183 citations · 4.2k across the 75 of their papers we have counts for
34 papers · 1 filter
Toward First-Principle Simulations of Galaxy Formation: II. Shock-Induced Starburst at a Collision Interface During the First Encounter of Interacting Galaxies
Takayuki R. Saitoh, Hiroshi Daisaka, Eiichiro Kokubo +5
We investigated the evolution of interacting disk galaxies using high-resolution -body/SPH simulations, taking into account the multiphase nature of the interstellar medium (ISM…
Coevolution of Supermassive Black Holes and Circumnuclear Disks
Nozomu Kawakatu, Keiichi Wada
We propose a new evolutionary model of a supermassive black hole (SMBH) and a circumnuclear disk (CND), taking into account the mass-supply from a host galaxy and the physical stat…
Toward first-principle simulations of galaxy formation: I. How should we choose star formation criteria in high-resolution simulations of disk galaxies?
Takayuki R. Saitoh, Hiroshi Daisaka, Eiichiro Kokubo +5
We performed 3-dimensional N-body/SPH simulations to study how mass resolution and other model parameters such as the star formation efficiency parameter, C* and the threshold dens…
Instabilities of Spiral Shocks -- II. A quasi-steady State in the multi-phase inhomogeneous ISM
Keiichi Wada
The ``galactic shocks'' \citep{fujimoto68,roberts69} is investigated using a full three-dimensional hydrodynamic simulations, taking into account self-gravity of the ISM, radiative…
HCN to HCO^+ Millimeter Line Diagnostics of AGN Molecular Torus I : Radiative Transfer Modeling
Masako Yamada, Keiichi Wada, Kohji Tomisaka
We explore millimeter line diagnostics of an obscuring molecular torus modeled by a hydrodynamic simulation with three-dimensional nonLTE radiative transfer calculations. Based on…
Origin of Warm High-Velocity Dense Gas in ULIRGs
Keiichi Wada
Possible origins of the molecular absorption discovered in some ULIRGs are investigated, based on a 3-D hydrodynamic model of star-forming interstellar gas in a galactic central re…
Density structure of the interstellar medium and the star formation rate in galactic disks
Keiichi Wada, Colin Norman
The probability distribution functions (PDF) of density of the ISM in galactic disks and global star formation rate are discussed. Three-dimensional hydrodynamic simulations show t…
High-Resolution Simulations of a Moon-Forming Impact and Post-Impact Evolution
Keiichi Wada, Eiichiro Kokubo, Junichiro Makino
In order to examine the ``giant impact hypothesis'' for the Moon formation, we run the first grid-based, high-resolution hydrodynamic simulations for an impact between proto-Earth…
Tidal disruption of dark matter halos around proto-globular clusters
Takayuki R. Saitoh, Jin Koda, Takashi Okamoto +2
Tidal disruption of dark matter halos around proto-globular clusters in a halo of a small galaxy is studied in the context of the hierarchical clustering scenario by using semi-cos…
Growth of Intermediate Massive Black Holes in the Hierarchical Formation of Small Spiral Galaxies in the High-z Universe
Nozomu Kawakatu, Takayuki R. Saitoh, Keiichi Wada
Combining a theoretical model of mass accretion onto a galactic center with a high-resolution -body/SPH simulation, we investigate the formation of an intermediate massive black…
Simulating Astro-E2 Observations of Galaxy Clusters: the Case of Turbulent Cores Affected by Tsunamis
Yutaka Fujita, Tomoaki Matsumoto, Keiichi Wada +1
This is the first attempt to construct detailed X-ray spectra of clusters of galaxies from the results of high-resolution hydrodynamic simulations and simulate X-ray observations i…
Molecular gas structure around an AGN with nuclear starburst: 3-D Non-LTE calculations of CO lines
Keiichi Wada, Kohji Tomisaka
We have performed three-dimensional, non-LTE radiative transfer calculations for 12CO and 13CO lines, applying them to our high-resolution hydrodynamic models of the `torus' around…
Coevolution of the galactic cores and spiral galaxies
Takayuki R. Saitoh, Keiichi Wada
Using high-resolution N-body/SPH simulations with particles, we investigate the evolution of stellar and gaseous galactic cores during the hierarchical formation of…
Comparison of Nuclear Starburst Luminosities between Seyfert 1 and 2 Galaxies Based on Near-infrared Spectroscopy
Masatoshi Imanishi, Keiichi Wada
We report on infrared K- (2-2.5 micron) and L-band (2.8-4.1 micron) slit spectroscopy of 23 Seyfert 1 galaxies in the CfA and 12 micron samples. A polycyclic aromatic hydrocarbon (…
Strong Turbulence in the Cool Cores of Galaxy Clusters: Can Tsunamis Solve the Cooling Flow Problem?
Yutaka Fujita, Tomoaki Matsumoto, Keiichi Wada
Based on high-resolution two-dimensional hydrodynamic simulations, we show that the bulk gas motions in a cluster of galaxies, which are naturally expected during the process of hi…
Tsunamis in Galaxy Clusters: Heating of Cool Cores by Acoustic Waves
Yutaka Fujita, Takeru Ken Suzuki, Keiichi Wada
Using an analytical model and numerical simulations, we show that acoustic waves generated by turbulent motion in intracluster medium effectively heat the central region of a so-ca…
Fueling Gas to the Central Region of Galaxies
Keiichi Wada
Supplying gas to the galactic central regions is one of key ingredients for AGN activity. I will review various fueling mechanisms for a R ~ 1 kpc region, determined mainly by nume…
Instabilities of Spiral Shocks I: Onset of Wiggle Instability and its Mechanism
Keiichi Wada, Jin Koda
We found that loosely wound spiral shocks in an isothermal gas disk caused by a non-axisymmetric potential are hydrodynamically unstable, if the shocks are strong enough. High reso…
Feedback From the First Supernovae in Protogalaxies:The Fate of the Generated Metals
K. Wada, A. Venkatesan
We investigate the chemo-dynamical effects of multiple supernova explosions in the central region of primordial galaxies using three-dimensional hydrodynamical simulations of the i…
Molecular Hydrogen in Damped Ly-alpha Systems: Spatial Distribution
H. Hirashita, A. Ferrara, K. Wada +1
To interpret H_2 quasar absorption line observations in Damped Ly-alpha clouds (DLAs), we model the H_2 spatial distribution within a DLA. Based on numerical simulations of disk st…
Gravity-driven Turbulence in Galactic Disks
Keiichi Wada, Gerhardt Meurer, Colin A. Norman
High-resolution, 2-D hydrodynamical simulations with a large dynamic range are performed to study the turbulent nature of the interstellar medium (ISM) in galactic disks. The simul…
Obscuring Material around Seyfert Nuclei with Starbursts
Keiichi Wada, Colin A. Norman
The structure of obscuring matter in the environment of active galactic nuclei with associated nuclear starbursts is investigated using 3-D hydrodynamical simulations. Simple analy…
Multi-Phase Gas Dynamics in a Weak Barred Potential
K. Wada, J. Koda
The structure of the interstellar medium in the central kpc region of a galaxy with a weak bar-like potential is investigated taking into account realistic cooling and heating proc…
The Three-Dimensional Structure of a Massive Gas Disk in the Galactic Central Region
Keiichi Wada
Using high-resolution, three-dimensional hydrodynamical simulations, we investigate the structure of the interstellar medium in the central hundred pc region in galaxies, taking in…