, yet the transition between these two phases remains inadequately characterized du…
EP240414a: Off-axis View of a Jet-Cocoon System from an Expanded Progenitor Star
Jian-He Zheng, Jin-Ping Zhu, Wenbin Lu +1
When a relativistic jet is launched following the core-collapse of a star, its interaction with the stellar envelope leads to the formation of a hot cocoon, which produces various…
EP240801a/XRF 240801B: An X-ray Flash Detected by the Einstein Probe and Implications of its Multiband Afterglow
Shuai-Qing Jiang, Dong Xu, Agnes P. C. van Hoof +89
We present multiband observations and analysis of EP240801a, a low-energy, extremely soft gamma-ray burst (GRB) discovered on August 1, 2024 by the Einstein Probe (EP) satellite, w…
Isolated Black Holes as Potential PeVatrons and Ultrahigh-energy Gamma-ray Sources
Shigeo S. Kimura, Kengo Tomida, Masato I. N. Kobayashi +2
The origin of PeV cosmic rays is a long-standing mystery, and ultrahigh-energy gamma-ray observations would play a crucial role in identifying it. Recently, LHAASO reported the dis…
The Host Galaxy of the Hyperactive Repeating FRB 20240114A: Behind a Galaxy Cluster
Xiang-Lei Chen, Chao-Wei Tsai, Di Li +16
We report on the optical spectroscopic observations of the host galaxy of the hyperactive repeating fast radio burst, FRB 20240114A. The host galaxy is a dwarf galaxy at a redshift…