A5068116148- Astronomy and Astrophysical Research
- Adaptive optics and wavefront sensing
- Stellar, planetary, and galactic studies
- Astronomical Observations and Instrumentation
- Calibration and Measurement Techniques
- Prosthetics and Rehabilitation Robotics
- Galaxies: Formation, Evolution, Phenomena
- Optical Systems and Laser Technology
- Gamma-ray bursts and supernovae
- Muscle activation and electromyography studies
- Marine animal studies overview
- Underwater Acoustics Research
- Scientific Research and Discoveries
- CCD and CMOS Imaging Sensors
- Robotic Locomotion and Control
- Optical Polarization and Ellipsometry
- Animal Vocal Communication and Behavior
- Advanced optical system design
- Gaze Tracking and Assistive Technology
- Blind Source Separation Techniques
- Advanced Sensor and Energy Harvesting Materials
- Inertial Sensor and Navigation
- Traffic Prediction and Management Techniques
- Balance, Gait, and Falls Prevention
- solar cell performance optimization
Chuo University
2018-2022
National Astronomical Observatory of Japan
2009-2020
University of California, San Diego
2016-2020
National Institutes of Natural Sciences
2017-2018
Aoyama Gakuin University
2016-2017
Keio University
2016
AdTech Optics (United States)
2014
California Institute of Technology
2014
Optica
2014
Shibaura Institute of Technology
2014
The structure of humpback whale (Megaptera novaeangliae) songs was examined using information theory techniques. song is an ordered sequence individual sound elements separated by gaps silence. Song samples were converted into sequences discrete symbols both human and automated classifiers. This paper analyzes the in these symbol entropy estimators autocorrelation estimators. Both parametric nonparametric are applied to representing songs. results provide quantitative evidence consistent...
Abstract MOIRCS is a fully cryogenic near-infrared instrument for the 8.2 m Subaru Telescope. has two observation modes: wide-field imaging mode and multiobject spectroscopy mode. This paper describes mode, its specifications, actual performances that we confirmed through laboratory tests commissioning observations. The provides 4' $\times$ 7' field of view with pixel scale 0”.117pixel$^{-1}$ in wavelength range 0.85 to 2.5$\mu$ using cooled optics 2048 HgCdTe HAWAII-2 focal plane arrays....
We use very deep near-infrared (NIR) imaging data obtained in MOIRCS Deep Survey (MODS) to investigate the evolution of galaxy stellar mass function back z ∼ 3. The MODS reach J = 24.2, H 23.1, and K 23.1 (5σ, Vega magnitude) over 103 arcmin2 (wide) 25.1, 23.7, 24.1 28 (deep) GOODS-North region. wide NIR allow us measure number density galaxies down low (109–1010 M☉) even at high redshift with statistical accuracy. normalization decreases redshift, integrated becomes ∼8%–18% local value 2...
MOIRCS is a new Cassegrain instrument of Subaru telescope, dedicated for wide field imaging and multi-object spectroscopy in near-infrared. has been constructed jointly by Tohoku University the Telescope saw first light Sept., 2004. The commissioning observations to study both spectroscopic performance were conducted about one year. mounts two 2048 × HAWAII2 arrays provides view 4' x 7' with pixel scale 0."117. All-lens optical design optimized 0.8 2.5 μm no practical chromatic aberration....
The High-Contrast Coronographic Imager for Adaptive Optics (HiCIAO), is a coronographic simultaneous differential imager the new 188-actuator AO system at Subaru Telescope Nasmyth focus. It designed primarily to search faint companions, brown dwarves and young giant planets around nearby stars, but will also allow observations of disks stars emission line regions near other bright central sources. HiCIAO work in conjunction with adaptive optics system. as flexible, experimental instrument...
