A5038961128- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Astrophysics and Star Formation Studies
- Astrophysics and Cosmic Phenomena
- Astronomical Observations and Instrumentation
- Radio Astronomy Observations and Technology
- Particle physics theoretical and experimental studies
- Adaptive optics and wavefront sensing
- Astro and Planetary Science
- Quantum Chromodynamics and Particle Interactions
- Pulsars and Gravitational Waves Research
- Dark Matter and Cosmic Phenomena
- Scientific Research and Discoveries
- High-Energy Particle Collisions Research
- Spectroscopy and Laser Applications
- Planetary Science and Exploration
- CCD and CMOS Imaging Sensors
- Analytical chemistry methods development
- Semiconductor Lasers and Optical Devices
- Neutrino Physics Research
- Electrochemical Analysis and Applications
- Black Holes and Theoretical Physics
Kyoto University
2015-2024
Hiroshima University
2000-2024
Tokyo University of Science
2019-2021
Mie University
1975-2015
Tohoku University
2010
University of Hawaii System
1996-2010
Higashihiroshima Medical Center
2010
Tokyo Institute of Technology
2010
Gunma Astronomical Observatory
2010
The University of Tokyo
1976-2008
We investigate the cosmological evolution of hard X-ray luminosity function (HXLF) active galactic nuclei (AGNs) in 2-10 keV range 1041.5-1046.5 ergs s-1 as a redshift up to 3. From combination surveys conducted at photon energies above 2 with HEAO 1, ASCA, and Chandra, we construct highly complete (>96%) sample consisting 247 AGNs over wide flux 10-10 3.8 × 10-15 cm-2 (2-10 keV). For our purpose, develop an extensive method calculating intrinsic (before absorption) HXLF absorption (NH)...
We report an extensive search for Lyman-alpha emitters (LAEs) at z=6.5 in the Subaru Deep Field. Subsequent spectroscopy with and Keck identified eight more LAEs, giving a total of 17 spectroscopically confirmed LAEs z=6.5. Based on this spectroscopic sample 17, complemented by photometric 58 we have derived accurate luminosity function z=6.5, which reveals apparent deficit bright end ~0.75 mag fainter L*, compared that observed z=5.7. The difference LAE functions between z=5.7 6.5 is...
We present deep optical imaging observations of 2 square degree area, covered by the Cosmic Evolution Survey (COSMOS), made prime-focus camera (Supreme-Cam) on 8.2 m Subaru Telescope. Observations were done in six broadband [B (4459.7 Å), g' (4723.1 V (5483.8 r' (6213.0 i' (7640.8 z' (8855.0 Å)] and one narrowband (NB816) filters. A total 106 galaxies detected to ~ 26.5 mag. These data, combined with at u* K-band are used construct photometric catalogs for COSMOS, measure their redshifts,...
We compare a large sample of galaxies between 0.5<z<2.6 with theoretical predictions for how the optical diagnostic line ratios in galaxy ensembles change as function cosmic time. show that star forming at high redshift (z>1.5) are consistent model which ISM conditions more extreme than seen global spectra local galaxies. speculate our may be dominated by HII regions similar to clumpy, dense star-forming complexes Antennae and M82. The transition local-type occurs 0.8<z<1.5. conclude...
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...
The first detected gravitational wave from a neutron star merger was GW170817. In this study, we present J-GEM follow-up observations of SSS17a, an electromagnetic counterpart SSS17a shows 2.5-mag decline in the $z$-band 1.7 days to 7.7 after merger. Such rapid is not comparable with supernovae light curves at any epoch. color also evolves rapidly and becomes redder for later epochs; $z-H$ changed by approximately 2.5 mag period 0.7 days. evolution both optical brightness are consistent...
