26 citations · 105 across the 18 of their papers we have counts for
19 papers
Testing a Pre-Supernova Contribution to Ti in Cassiopeia A
Toshiki Sato, Joshua Issa, Falk Herwig +4
The radioactive isotope Ti in Cassiopeia A has been used as a tracer of the innermost ejecta and explosion asymmetries in core-collapse supernova explosions. However, recent…
Interaction-powered Type Ibn Supernovae as a Transient PeVatron Candidate: The Case of SN 2023uqf
Ryo Sawada, Yusuke Inoue, Yosuke Ashida
We investigate whether the Type Ibn supernova SN 2023uqf, reported close in time and direction to the 442 TeV IceCube alert IC-231004A, is physically consistent with a shock-…
Impacts of hydrogen envelope on supernova fallback and the resulting compact remnant masses
Kengo Shinoda, Yudai Suwa, Ryosuke Hirai +4
Fallback in core-collapse supernovae plays a central role in setting compact-remnant masses and may produce late-time emission. In hydrogen rich progenitors, the reverse shock aris…
Cosmic-Ray Bath in a Past Supernova Gives Birth to Earth-Like Planets
Ryo Sawada, Hiroyuki Kurokawa, Yudai Suwa +3
A key question in astronomy is how ubiquitous Earth-like rocky planets are. The formation of terrestrial planets in our solar system was strongly influenced by the radioactive deca…
Inhomogeneous stellar mixing in the final hours before the Cassiopeia A supernova
Toshiki Sato, Kai Matsunaga, Hiroyuki Uchida +10
Understanding stars and their evolution is a key goal of astronomical research and has long been a focus of human interest. In recent years, theorists have paid much attention to t…
Towards Multi Energy Neutrino Astronomy: Diagnosing Enhanced Circumstellar Material around Stripped-Envelope Supernovae
Ryo Sawada, Yosuke Ashida
A novel approach is proposed to reveal a secret birth of enhanced circumstellar material (CSM) surrounding a collapsing massive star using neutrinos as a unique probe. In this sche…
Progenitor Constraint Incorporating Shell Merger: The Case of Supernova Remnant G359.0-0.9
Kai Matsunaga, Hiroyuki Uchida, Rei Enokiya +5
It is generally hard to put robust constraints on progenitor masses of supernovae (SNe) and remnants (SNRs) observationally, while they offer tantalizing clues to understanding exp…
Destratification in the Progenitor Interior of the Mg-rich Supernova Remnant N49B
Toshiki Sato, Kai Matsunaga, Ryo Sawada +6
Simulations of pre-supernova evolution suggest that some intense shell burning can be so active that, in extreme cases, it can merge with the outer shell, changing the initial cond…
Self-consistent Conditions for Al Injection into Protosolar Disk from a Nearby Supernova
Ryo Sawada, Tetsuo Taki, Hiroyuki Kurokawa +1
The early solar system contained a short-lived radionuclide, Al (its half-life time Myr). The decay energy Al is thought to have controlled the therma…
Binary Interaction Can Yield a Diversity of Circumstellar Media around Type II Supernova Progenitors
Tomoki Matsuoka, Ryo Sawada
Recent observations of supernovae (SNe) have indicated that a fraction of massive stars possess dense circumstellar medium (CSM) at the moment of their core collapses. They suggest…
Gravitational Collapse of White Dwarfs to Neutron Stars. I. From Initial Conditions to Explosions with Neutrino-radiation Hydrodynamics Simulations
Masamitsu Mori, Ryo Sawada, Yudai Suwa +3
This paper provides collapses of massive, fully convective, and non-rotating white dwarfs (WDs) formed by accretion-induced collapse or merger-induced collapse and the subsequent e…
Impacts of the reaction rate on nucleosynthesis in pair-instability supernovae
Hiroki Kawashimo, Ryo Sawada, Yudai Suwa +3
Nuclear reactions are key to our understanding of stellar evolution, particularly the rate, which is known to significantly influence the…
Updating the Ni Problem in Core-collapse Supernova Explosion
Ryo Sawada, Yudai Suwa
Details of the core-collapse supernova (CCSN) explosion mechanism still need to be fully understood. There is an increasing number of successful examples of reproducing explosions…
Constraints on Explosion Timescale of Core-Collapse Supernovae Based on Systematic Analysis of Light Curves
Sei Saito, Masaomi Tanaka, Ryo Sawada +1
Explosion mechanism of core-collapse supernovae is not fully understood yet. In this work, we give constraints on the explosion timescale based on Ni synthesized by supernov…
X-raying the Birth of Binary Neutron Stars and Neutron Star-Black Hole Binaries
Kazumi Kashiyama, Ryo Sawada, Yudai Suwa
We consider fallback accretion after an ultra-stripped supernova (USSN) that accompanies formation of a binary neutron star (BNS) or a neutron star-black hole binary (NS-BH). The f…
On the energy source of ultra-stripped supernovae
Ryo Sawada, Kazumi Kashiyama, Yudai Suwa
Ultra-stripped supernovae (USSN) with a relatively low ejecta mass of (e.g., iPTF14gqr and SN2019dge) are considered to originate from ultra-stripped carbon-oxygen…
Are stripped envelope supernovae really deficient in Ni?
Ryoma Ouchi, Keiichi Maeda, Joseph P. Anderson +1
Recent works have indicated that the Ni masses estimated for Stripped Envelope SNe (SESNe) are systematically higher than those estimated for SNe II. Although this may sugge…
A Consistent Modeling of Neutrino-driven Wind with Accretion Flow onto a Protoneutron Star and its Implications for Ni Production
Ryo Sawada, Yudai Suwa
Details of the explosion mechanism of core-collapse supernovae (CCSNe) are not yet fully understood. There is now an increasing number of successful examples of reproducing explosi…
Nucleosynthesis Constraints on the Energy Growth Timescale of a Core-collapse Supernova Explosion
Ryo Sawada, Keiichi Maeda
Details of the explosion mechanism of core-collapse supernovae (CCSNe) are not yet fully understood. There is an increasing number of numerical examples by ab-initio core-collapse…