7 papers
Temperature-resolved sensitivities of production to helium-burning reactions in pair-instability supernovae
Hiroki Kawashimo, Nobuya Nishimura, Yudai Suwa
We propose a temperature-resolved Monte Carlo (MC) approach to identify the temperature regimes in which low-energy helium-burning reaction rates most strongly affect nucleosynthes…
Evidence of Nuclear Urca Process in the Ocean of Neutron-Star Superburst MAXI J1752457
Hao Huang, Akira Dohi, Amira Aoyama +2
We propose that the rapid cooling of the neutron star following its X-ray superburst in MAXI J1752457 over a period of 4 days, observed by two Japanese satellites, MAXI and Ninj…
Return of the Clocked Burster: Exceptionally Short Recurrence Time in GS 1826-238
Tomoshi Takeda, Toru Tamagawa, Teruaki Enoto +15
We report the discovery of an exceptionally short burst recurrence time in the well-known clocked burster GS 1826238, observed with the CubeSat X-ray observatory NinjaSat. In 20…
Thermonuclear superburst of MAXI J1752457 observed with NinjaSat and MAXI
Amira Aoyama, Teruaki Enoto, Takuya Takahashi +17
An uncatalogued bright X-ray transient was detected with MAXI on November 9, 2024, named MAXI J1752457. The NinjaSat X-ray observatory promptly observed the source from November…
Systematic study of the composition of Type I X-ray burst ashes: Neutron star structure v.s. Reaction rate uncertainties
Guoqing Zhen, Helei Liu, Akira Dohi +4
In this study, we calculate for the first time the impacts of neutron star(NS) structure on the type I X-ray burst ashes using the \texttt{MESA} code. We find an increased mass fra…
NinjaSat monitoring of Type-I X-ray bursts from the clocked burster SRGA J144459.2604207
Tomoshi Takeda, Toru Tamagawa, Teruaki Enoto +25
The CubeSat X-ray observatory NinjaSat was launched on 2023 November 11 and has provided opportunities for agile and flexible monitoring of bright X-ray sources. On 2024 February 2…