We report the source size distribution, as measured by ALMA millimetric continuum imaging, of a sample 13 AzTEC-selected submillimeter galaxies (SMGs) at –6. Their infrared luminosities and star formation rates (SFRs) are 2– ∼200–600 yr−1, respectively. The sizes these SMGs range from 010 to 038, with median 020 (FWHM), corresponding circularized effective radius () kpc, comparable typical stellar component in compact quiescent (cQGs)— kpc. surface SFR density our is yr−1 kpc−2, that seen...
We report the properties of 35 robust candidate Lyα blobs (LABs), which are larger than 16 arcsec2 in isophotal area and brighter 0.7 × 10-16 ergs s-1 cm-2, located around protocluster region at redshift z = 3.1 discovered by Steidel et al. SSA22 field, based on wide-field (31' 23') deep narrowband (NB497; 4977 Å, FWHM 77 Å) broadband (B, V, R) images taken with prime-focus camera Subaru Telescope. The two previously known giant LABs most luminous largest our survey volume 1.3 105 Mpc3....
The gamma-ray burst (GRB) 050904 at z = 6.3 provides the first opportunity of probing intergalactic medium (IGM) by GRBs epoch reionization. Here we present a spectral modeling analysis optical afterglow spectrum taken Subaru Telescope, aiming to constrain reionization history. shows clear damping wing wavelengths redward Lyman break, and shape can be fit either damped Ly alpha system with column density log (N_HI/cm^{-2}) ~ 21.6 redshift close detected metal absorption lines (z_metal...
Abstract We present the properties of Ly$\alpha$ emitters (LAEs) at $z=5.7$ in Subaru Deep Field. A photometric sample 89 LAE candidates was constructed from narrow-band data down to $\mathit{NB816} = 26.0$ (AB) a continuous $725 \,\mathrm{arcmin}^2$ area. Spectra 39 objects satisfying selection criteria for LAEs were obtained with and Keck II Telescopes, among which 28 confirmed LAEs, one nearby galaxy, eight unclassified. also spectra another 24 NB816-excess field, identifying six...
We present results of our large area survey for z'-band dropout galaxies at z = 7 in a 1568 arcmin2 sky covering the SDF and GOODS-N fields. Combining ultra-deep Subaru/Suprime-Cam z'- y-band (λeff 1 μm) images with legacy data Subaru Hubble Space Telescope, we have identified 22 bright z-dropout down to y 26, one which has spectroscopic redshift 6.96 determined from Lyα emission. The luminosity function yields best-fit Schechter parameters ϕ* 0.69+2.62−0.55 × 10−3 Mpc−3, M*UV −20.10 ± 0.76...
We obtained a deep wide-field (32' ? 24') narrowband (?c = 4977?,?? 77?) image of field including the protocluster at z 3.1 in SSA22a studied by Steidel et al. using Subaru Telescope. The we observed is about 10 times as large that detected 283 highly confident strong Ly? emitter candidates ~ down to 25.8 AB mag with equivalent width larger than 154 ?. These show nonuniform distribution beltlike region high surface density, which found extend over ~60 Mpc comoving scale. average number...
We have performed a deep optical imaging survey using narrowband filter ($NB921$) centered at $\lambda =$ 9196 \AA ~ together with $i^\prime$ and $z^\prime$ broadband filters covering an 814 arcmin$^2$ area of the Subaru Deep Field. obtained sample 73 strong $NB921$-excess objects based on following two color criteria; $z^\prime - NB921 > 1$ $i^\prime z^\prime 1.3$. then spectroscopy nine in our sample, identified least Ly$\alpha$ emitters at$z=6.541 \pm 0.002$ $z=6.578 0.002$, each which...
We present an investigation into how well the properties of accretion flow on to a supermassive black hole may be coupled those overlying hot corona. To do so, we specifically measure characteristic spectral index, Γ, power-law energy distribution, over range 2–10 keV, for X-ray selected, broad-lined radio-quiet active galactic nuclei (AGN) up z ∼ 2 in Cosmic Evolution Survey (COSMOS) and Extended Chandra Deep Field South (E-CDF-S). test previously reported dependence between Γ mass, full...
