6 papers
A Type Ia Supernova Candidate at : A Transient Interloper in the Search for Galaxies
Seiji Toshikage, Takahiro Morishita, Masaomi Tanaka +9
The James Webb Space Telescope (JWST) is opening a new window into the distant Universe by discovering galaxies and transients in the early Universe. We investigate a high-redshift…
GRB 260310A/SN 2026fgk: Photometric and Spectroscopic Evolution of a Nearby GRB-Supernova and an Exceptionally Bright Afterglow at z=0.153
Brendan O'Connor, Malte Busmann, Xander J. Hall +24
The association of broad-lined Type Ic supernovae with long-duration gamma-ray bursts (GRBs) has been known for 28 years. However, only about seventy gamma-ray burst supernovae (GR…
Non-LTE Ionization Modeling for Helium and Strontium in Neutron Star Merger Ejecta
Koya Chiba, Masaomi Tanaka, Shinya Wanajo +3
The material ejected from a binary neutron star merger produces "kilonova," a radioactively powered emission at ultraviolet, optical, and infrared wavelengths. The early-phase spec…
The First Search for Optical Transient as a Counterpart of a Month-timescale IceCube Neutrino Multiplet Event
Seiji Toshikage, Shigeo S. Kimura, Nobuhiro Shimizu +4
Optical transients with timescale of months, such as supernovae (SNe) and tidal disruption events (TDEs), are candidates of high-energy neutrino sources. Multiple neutrino detectio…
On the Origin of Neutron-capture Elements in r-I and r-II Stars: A Differential-abundance Analysis
Pallavi Saraf, Thirupathi Sivarani, Timothy C. Beers +4
We present a strictly line-by-line differential analysis of a moderately -process-enhanced star (-I: HD~107752) with respect to a strongly -process-enhanced star (-II:…
Systematic Investigation into Radio Supernovae with Markov Chain Monte Carlo Analysis: Implications for Massive Stars' Mass Loss and Shock Acceleration Physics
Tomoki Matsuoka, Keiichi Maeda, Shigeo S. Kimura +1
We present a systematic analysis of radio supernovae (SNe) to investigate the statistical tendencies of SN progenitors' mass-loss rates and shock acceleration efficiencies. We cond…