Naoki Yasuda
A5107837035- Gamma-ray bursts and supernovae
- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Stellar, planetary, and galactic studies
- Astronomical Observations and Instrumentation
- Semiconductor materials and devices
- Advancements in Semiconductor Devices and Circuit Design
- Astrophysics and Cosmic Phenomena
- Adaptive optics and wavefront sensing
- Astrophysical Phenomena and Observations
- Integrated Circuits and Semiconductor Failure Analysis
- Astrophysics and Star Formation Studies
- Stress Responses and Cortisol
- Pulsars and Gravitational Waves Research
- Ferroelectric and Negative Capacitance Devices
- Adrenal Hormones and Disorders
- CCD and CMOS Imaging Sensors
- Radio Astronomy Observations and Technology
- Growth Hormone and Insulin-like Growth Factors
- Advanced Computational Techniques and Applications
- Advanced Memory and Neural Computing
- Sexual function and dysfunction studies
- Scientific Research and Discoveries
- International Business and FDI
- Distributed and Parallel Computing Systems
Kavli Institute for the Physics and Mathematics of the Universe
2014-2024
Rikkyo University
2015-2024
The University of Tokyo
2012-2024
Tokyo University of Science
1994-2020
Hyogo Medical University
2018
Keio University
2014
Hoshi University
2014
Chubu University
2013
Toshiba (Japan)
1996-2012
Tohoku University
2010-2012
We describe the algorithm that selects main sample of galaxies for spectroscopy in Sloan Digital Sky Survey from photometric data obtained by imaging survey. Galaxy properties are measured using Petrosian magnitude system, which measures flux apertures determined shape surface brightness profile. The metric aperture used is essentially independent cosmological dimming, foreground extinction, sky brightness, and galaxy central brightness. consists with r-band r < 17.77 half-light 24.5...
We present Advanced Camera for Surveys, NICMOS, and Keck adaptive-optics-assisted photometry of 20 Type Ia supernovae (SNe Ia) from the Hubble Space Telescope (HST) Cluster Supernova Survey. The SNe were discovered over redshift interval 0.623 < z 1.415. Of these Ia, 14 pass our strict selection cuts are used in combination with world's sample to derive best current constraints on dark energy. new 10 beyond = 1, thereby nearly doubling statistical weight HST-discovered this redshift. Our...
We report measurements of ΩM, ΩΛ, and w from 11 supernovae (SNe) at z = 0.36-0.86 with high-quality light curves measured using WFPC2 on the Hubble Space Telescope (HST). This is an independent set high-redshift SNe that confirms previous SN evidence for accelerating universe. The available photometry make it possible these alone to provide cosmological parameters comparable in statistical weight results. Combined earlier Supernova Cosmology Project data, new yield a measurement mass density...
We report on work to increase the number of well-measured Type Ia supernovae (SNe Ia) at high redshifts. Light curves, including signal-to-noise Hubble Space Telescope data, and spectra six SNe that were discovered during 2001, are presented. Additionally, for two with z > 1, we present ground-based J-band photometry from Gemini Very Large Telescope. These among most distant which near-IR observations have been obtained. add these together other data sets recently become available in...
Abstract We have built an 80-mega pixels ($10240 \times 8192$) mosaic CCD camera, called Suprime-Cam, for the wide-field prime focus of 8.2 m Subaru telescope. Suprime-Cam covers a field view $34' 27'$, unique facility among 8–10 class telescopes, with resolution ${0\rlap {.}{}^{\mathrm {\prime \prime }}202}$ per pixel. The focal plane consists ten high-resistivity $2\mathrm{k} 4\mathrm{k}$ CCDs developed by MIT Lincoln Laboratory, which are cooled large Stirling-cycle cooler. readout...
We present measurements of the Hubble diagram for 103 Type Ia supernovae (SNe) with redshifts 0.04 < z 0.42, discovered during first season (Fall 2005) Sloan Digital Sky Survey-II (SDSS-II) Supernova Survey. These data fill in redshift "desert" between low- and high-redshift SN surveys. combine SDSS-II new distance estimates published from ESSENCE survey, Legacy Survey, Space Telescope, a compilation nearby measurements. Combining Baryon Acoustic Oscillations SDSS Luminous Red Galaxy sample...
In the course of its commissioning observations, Sloan Digital Sky Survey (SDSS) has produced one largest redshift samples galaxies selected from CCD images. Using 11,275 complete to r* = 17.6 over 140 deg2, we compute luminosity function in band a range -23 < M -16 (for h 1). The result is well-described by Schechter with parameters ϕ* (1.46 ± 0.12) × 10-2 h3 Mpc-3, M* -20.83 0.03, and α -1.20 0.03. implied density j ≈ (2.6 0.3) 108h L⊙ Mpc-3. We find that surface brightness selection...
In this paper, we describe the optical imaging data processing pipeline developed for Subaru Telescope's Hyper Suprime-Cam (HSC) instrument. The HSC Pipeline builds on prototype being by Large Synoptic Survey Data Management system, adding customizations HSC, large-scale capabilities, and novel algorithms that have since been reincorporated into LSST codebase. While designed primarily to reduce Strategic Program (SSP) data, it is also recommended reducing general-observer data. includes high...
Abstract The Hyper Suprime-Cam (HSC) is an 870 megapixel prime focus optical imaging camera for the 8.2 m Subaru telescope. wide-field corrector delivers sharp images of 0${^{\prime\prime}_{.}}$2 (FWHM) in HSC-i band over entire 1${^{\circ}_{.}}$5 diameter field view. collimation with respect to axis primary mirror done hexapod actuators, mechanical accuracy which a few microns. Analysis remaining wavefront error off-focus stellar reveals that components meets design specifications. While...
The Sloan Digital Sky Survey-II (SDSS-II) has embarked on a multi-year project to identify and measure light curves for intermediate-redshift (0.05 < z 0.35) Type Ia supernovae (SNe Ia) using repeated five-band (ugriz) imaging over an area of 300 sq. deg. survey region is stripe 2.5° wide centered the celestial equator in Southern Galactic Cap that been imaged numerous times earlier years, enabling construction deep reference image discovery new objects. Supernova observations are being...
We investigate the photometric properties of Lyman break galaxies (LBGs) at z = 3.5-5.2 based on large samples 2600 LBGs detected in deep (i' ≲ 27) and wide-field (1200 arcmin2) images taken Subaru Deep Field (SDF) Subaru/XMM-Newton (SXDF) using broadband B, V, R, i', z' filters. The selection criteria for LBG are examined with 85 spectroscopically identified objects, completeness contamination estimated from Monte Carlo simulations a photometric-redshift catalog Hubble Field-North. find...
The monochromatic illumination system is constructed to carry out in situ measurements of the response function mosaicked CCD imager used Sloan Digital Sky Survey (SDSS). outlined and results measurements, mostly during first 6 years SDSS, are described. We present reference functions for five colour passbands derived from these discuss column variations time, also their effects on photometry. effect arising various, slightly different associated detector systems that were give SDSS show...
Hyper Suprime-Cam (HSC) is an 870 Mega pixel prime focus camera for the 8.2 m Subaru telescope. The wide field corrector delivers sharp image of 0.25 arc-sec FWHM in r-band over entire 1.5 degree (in diameter) view. collimation with respect to optical axis primary mirror realized by hexapod actuators whose mechanical accuracy few microns. As a result, we expect have seeing limited most time. