A5107791933- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Adaptive optics and wavefront sensing
- Stellar, planetary, and galactic studies
- Astronomical Observations and Instrumentation
- Radio Astronomy Observations and Technology
- Particle Accelerators and Free-Electron Lasers
- Astrophysical Phenomena and Observations
- Gamma-ray bursts and supernovae
- Astrophysics and Star Formation Studies
- History and Developments in Astronomy
- Semiconductor Lasers and Optical Devices
- Photocathodes and Microchannel Plates
- Optical Coatings and Gratings
- Photorefractive and Nonlinear Optics
- Photonic and Optical Devices
- Distributed and Parallel Computing Systems
- solar cell performance optimization
- Advanced Fluorescence Microscopy Techniques
- Impact of Light on Environment and Health
- Astrophysics and Cosmic Phenomena
- Black Holes and Theoretical Physics
- Atmospheric Ozone and Climate
- Scientific Research and Discoveries
- Cosmology and Gravitation Theories
The University of Tokyo
2012-2025
Kavli Institute for the Physics and Mathematics of the Universe
2011-2025
National Astronomical Observatory of Japan
2006-2025
National Institutes of Natural Sciences
2013
Subaru (Japan)
2006-2012
National Defense Academy of Japan
2010
Las Cumbres Observatory Global Telescope Network
2008
Canada–France–Hawaii Telescope
2003-2008
Durham University
2003-2006
Kyoto University
1998-2003
We measure the redshift-space correlation function from a spectroscopic sample of 2783 emission line galaxies FastSound survey. The survey, which uses Subaru Telescope and covers redshift ranges $1.19<z<1.55$, is first cosmological study at such high redshifts. detect clear anisotropy due to distortions (RSD) both in as separations parallel perpendicular sight its quadrupole moment. RSD has been extensively used test general relativity on scales $z<1$. Adopting LCDM cosmology with fixed...
We present the most extensive combined photometric and spectroscopic study to date of enormous globular cluster (GC) system around M87, central giant elliptical galaxy in nearby Virgo cluster. Using observations from DEIMOS LRIS at Keck, Hectospec on MMT, we derive new, precise radial velocities for 451 GCs with projected radii ~ 5 185 kpc. combine these measurements literature data a total sample 737 objects, which use re-examination kinematics GC M87. The are analyzed context archival...
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...
We present near-infrared spectroscopic observations of star-forming galaxies at z~1.4 with FMOS on the Subaru Telescope. observed K-band selected in SXDS/UDS fields K<23.9 mag, 1.2<z_ph<1.6, M*>10^{9.5} Msun, and expected F(Halpha)>10^{-16} erg s^{-1} cm^{-2}. 71 objects sample have significant detections Halpha. For these objects, excluding possible AGNs identified from BPT diagram, gas-phase metallicities are obtained [NII]/Halpha line ratio. The is split into three stellar mass bins,...
Fibre Multi-Object Spectrograph (FMOS) is the first near-infrared instrument with a wide field of view capable acquiring spectra simultaneously from up to 400 objects. It has been developed as common-use for F$/$2 prime-focus Subaru Telescope. The coverage 30$^\prime$ diameter achieved using new 3-element corrector optimized in (0.9–1.8$\ \mu$m) wavelength range. Due limited space at prime-focus, we have had develop novel fibre positioner, called “Echidna”, together two OH-airglow suppressed...
We present a stellar mass–metallicity relation at z ∼ 1.4 with an unprecedentedly large sample of ∼340 star-forming galaxies obtained Fibre Multi-Object Spectrograph (FMOS) on the Subaru Telescope. observed K-band selected 1.2 ≤ zph 1.6 in XMM–Newton Deep Survey/Ultra Survey fields M* ≥ 109.5 M⊙, and expected F(Hα) 5 × 10−17 erg s−1 cm−2. Among ∼1200 targets, 343 objects show significant Hα emission lines. The gas-phase metallicity is from [N ii] λ6584/Hα line ratio, after excluding possible...
We report a deficiency of luminous Lyman break galaxies (LBGs) with large rest-frame equivalent width (EWrest) Lyα emission at z ~ 5-6. Combining our spectroscopic sample LBGs 5 and those from the literature, we found that 5-6 generally show weak emissions, while faint wide range EWrest tend to have strong (EWrest ≳ 20 Å) emissions; i.e., there is in LBGs. There seems be threshold UV luminosity for deficiency; it M1400 = -21.5 -21.0 mag, which close or somewhat brighter than M* function 6....
We present the results of spectral energy distribution (SED) fitting analysis for Lyman break galaxies (LBGs) at z ∼ 5 in Great Observatories Origins Deep Survey North (GOODS-N) and its flanking fields (the GOODS-FF). With publicly available Infrared Array Camera (IRAC) images GOODS-N IRAC data GOODS-FF, we constructed rest-frame UV to optical SEDs a large sample (∼100) UV-selected 5. Comparing observed with model generated population synthesis code, derived best-fit set parameters (stellar...
(abridged) We present results of a search for Lyman break galaxies (LBGs) at z ~ 5 in 618 square-arcmin field including the HDF-N taken by Subaru Prime Focus Camera. Utilizing published redshift data and its flanking fields, color selection criteria are chosen so that LBGs picked out most efficiently least contaminated foreground objects. The numbers LBG candidates detected 310 23.0 < I_c 25.5. rest-frame UV luminosity function(LF) is derived statistically. fraction contamination estimated...
The Prime Focus Spectrograph (PFS) is an optical/near-infrared multifiber spectrograph with 2394 science fibers distributed across a 1.3-deg diameter field of view at the Subaru 8.2-m telescope. wide wavelength coverage from 0.38 μm to 1.26 μm, resolving power 3000, simultaneously strengthens its ability target three main survey programs: cosmology, galactic archaeology and galaxy/AGN evolution. A medium resolution mode 5000 for 0.71 0.89 will also be available by simply exchanging...