Abstract Recent detection of gravitational waves from a neutron star (NS) merger event GW170817 and identification an electromagnetic counterpart provide unique opportunity to study the physical processes in NS mergers. To derive properties ejected material merger, we perform radiative transfer simulations kilonova, optical near-infrared emissions powered by radioactive decays r-process nuclei synthesized merger. We find that observed emission lasting for &gt;10 d is explained 0.03 M⊙...
We present the results of new near-IR spectroscopic observations passive galaxies at z ≳ 1.4 in a concentration BzK-selected COSMOS field. The have been conducted with Subaru/MOIRCS, and resulted absorption lines and/or continuum detection for 18 out 34 objects. This allows us to measure redshifts sample that is almost complete KAB = 21. photometric are found fair agreement overall redshifts, standard deviation ∼0.05; however, ∼30% objects systematically underestimated by up ∼25%. show these...
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,...
We present ALMA observations of the [C ii] line and far-infrared (FIR) continuum a normally star-forming galaxy in reionization epoch, z = 6.96 Lyα emitter (LAE) IOK-1. Probing to sensitivities σline 240 μJy beam−1 (40 km s−1 channel) σcont 21 beam−1, we found undetected both continuum. Comparison ultraviolet (UV)–FIR spectral energy distribution (SED) IOK-1, including our limit, with those several types local galaxies (including effects cosmic microwave background, CMB, on FIR continuum)...
Abstract The Subaru Deep Field (SDF) project is a program of Observatory to carry out deep galaxy survey over blank field as large $34' \times 27'$. consists very multi-band optical imaging, near-infrared imaging for smaller portions the field, and follow-up spectroscopy. major scientific goals are construct samples Lyman-break galaxies at $z \simeq 4 \hbox{--} 5$ Lyman alpha emitters 5.7$ 6.6, make detailed studies these high-redshift populations. In this paper, we describe observations...
We have combined deep BRIz' imaging over 2x940 arcmin^2 fields obtained with the Suprime-Cam on Subaru telescope JKs SOFI camera at New Technology Telescope to search for high-redshift massive galaxies. K-band selected galaxies been identified an area of ~920 K_Vega=19.2, which 320 are complete K_Vega=20. The BzK selection technique was used obtain samples ~500 candidate star-forming (sBzKs) and ~160 massive, passively-evolving (pBzKs), both 1.4 5 criterion we also ~850 extremely red objects...
We report the discovery of a large-scale structure Lyman alpha emitters (LAEs) at z=4.86 based on wide-field imaging with prime-focus camera (Suprime-Cam) Subaru telescope. observed 25' x 45' area Deep Field in narrow band (NB, lambdaC=7126 A and FWHM=73 A) together R i'. isolate from these data 43 LAE candidates down to NB=25.5 mag using color criteria. Follow-up spectroscopy five suggests contamination by low-z objects be ~ 20%. find that are clustered an elongated region sky 20 Mpc width...
We report the discovery of a giant Lyα emitter (LAE) with Spitzer/Infrared Array Camera (IRAC) counterpart near reionization epoch at z = 6.595. The LAE is found from extensive 1 deg2 Subaru narrowband survey for 6.6 LAEs in Subaru/XMM-Newton Deep Survey (SXDS) field, and subsequently identified by deep spectroscopy Keck/DEIMOS Magellan/IMACS. Among our 207 candidates, this not only brightest object L(Lyα) 3.9 ± 0.2 × 1043 erg s−1 volume 106 Mpc3, but also spatially extended nebula largest...
view Abstract Citations (118) References (63) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Surface Photometry of Barred Spiral Galaxies Ohta, Kouji ; Hamabe, Masaru Wakamatsu, Ken-Ichi Detailed surface photometry has been made for six early-type barred spiral galaxies with use high-resolution photographic plates. The main results obtained by detailed examination several kinds profiles are the following: (1) On azimuthal luminosity along concentric...