We present deep J-, H-, and Ks-band imaging data of the MOIRCS Deep Survey (MODS), which was carried out with Multi-Object Infrared Camera Spectrograph (MOIRCS) mounted on Subaru telescope in GOODS-North region. The reach 5sigma total limiting magnitudes for point sources J=23.9, H=22.8, Ks=22.8 (Vega magnitude) over 103 arcmin^2 (wide field). In 28 survey area, is ultra field MODS (deep field), depths J=24.8, H=23.4, Ks=23.8. spatial resolutions combined images are FWHM ~ 0.6 arcsec 0.5...
We describe Algorithms for Calibration, Optimized Registration, and Nulling the Star in Angular Differential Imaging (ACORNS-ADI), a new, parallelized software package to reduce high-contrast imaging data, its application data from SEEDS survey. implement several new algorithms, including method register saturated images, trimmed mean combining an image sequence that reduces noise by up ~20%, robust computationally fast compute sensitivity of observation everywhere on field-of-view without...
The properties of K-band selected galaxies (K_AB<24) in the z = 3.09 SSA22 protocluster field are studied. 430 at 2.6 < z_phot 3.6 as potential members a 112 arcmin^2 area based on their photometric redshifts. We find that \approx 20% massive with stellar masses >10^11 M_sun \sim 3.1 have colors consistent those quiescent ages > 0.5 Gyr. This fraction increases to 50% after correcting for unrelated foreground/background objects. also 30% heavily reddened dusty star-forming galaxies. Few such...
IRIS is a near-infrared (0.84 to 2.4 micron) integral field spectrograph and wide-field imager being developed for first light with the Thirty Meter Telescope (TMT). It mounts advanced adaptive optics (AO) system NFIRAOS has integrated on-instrument wavefront sensors (OIWFS) achieve diffraction-limited spatial resolution at wavelengths longer than 1 μm. With moderate spectral (R ~ 4000 – 8,000) large bandpass over continuous of view, will open new opportunities in virtually every area...
We present the results of wide-field deep JHK imaging SSA22 field using MOIRCS instrument equipped with Subaru telescope. The observed is 112 arcmin^2 in area, which covers z=3.1 protocluster characterized by overdensities Ly Alpha emitters (LAEs) and Blobs (LABs). 5 sigma limiting magnitude K_{AB} = 24.3. extract potential members from K-selected sample multi-band photometric-redshift selection as well simple color cut for distant red galaxies (DRGs; J-K_{AB}>1.4). surface number density...
We present an overview of the design IRIS, infrared (0.84 - 2.4 micron) integral field spectrograph and imaging camera for Thirty Meter Telescope (TMT). With extremely low wavefront error (<30 nm) on-board sensors, IRIS will take advantage high angular resolution narrow adaptive optics system (NFIRAOS) to dissect sky at diffraction limit 30-meter aperture. a primary spectral 4000 spatial sampling starting 4 milliarcseconds, instrument create unparalleled ability explore redshift galaxies,...
We present the current optical design for IRIS Atmospheric Dispersion Corrector (ADC). The ADC is designed residual dispersions less than ~1 mas across a given passband at elevations of 25 degrees. Since last report, area Imager has increased by factor four, and pupil size from 75 to 90mm, both which contribute challenges with design. Several considerations have led design: dispersion, amount introduced distortion, glass transmission, availability, displacement. In particular, it was found...
Abstract We present the first measurement of clustering properties low-mass galaxies with a stellar mass down to $M_*\sim 10^9 M_{\odot}$ at 1$\lt z \lt $4 in 24.4 arcmin$^{2}$ GOODS-North region depth $K_\mathrm{AB}\sim$25. Luminous $K$-band have larger correlation length than faint galaxies. For color-selected samples 2$\lt \lt$4, distant red $J-K \gt$1.3 show large bias $b\sim$7.2$\pm$1.3 on scales up $\theta\sim$100$^{\prime\prime}$ or 3.1 comoving Mpc, while blue 0.5$\lt J-K $1.3 weak...
