Trojan Stars in the Galactic Center (2008)
Fujii, Michiko, Iwasawa, Masaki, Funato, Yoko, Makino, Junichiro
We performed, for the first time, the simulation of spiral-in of a star cluster formed close to the Galactic center (GC) using a fully self-consistent N-body simulation of the system of the central...
Iwasawa, Masaki, Funato, Yoko, Makino, Junichiro
In this paper, we investigate the structures of galaxies which either have or have had three BHs using $N$-body simulations, and compare them with those of galaxies with binary BHs. We found that the...
Missing Dwarf Problem in Galaxy Clusters (2006)
Kase, Hiroyuki, Makino, Junichiro, Funato, Yoko
We investigated the formation and evolution of CDM subhalos in galaxy-sized and cluster-sized halos by means of N-body simulations. Our aim is to make clear what the ``dwarf galaxy problem'' is. It...
Three-Body Affairs in the Outer Solar System (2005)
Funato, Yoko, Makino, Junichiro, Hut, Piet, Kokubo, Eiichiro, Kinoshita, Daisuke
Recent observations (Burnes2002,Veillet2002,Margot2002a) have revealed an unexpectedly high binary fraction among the Trans-Neptunian Objects (TNOs) that populate the Kuiper Belt. The TNO binaries...
Dynamical friction on satellite galaxies (2005)
Fujii, Michiko, Funato, Yoko, Makino, Junichiro
For a rigid model satellite, Chandrasekhar's dynamical friction formula describes the orbital evolution quite accurately, when the Coulomb logarithm is chosen appropriately. However, it is not known...
Evolution of Massive Blackhole Triples I -- Equal-mass binary-single systems (2005)
Iwasawa, Masaki, Funato, Yoko, Makino, Junichiro
We present the result of $N$-body simulations of dynamical evolution of triple massive blackhole (BH) systems in galactic nuclei. We found that in most cases two of the three BHs merge through...
The formation of Kuiper-belt Binaries through Exchange Reactions (2004)
Funato, Yoko, Makino, Junichiro, Hut, Piet, Kokubo, Eiichiro, Kinoshita, Daisuke
Recent observations have revealed an unexpectedly high binary fraction among the Trans-Neptunian Objects (TNOs) that populate the Kuiper-belt. The discovered binaries have four characteristics they...
Evolution of Massive Black Hole Binaries (2003)
Makino, Junichiro, Funato, Yoko
We present the result of large-scale N-body simulations of the stellar-dynamical evolution of a massive black-hole binary at the center of a spherical galaxy. We focus on the dependence of the...
Kuiper-belt Binary Formation through Exchange Reactions (2003)
Funato, Yoko, Makino, Junichiro, Hut, Piet, Kokubo, Eiichiro, Kinoshita, Daisuke
Recent observations (Burnes et al 2002,Veillet et al 2002, Margot et al 2002a) have revealed an unexpectedly high binary fraction among the Trans-Neptunian Objects (TNOs) that populate the Kuiper...
To Circularize or Not to Circularize? -- Orbital Evolution of Satellite Galaxies (2002)
Hashimoto, Yoshikazu, Funato, Yoko, Makino, Junichiro
We investigated the orbital evolution of satellite galaxies using numerical simulations. It has been long believed that the orbit suffers circularization due to the dynamical friction from the...
Life Expectancy of the Large Magellanic Cloud (2002)
Yoko Funato, Yoshikazu Hashimoto, Junichiro Makino
We investigated the orbital evolution of sate]lite galaxies using numerical simulations. It has been long believed that the orbit suffers circularization due to the dynamical friction from the...
Missing Link Found? --- The ``runaway'' path to supermassive black holes (2001)
Ebisuzaki, Toshikazu, Makino, Junichiro, Tsuru, Takeshi Go, Funato, Yoko, Zwart, Simon Portegies, Hut, Piet, ...
Observations of stellar kinematics, gas dynamics and masers around galactic nuclei have now firmly established that many galaxies host central supermassive black holes (SMBHs) with masses in the...
A Meta-algorithm to Symmetrize Any One-step Time-integration Scheme (1999)
In this paper we present a meta-algorithm which can symmetrize any one-step timeintegration scheme. The meta-algorithm creates time symmetry, even for those algorithms which are intrinsically...
Time-Symmetrized Kustaanheimo-Stiefel Regularization (1998)
. In this paper, we show a new algorithm to integrate the orbits of binaries. Our new algorithm has the good properties of both symmetrized timesteps and KS regularization: (1) no secular error in...
On the Mass Distribution of Planetesimals in the Early Runaway Stage (1998)
Junichiro Makino, Toshiyuki Fukushige, Yoko Funato
We derive the stationary distribution of the mass of planetesimals from the coagulation equation under the assumption of energy equipartition. In the threedimensional case, we found that the...
On the Mass Distribution of Planetesimals in the Early Runaway Stage (1998)
Junichiro Makino, Toshiyuki Fukushige, Yoko Funato
We derive the stationary distribution of the mass of planetesimals from the coagulation equation under the assumption of energy equipartition. In the threedimensional case, we found that the...
On the Mass Distribution of Planetesimals in the Early Runaway Stage (1998)
Junichiro Makino, Toshiyuki Fukushige, Yoko Funato
We derive the stationary distribution of the mass of planetesimals from the coagulation equation under the assumption of energy equipartition. In the threedimensional case, we found that the...
Time Symmetrization Meta-Algorithms (1997)
Hut, Piet, Funato, Yoko, Kokubo, Eiichiro, Makino, Junichiro, McMillan, Steve
We present two types of meta-algorithm that can greatly improve the accuracy of existing algorithms for integrating the equations of motion of dynamical systems. The first meta-algorithm takes an...
Time-Symmetrized Kustaanheimo-Stiefel Regularization (1996)
Yoko Funato, Steve Mcmillan, Junichiro Makino
In this paper we describe a new algorithm for the long-term numerical integration of the two-body problem, in which two particles interact under a Newtonian gravitational potential. Although...
Time-Symmetrized Kustaanheimo-Stiefel Regularization (1996)
Yoko Funato, Steve Mcmillan, Junichiro Makino
In this paper we describe a new algorithm for the long-term numerical integration of the two-body problem, in which two particles interact under a Newtonian gravitational potential. Although...