activity
20242026
collaborators

7 papers

astro-ph.HE2026

SN 2024dy: Dust formation in a long-lived Type IIn supernova and constraints on the dust mass

Sota Goto, Masayuki Yamanaka, Koji S. Kawabata +10

Type~IIn supernovae (SNe) are a subclass of core-collapse SNe powered by interaction between the ejecta and the dense circumstellar material. Among them, long-lived Type~IIn events…

astro-ph.HE2026

Ultraviolet Signatures of Jet-Ejecta Interaction in Early Kilonovae: Prediction from Realistic Atomic Opacities

Smaranika Banerjee, Hamid Hamidani, Kyohei Kawaguchi +1

We investigate the signature of the jet-ejecta interaction in early kilonova (t < 1day) using detailed atomic opacities developed in Banerjee et al. (2020, 2024), appropriate for e…

astro-ph.HE2025

EP240414a: A Gamma-Ray Burst Jet Weakened by an Extended Circumstellar Material

Hamid Hamidani, Yuri Sato, Kazumi Kashiyama +3

The recent Einstein Probe (EP) event EP240414a exhibits several unusual observational features. Its prompt and afterglow emissions place it between long gamma-ray bursts (LGRBs) an…

astro-ph.HE2025

Gamma-Ray Burst Jets in Circumstellar Material: Dynamics, Breakout, and Diversity of Transients

Hamid Hamidani, Kunihito Ioka, Kazumi Kashiyama +1

Recent observations indicate that stripped-envelope core-collapse supernovae are often surrounded by dense circumstellar material (CSM). Motivated by this, we develop an analytic m…

astro-ph.HE2025

Linking Analytic Light Curve Models to Physical Properties of Kilonovae

Ayari Kitamura, Kyohei Kawaguchi, Masaomi Tanaka +1

In binary neutron star mergers, lanthanide-rich dynamical ejecta and lanthanide-poor post-merger ejecta have been often linked to the red and blue kilonova emission, respectively.…

astro-ph.HE2025

SN 2021foa: the bridge between SN IIn and Ibn

Anjasha Gangopadhyay, Naveen Dukiya, Takashi J Moriya +26

We present the long-term photometric and spectroscopic analysis of a transitioning SN~IIn/Ibn from 10.8 d to 150.7 d post -band maximum. SN~2021foa shows prominent He {\sc i}…