A5075402794- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Galaxies: Formation, Evolution, Phenomena
- Adaptive optics and wavefront sensing
- Superconducting and THz Device Technology
- Advanced Thermodynamic Systems and Engines
- Pulsars and Gravitational Waves Research
- Spacecraft and Cryogenic Technologies
- Gamma-ray bursts and supernovae
- Astronomical Observations and Instrumentation
- Calibration and Measurement Techniques
- CCD and CMOS Imaging Sensors
- Particle Accelerators and Free-Electron Lasers
- Geophysics and Sensor Technology
- Astro and Planetary Science
- Infrared Target Detection Methodologies
- Astrophysics and Star Formation Studies
- Scientific Research and Discoveries
- Particle accelerators and beam dynamics
- Radiation Detection and Scintillator Technologies
- Nuclear Physics and Applications
- Optical Systems and Laser Technology
- Particle Detector Development and Performance
- Advanced X-ray Imaging Techniques
- Advanced Frequency and Time Standards
Institute of Space and Astronautical Science
2017-2022
Japan Aerospace Exploration Agency
2017-2020
Tohoku University
2003-2016
The University of Tokyo
2009-2016
University of California, Riverside
2012
Astronomical Institute of the Slovak Academy of Sciences
2008-2011
National Astronomical Observatory of Japan
2006-2009
Tokyo University of Science
2009
University of Hawaii System
2009
Subaru (Japan)
2008
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 extreme outer Galaxy (EOG), the region with a Galactic radius of more than 18 kpc, is known to have very low metallicity, about one-tenth that solar neighborhood. We obtained deep near-infrared (NIR) images two young ($\sim$0.5 Myr) star-forming clusters are one most distant embedded in EOG. find both fraction stars NIR excess, which originates from circumstellar dust disk at radii $\leq$0.1 AU, significantly lower those Our results suggest forming low-metallicity environment experience...
We present the first wide-field H-alpha imaging survey around distant cluster RXJ1716.4+6708 at z=0.81 with a narrow-band filter on MOIRCS/Subaru, down to SFR(Ha)~1Msun/yr. Combining MIR AKARI, we compare unobscured and obscured star formation activities in cluster. find that both emitters galaxies avoid centre their spatial distribution is quite similar. Most of show blue colours, but some red sequence. The tend be systematically redder than probably due heavy dust extinction....
We present the results of near-infrared multi-object spectroscopic observations for 37 BzK-color-selected star-forming galaxies conducted with MOIRCS on Subaru Telescope. The sample is drawn from Ks-band-selected catalog Deep Survey in GOODS-N region. About half our samples are selected publicly available 24 μm-source Multiband Imaging Photometer Spitzer board Space Hα emission lines detected 23 galaxies, which median redshift 2.12. derived star formation rates (SFRs) extinction-corrected...
We studied near-infrared disk fractions of six young clusters in the low-metallicity environments with [O/H$] \sim -0.7$ using deep $JHK$ images Subaru 8.2\,m telescope. found that fraction declines rapidly $<$1\,Myr, which is much faster than $\sim$5--7\,Myr observed for solar-metallicity clusters, suggesting lifetime shortens decreasing metallicity possibly an $\sim$$10^Z$ dependence. Since shorter reduces time available planet formation, this could be one major reasons strong...
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 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 a pilot narrow-band survey of H-alpha emitters at z=2.2 in the Great Observatories Origins Deep Survey North (GOODS-N) field with MOIRCS instrument on Subaru telescope. The reached 3 sigma limiting magnitude 23.6 (NB209) which corresponds to line flux 2.5 x 10^-17 erg s^-1 cm^-2 over 56 arcmnin^2 contiguous area (excluding shallower area). From this survey, we have identified 11 and one AGN basis excesses photometric redshifts. obtained spectra for seven new objects among them,...
Abstract We used very deep near-infrared imaging data taken with the Multi-Object InfraRed Camera and Spectrograph (MOIRCS) on Subaru Telescope to investigate number counts of Distant Red Galaxies (DRGs). observed a $4' \times 7'$ field in Great Observatories Origins Deep Survey-North (GOODS-N), our reached $J=24.6$ $K=23.2$ ($5\,\sigma$, Vega magnitude). The surface density DRGs selected by $J-K \gt 2.3 J-K 2.3$ is $2.35 \pm 0.31 \,\mathrm{arcmin}^{-2}$ at $K &lt; 22$ $3.54 0.38 23$,...
