activity
20242026
collaborators

5 papers

astro-ph.HE2026

Revisiting early afterglows of gamma-ray bursts with finite-thickness ejecta: Implications from XRF 080330 and GRB 080710

Kaori Obayashi, Ryo Yamazaki, Yo Kusafuka +1

We revisit the physical origin of the achromatic peaks and breaks observed several thousand seconds after the burst in the multi-wavelength afterglows of XRF 080330 and GRB 080710.…

astro-ph.HE2026

Unifying Circumstellar Environment in Broad-Lined Type Ic Radio Supernovae Towards Off-axis Gamma-Ray Burst Exploration

Yo Kusafuka, Tomoki Matsuoka, Ryo Sawada

Decades have passed since the first confirmed association between a broad-lined Type Ic supernova (Type IcBL SN) and a long gamma-ray burst (GRB), and the number of known GRB-SN as…

astro-ph.HE2025

Double-Peaked Optical Afterglow in GRB 110213A Inferring a Magnetized Thick Shell Ejecta

Yo Kusafuka, Kaori Obayashi, Katsuaki Asano +1

Gamma-ray bursts early afterglows are important tracers for determining the radial structure and magnetization of the ejecta. In this paper, we focus on GRB 110213A that shows doub…

astro-ph.HE2025

TeV Afterglow of BOAT GRB without Jet Break

Yo Kusafuka, Katsuaki Asano

We present a new model for the TeV afterglow of GRB 221009A. The rapid increase of the TeV flux in the very early phase is reproduced by the magnetic acceleration. We consider the…

astro-ph.HE2024

Ejecta Width and Magnetization Reflected in Gamma-Ray Burst Early Afterglows: Implication for Reverse Shock Component and Shallow Decay Phase

Yo Kusafuka, Katsuaki Asano

To study the ejecta property dependence of the gamma-ray burst (GRB) afterglow, we carry out spherically symmetrical one-dimensional special relativistic magneto-hydrodynamic simul…