13 papers
Mass and Spin Growth of Very Massive Stars in Star Clusters Potentially Associated with Little Red Dots
Ataru Tanikawa, Masaru Shibata, Kunihito Ioka
Using gravitational -body simulations, we investigate the evolution of mass and spin for very massive stars (VMSs) in dense star clusters, which could subsequently evolve into L…
Investigating the formation channel of GW231123: Population III stars or hierarchical mergers?
Federico Angeloni, Konstantinos Kritos, Raffaella Schneider +5
The gravitational wave event GW231123, with component black hole masses lying within or above the pair-instability mass gap, poses a significant challenge to current stellar evolut…
GW231123 Formation from Population III Stars: Isolated Binary Evolution
Ataru Tanikawa, Shuai Liu, WeiWei Wu +2
GW231123 is a merger of two black holes (BHs) with estimated masses exceeding , making them the most massive BHs discovered to date via gravitational wave (GW…
Direct N-body simulations of rotating and extremely massive Population III star clusters
Kai Wu, Ataru Tanikawa, Francesco Flammini Dotti +6
Aims. We present eight direct N-body simulations with NBODY6++GPU of extremely massive, initially rotating Population III star clusters with 1.01 x 10^5 stars. Methods. Our models…
Discovery of a compact hierarchical triple main-sequence star system while searching for binary stars with compact objects
Ataru Tanikawa, Akito Tajitsu, Satoshi Honda +5
We have discovered a compact hierarchical triple main-sequence star system, which is cataloged as Gaia DR3 1010268155897156864 or TIC 21502513. Hereafter, we call it ``G1010''. G10…
Two unseen massive white dwarf candidates in close binaries
Yuta Shiraishi, Kenta Hotokezaka, Kento Masuda +10
We report the discovery of two binary systems, each consisting of a slightly bloated G-type main-sequence star and an unseen companion, identified through photometric data from TES…