A5004848222- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Cosmology and Gravitation Theories
- Stellar, planetary, and galactic studies
- Scientific Research and Discoveries
- Astrophysics and Star Formation Studies
- Astro and Planetary Science
- Dark Matter and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Astrophysics and Cosmic Phenomena
- Radio Astronomy Observations and Technology
- Geophysics and Gravity Measurements
- Solar and Space Plasma Dynamics
- Geology and Paleoclimatology Research
- History and Developments in Astronomy
- Astronomical Observations and Instrumentation
- Relativity and Gravitational Theory
- Methane Hydrates and Related Phenomena
- Pulsars and Gravitational Waves Research
- Cardiac Structural Anomalies and Repair
- Remote Sensing in Agriculture
- Advanced Thermodynamics and Statistical Mechanics
- Adaptive optics and wavefront sensing
- Advanced Mathematical Theories and Applications
The University of Tokyo
2015-2024
Kochi University of Technology
2022-2024
Ibaraki University
1990-2021
Kavli Institute for the Physics and Mathematics of the Universe
2020
Fuji Heavy Industries Health Insurance Society Ota Memorial Hospital
2018
Science Council of Japan
2016-2017
National Astronomical Observatory of Japan
2001-2016
Nagoya University
2007-2015
Princeton University
2010-2015
Yokohama National University
2014
We study the luminosity and color dependence of galaxy two-point correlation function in Sloan Digital Sky Survey, starting from a sample ~200,000 galaxies over 2500 deg2. concentrate our analysis on volume-limited subsamples specified ranges, for which we measure projected wp(rp), is directly related to real-space ξ(r). The amplitude wp(rp) rises continuously with Mr ≈ -17.5 -22.5, most rapid increase occurring above characteristic L* (Mr -20.5). Over scales 0.1 h-1 Mpc < rp 10 Mpc,...
We present a detailed nonspherical modeling of dark matter halos on the basis combined analysis high-resolution halo simulations (12 with N ~ 106 particles within their virial radius) and large cosmological (five realizations = 5123 in 100 h-1 Mpc box size). The density profiles those simulated are well approximated by sequence concentric triaxial distribution axis directions being fairly aligned. characterize model quantitatively generalizing universal profile, that has previously been...
This paper presents the second data release of Hyper Suprime-Cam Subaru Strategic Program, a wide-field optical imaging survey on 8.2 meter Telescope. The includes from 174 nights observation through January 2018. Wide layer cover about 300 deg^2 in all five broadband filters (grizy) to nominal exposure (10min gr and 20min izy). Partially observed areas are also included release; 1100 is at least one filter exposure. median seeing i-band 0.6 arcsec, demonstrating superb image quality survey....
Abstract The Subaru Prime Focus Spectrograph (PFS) is a massively multiplexed fiber-fed optical and near-infrared three-arm spectrograph (Nfiber = 2400, 380 ≤ λ 1260 nm, 1 $_{.}^{\circ}$3 diameter field of view). Here, we summarize the science cases in terms provisional plans for 300-night survey. We describe to constrain nature dark energy via survey emission line galaxies spanning comoving volume 9.3 h−3 Gpc3 redshift range 0.8 &lt; z 2.4. In each six bins, cosmological distances will...
The Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) is a three-layered imaging survey aimed at addressing some of the most outstanding questions in astronomy today, including nature dark matter and energy. has been awarded 300 nights observing time Telescope it started March 2014. This paper presents first public data release HSC-SSP. includes taken 1.7 years observations (61.5 nights) each Wide, Deep, UltraDeep layers covers about 108, 26, 4 square degrees down to depths i~26.4, ~26.5,...
Abstract This paper presents the third data release of Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP), a wide-field multi-band imaging survey with 8.2 m telescope. HSC-SSP has three layers (Wide, Deep, and UltraDeep) different area coverages depths, designed to address wide array astrophysical questions. from includes 278 nights observing time covers about 670 deg2 in all five broad-band filters (grizy) at full depth (∼26 mag 5σ depending on filter) Wide layer. If we include partially...
We perform a series of high-resolution N-body simulations designed to examine the density profiles dark matter halos. From 12 simulated halos ranging in mass from 2x1012 5x1014 h-1 M middle dot circle (represented by approximately 1 million particles within virial radius), we find clear systematic correlation between halo and slope profile at 1% radius, addition variations among similar mass. More specifically, is -1.5, -1.3, -1.1 for galaxy-, group-, cluster-mass halos, respectively. While...
We determine the stellar, planetary, and orbital properties of transiting planetary system HD 209458 through a joint analysis high-precision radial velocities, photometry, timing secondary eclipse. Of primary interest is strong detection Rossiter-McLaughlin effect, alteration photospheric line profiles that occurs because planet occults part rotating surface star. develop new technique for modeling this effect use it to inclination orbit relative apparent stellar equator (λ = -4.°4 ± 1.°4),...
A transiting extrasolar planet sequentially blocks off the light coming from different parts of disk host star in a time dependent manner. Due to spin star, this produces an asymmetric distortion line profiles stellar spectrum, leading apparent anomaly radial velocity curves, known as Rossiter - McLaughlin effect. Here, we derive approximate but accurate analytic formulae for curves taking account limb darkening. The are particularly useful extracting information projected angle between...
view Abstract Citations (282) References (35) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Semianalytic Predictions for Statistical Properties of X-Ray Clusters Galaxies in Cold Dark Matter Universes Kitayama, Tetsu ; Suto, Yasushi Temperature and luminosity functions X-ray clusters are computed semianalytically, combining a simple model the cluster gas properties with distribution halo formation epochs proposed by Lacey & Cole Kitayama Suto. In contrast...