We present an overview of the design IRIS, infrared (0.85 - 2.5 micron) integral field spectrograph and imaging camera for Thirty Meter Telescope (TMT). With extremely low wavefront error (<30 nm) on-board sensors, IRIS will take advantage high angular resolution narrow adaptive optics system (NFIRAOS) to dissect sky at diffraction limit 30-meter aperture. a primary spectral 4000 spatial sampling starting 4 milliarcseconds, instrument create unparalleled ability explore redshift galaxies,...
In this paper, the prototype of assistive suit for lower limbs was developed. The based on an assist method with joint stiffness and antagonized angle control. comprises a system consisting pneumatic artificial muscle pull spring, which changes to correspond movement phase aims at coordinated motion assistance wearer. First, characteristics developed were tested. It confirmed that measured value followed target in relationship between torque angle. addition, there hysteresis value, but it...
This paper reports on an improvement to a feedforward controller for straight-fiber-type artificial muscle that can control the amount of contraction, stiffness, and contraction force by use experimental identification model. has higher rate than McKibben muscle. In previous study, we developed based mechanical However, this could not accurately stiffness or force. A feedback was necessary compensate lack accuracy, which increased system complexity. addition, calculations were so complex...
The Thirty Meter Telescope (TMT) first light instrument IRIS (Infrared Imaging Spectrograph) will complete its preliminary design phase in 2016. includes a near-infrared (0.85 - 2.4 micron) integral field spectrograph (IFS) and imager that are able to conduct simultaneous diffraction-limited observations behind the advanced adaptive optics system NFIRAOS. science cases have continued be developed new studies been investigated aid technical performance requirements. In this development phase,...
IRIS (InfraRed Imaging Spectrograph) is a first light near-infrared diffraction limited imager and integral field spectrograph being designed for the future Thirty Meter Telescope (TMT). optimized to perform astronomical studies across significant fraction of cosmic time, from our Solar System distant newly formed galaxies (Barton et al. [1]). We present selection innovative science cases that are unique in era upcoming space ground-based telescopes. focus on spectroscopy directly imaged...
HiCIAO, the High-Contrast Coronographic Imager for Adaptive Optics, is a coronographic simultaneous differential imager Subaru Telescope Nasmyth focus. It designed primarily to search faint companions, brown dwarves and young giant planets, around nearby stars, but will also allow observations of disks stars emission line regions near other bright central sources. HiCIAO work in conjunction with new 188 actuator adaptive optics system. as flexible, experimental instrument that grow from...
The Infra-Red Imaging Spectrograph (IRIS) is one of the three first light instruments for Thirty Meter Telescope (TMT) and only to directly sample diffraction limit.The instrument consists a parallel imager offaxis Integral Field (IFS) optimum use near infrared (0.84um-2.4um)Adaptive Optics corrected focal surface.We present an overview IRIS spectrograph that designed probe range scientific targets from dynamics morphology high-z galaxies studying atmospheres surfaces solar system objects,...
We describe an optical design of imager mode the IRIS instrument for Thirty Meter Telescope. is a fully-cryogenic diffraction-limited infrared camera and integral field spectrograph working in wavelength coverage from 0.84 to 2.4 microns. The covers 16.4" × FOV with 4096 detector array sampling 4 milli-arcsec/pix. There are two challenges performance which science cases require mode. 1) rms wavefront error should be less than 30 nm, 2) distortion corrected sufficiently achieve astrometric...
The Thirty Meter Telescope (TMT) with its first-light multi-conjugate adaptive optics system, NFIRAOS, and high-resolution imager, IRIS, is expected to take differential astrometric measurements an accuracy on the order of tens micro arcsec. This requires control, correction, characterization calibration a large number error sources uncertainties, many which have magnitudes much in excess this level accuracy. In addition designing observatory such that very high precision observations are...
IRIS is a diffraction limited instrument designed for first light of the Thirty Meter Telescope (TMT). It combines nearinfrared integral field spectrograph (lenslet array and mirror slicer) wide-field imager with platescales as small 4 mas. The project nearing end its final design phase will soon be ready fabrication. Our team has created wide variety prototypes solutions this advanced instrument. While many challenges like atmospheric dispersion correction saturation are particularly acute...