We have developed high dispersion VPH (volume phase holographic) grisms with zinc selenide (ZnSe) prisms for the cryogenic optical system of MOIRCS (Multi-Object near InfraRed Camera and Spectrograph) Y-, J-, H- K- band observations. fabricated gratings using a hologram resin. After several heat cycles at between room temperature 120 K, were assembled to by gluing two ZnSe prisms. Several also carried out before being installed into MOIRCS. measured efficiencies in laboratory, found them be...
Currently, the Japanese gravitational wave laser interferometer KAGRA is under construction in Kamioka mine. As one main feature, it will employ sapphire mirrors operated at a temperature of 20 K to reduce impact from thermal noise. To seismic noise, also be suspended multi-stage pendulums. Thus heat load deposited by absorption circulating light as well radiation need extracted through last suspension stage. This stage consist four thin fibers with larger heads necessary connect both mirror...
This paper reports on the optical properties, outgassing rate, and cryogenic performance of surface finishing we have adopted for large baffles absorbing stray light in KAGRA, an advanced interferometer detecting gravitational waves. The is based electroless nickel-phosphorus-tungsten (NiPW) plating, applicable to area up ~ 800 mm diameter, achieves less than 3% total reflectance against a beam at 1064 nm with reasonable scattering distribution 0.05/sr. rate from black coating meets our...
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 investigate the X-ray properties of K-band-selected galaxies at redshift 2 < z 4 by using our deep near-infrared images obtained in Multi-Object Infrared Camera and Spectrograph Deep Survey project published Chandra source catalog. Sixty-one sources with 2–10 keV luminosity LX = 1042–1044 erg s−1 are identified K-selected we found that they exclusively (90%) associated massive objects a stellar mass larger than 1010.5 M☉. Our results consistent idea MBH/Mstr ratio 2–4 is similar to...
KAGRA is a project to construct cryogenic interferometric gravitational wave detector in Japan. Its mirrors and the lower parts of suspension systems will be cooled 20 K order reduce thermal noise, one fundamental noise sources. One key features KAGRAʼs cooling system that it keep without introducing vibration. This paper describes current status design, manufacture testing system.
We present the results of deep near-infrared imaging observations z=3.1 proto-cluster region in SSA22a field taken by MOIRCS mounted on Subaru Telescope. observed a 21.7 arcmin^2 to depths J=24.5, H=24.3, and K=23.9 (5 sigma). examine distribution K-selected galaxies at z~3 using simple color cut for distant red (DRGs) as well photometric-redshift selection technique. The marginal density excess DRGs photo-z selected objects are found around two most luminous Ly alpha blobs (LABs)....
KAGRA is the cryogenic interferometric gravitational wave telescope designed for direct detection of waves from astronomical sources. To achieve best sensitivity, one most difficult challenges cooling mirrors to 20K reduce thermal noise. We developed four cryostats and sixteen very-low-vibration cryocooler units accomplish our purpose. In this paper, we describe outline design fabrication, results performance test units.
An accelerator test facility, t-ACTS, established at Research Center for Electron Photon Science, Tohoku University, equips an injector consisted with a thermionic RF gun together energy filter and 3 m traveling wave accelerating structure. A long-period undulator has been also installed provide THz superradiance. Velocity bunching scheme proposed by Serafini Ferrario is employed ultra-short electron pulses production. non-relativistic bunch, which slightly slower than the velocity of light,...
In interferometric cryogenic gravitational wave detectors, there are plans to cool mirrors and their suspension systems (payloads) in order reduce thermal noise, that is, one of the fundamental noise sources. Because large payload masses (several hundred kg total) isolation, a cooling time several months is required. Our calculation shows high-emissivity coating (e.g. diamond-like carbon (DLC) coating) can effectively by enhancing radiation heat transfer. Here, we have experimentally...
MOIRCS (Multi-Object InfraRed Camera and Spectrograph) is one of the second generation instruments for Subaru Telescope. This instrument under construction by National Astronomical Observatory Japan Tohoku University. It has imaging multi-object spectroscopy (MOS) capabilities in wavelength range from 0.85 μm to 2.5 with 4' x 7' F.O.V. The focal plane imaged onto two 2048 pixel HAWAII-2 HgCdTe arrays a scale 0."12 pixel<sup>-1</sup> through independent optical trains. design optimized...