We examine the age-dependence of dark matter halo clustering in an unprecedented accuracy using a set 7 high-resolution cosmological simulations each with $N=1024^3$ particles. measure bias parameters for halos over large mass range cross-power-spectrum method that can effectively suppress random noise even sparse sampling most massive halos. This enables us to find, first time, younger are more strongly clustered than older ones masses $M>10M_{\ast}$, where $M_\ast$ is characteristic...
PFS (Prime Focus Spectrograph), a next generation facility instrument on the 8.2-meter Subaru Telescope, is very wide-field, massively multiplexed, optical and near-infrared spectrograph. Exploiting prime focus, 2394 reconfigurable fibers will be distributed over 1.3 deg field of view. The spectrograph has been designed with 3 arms blue, red, cameras to simultaneously observe spectra from 380nm 1260nm in one exposure at resolution ~1.6-2.7A. An international collaboration developing this...
The X-ray cluster gas density distribution in hydrostatic equilibrium is computed from the universal profile of dark matter halo proposed by Navarro, Frenk, & White two recent studies. If one assumes isothermality, resulting well approximated conventional β-model. We predict core radius rc, β-parameter, and luminosity clusters as a function temperature TX some representative cosmological models compare them with observations results numerical simulations. predicted size rc factor 3-10...
Equations of self-gravitating systems in the Universe are solved by expanding as perturbation series Fourier space. The formulas for higher-order terms given density and velocity fields. We apply to several analytically integrable models whose linear power spectra obey a single law, asymptotically approach prediction cold-dark-matter scenario. explicitly give nonlinear gravitational evolution fields its dependence on initial spectrum.
We present photometry of HD 189733 during eight transits its close-in giant planet, and out-of-transit spanning 2 yr. Using the transit photometry, we determine stellar planetary radii photometric ephemeris. Outside transits, there are quasi-periodic flux variations with a 13.4 day period that attribute to rotation. In combination previous results, derive upper limits on orbital eccentricity true angle between rotation axis orbit (as opposed projections those axes sky).
We quantitatively study the probability distribution function (PDF) of cosmological nonlinear density fluctuations from N-body simulations with Gaussian initial condition. In particular, we examine validity and limitations one-point two-point log-normal PDF models against those directly estimated simulations. find that describes very accurately even in regime (the rms variance σ_{nl} \simlt 4 over-density δ\simlt 100). Furthermore PDFs are also good agreement simulation data linear to fairly...
We measure the topology of volume-limited galaxy samples selected from a parent sample 314,050 galaxies in Sloan Digital Sky Survey(SDSS), which is now complete enough to describe fully three-dimensional and its dependence on properties. compare observed genus statistic G\nu_f) predictions for Gaussian random field measured mock surveys constructed new large-volume simulations LambdaCDM cosmology. In this analysis we carefully examine smoothing scale R_G 3.5 11 h^-1Mpc luminosity over range...
Abstract We report a measurement of the Rossiter–McLaughlin effect in transiting extrasolar planetary system TrES-1, via simultaneous spectroscopic and photometric observations with Subaru MAGNUM telescopes. By modeling radial velocity anomaly that was observed during transit, we determine sky-projected angle between stellar spin axis orbital to be $\lambda = 30^{\circ}\pm 21^{\circ}$. This is third case for which $\lambda$ has been measured exoplanetary system, first demonstration such...
Characterizing the surfaces of rocky exoplanets via their scattered light will be an essential challenge in investigating habitability and possible existence life on surfaces. We present a reconstruction method for fractional areas different surface types from colors Earth-like exoplanet. create mock curves Earth without clouds using empirical data. These are fitted to isotropic scattering model consisting four types: ocean, soil, snow, vegetation. In idealized situation where photometric...
We obtain analytical expressions for the velocity anomaly due to Rossiter- McLaughlin effect, case when anomalous radial is obtained by cross-correlation with a stellar template spectrum. In limit of vanishing width absorption lines, our result reduces formula derived Ohta et al. (2005), which based on first moment distorted lines. Our new contains term dependent linewidth, becomes important rotational line broadening appreciable. generate mock transit spectra four existing exoplanetary...
We use a series of cosmological N-body simulations and various analytic models to study the evolution matter power spectrum in real space ΛCold Dark Matter universe. compare results against three analytical model predictions; standard perturbation theory, renormalized closure approximation. include effects from finite simulation box size comparison. determine values maximum wavenumbers, k^{lim}_{1%} k^{lim}_{3%}, below which agree within 1 3 percent, respectively. then provide simple...
We present an investigation of spin-orbit angles for planetary system candidates reported by Kepler. By combining the rotational period $P_s$ inferred from flux variation due to starspots and projected velocity $V\sin I_s$ stellar radius obtained a high resolution spectroscopy, we attempt estimate inclination $I_s$ spin axis with respect line-of-sight. For transiting systems, in which orbits are edge-on seen us, can be useful indicator alignment/misalignment. newly conducted spectroscopic...
We present photometric and spectroscopic observations of the 2009 February 2 transit exoplanet XO-3b. The new data show that planetary orbital axis stellar rotation are misaligned, as reported earlier by Hébrard coworkers. find angle between sky projections two axes to be 37.3 ± 3.7 deg, compared previously value 70 15 deg. significance this discrepancy is unclear because there indications systematic effects. XO-3b first known have a highly inclined orbit relative equatorial plane its parent...
We present an improved formula for the anomalous radial velocity of star during planetary transits due to Rossiter-McLaughlin (RM) effect. The improvement comes from a more realistic description stellar absorption line profiles, taking into account rotation, macroturbulence, thermal broadening, pressure and instrumental broadening. Although is derived case in which velocities are measured by cross-correlation, we show through numerical simulations that accurately describes cases where with...