The origin of color gradients in elliptical galaxies is examined by comparing model with those observed the Hubble Deep Field. models are constructed so as to reproduce local either a metallicity gradient or an age gradient. By looking-back sequence function redshift, age-metallicity degeneracy solved. at z = 0.1 1.0 agree excellently predicted gradient, while they deviate significantly from even ∼ 0.3, and deviation becomes larger increasing redshift. This result does not depend on...
We have studied Leo A, an isolated and extremely gas-rich dwarf irregular galaxy of very low stellar mass metallicity. Ages the populations in A range from ~10 Myr to Gyr. Here we report discovery old halo a sharp edge. also find that distribution stars extends beyond gaseous envelope galaxy. Therefore, by its structure as well content, is found resemble massive disk galaxies. This implies galaxies are able develop complex structures, challenging contemporary understanding evolution.
We present a kinematic analysis of the globular cluster(GC) system in giant elliptical galaxy (gE) NGC 4636 Virgo cluster. Using photometric and spectroscopic database 238 GCs, we have investigated kinematics GC system. The shows weak overall rotation, which is dominated by red GCs. However, both blue GCs show some rotation inner region at R<4.3'. velocity dispersion for all derived to be sigma_p = 225{+12-9} km/s. (sig=251 km/s) slightly larger than that (sig=205 km/s). dispersions about...
Abstract The FIBRE-pac (FMOS image-based reduction package) is an IRAF-based tool for the fiber multiple-object spectrograph (FMOS) of Subaru telescope. To reduce FMOS images, a number special techniques are necessary, because each image contains about 200 separate spectra with airglow emission lines variable in spatial and time domains, complicated throughput patterns masks. In spite these features, almost all processes, except few steps, carried out automatically by scripts text format,...
The Prime Focus Spectrograph (PFS) of the Subaru Measurement Images and Redshifts (SuMIRe) project has been endorsed by Japanese community as one main future instruments 8.2-meter telescope at Mauna Kea, Hawaii. This optical/near-infrared multi-fiber spectrograph targets cosmology with galaxy surveys, Galactic archaeology, studies galaxy/AGN evolution. Taking advantage Subaru's wide field view, which is further extended recently completed Wide Field Corrector, PFS will enable us to carry out...
We try to constrain the gas inflow and outflow rate of star-forming galaxies at z ∼ 1.4 by employing a simple analytic model for chemical evolution galaxies. The sample is constructed based on large near-infrared spectroscopic observed with Subaru/FMOS. gas-phase metallicity measured from [N ii] λ6584/Hα emission line ratio mass derived extinction corrected Hα luminosity assuming Kennicutt–Schmidt law. least-χ2 fittings gas-mass fraction, stellar mass, model. joint χ2 fitting shows that...
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 ~ 1.6-2.7Å. An international collaboration developing this...
We have started PISCES project; a panoramic imaging and spectroscopic survey of distant clusters on Subaru. It exploits the unique wide-field capability Suprime-Cam, which provides $34^{\prime} \times 27^{\prime}$ field view corresponding to physical area $16 13 \,\mathrm{Mpc}^2$ at $z \sim 1$. plan target 15 $0.4 \lesssim z 1.3$. report our first results concerning inner structures large-scale two = 0.55$ 0.83 together with earlier 0.41$ cluster. The photometric redshift technique has been...
We report the multi-wavelength identification of X-ray sources found in Subaru-XMM-Newton Deep Survey (SXDS) using deep imaging data covering wavelength range between far-UV to mid-IR. select a primary counterpart each source by applying likelihood ratio method R-band, 3.6micron, near-UV, and 24micron catalogs as well matching AGN candidates selected 1.4GHz radio i'-band variability surveys. Once Galactic stars, ultra-luminous nearby galaxy, clusters galaxies are removed there 896 sample....
We present the results from a large near-infrared spectroscopic survey with Subaru/FMOS (\textit{FastSound}) consisting of $\sim$ 4,000 galaxies at $z\sim1.4$ significant H$\alpha$ detection. measure gas-phase metallicity [N~{\sc ii}]$\lambda$6583/H$\alpha$ emission line ratio composite spectra in various stellar mass and star-formation rate bins. The resulting mass-metallicity relation generally agrees previous studies obtained similar redshift range to that our sample. No clear dependence...
ABSTRACT We conducted observations of 12 CO( J = 5–4) and dust thermal continuum emission toward 20 star-forming galaxies on the main sequence at z ∼ 1.4 using ALMA to investigate properties interstellar medium. The sample are chosen trace distributions in diagrams stellar mass versus star formation rate metallicity. detected CO lines from 11 galaxies. molecular gas is derived by adopting a metallicity-dependent CO-to-H 2 conversion factor assuming CO(5–4)/CO(1–0) luminosity ratio 0.23....
We performed B- and R-band surface photometry for E/S0 galaxies in the nearby rich cluster Abell 2199 to investigate their B-R color gradients [d(B-R)/d log r]. Our aims are study statistical properties of and, by comparing them with those less dense environments, examine environmental dependence elliptical galaxies. studied distribution found that mean value is -0.09 ± 0.04 mag dex-1, which can be converted a metallicity gradient (d Z/d r) -0.3 0.1. The seems comparable expected recent...
We report initial results for spectroscopic observations of candidates Lyman Break Galaxies (LBGs) at $z\sim5$ in a region centered on the Hubble Deep Field-North by using Faint Object Camera and Spectrograph attached to Subaru Telescope. Eight objects with $I_C\leq25.0$ mag, including one AGN, are confirmed be $4.5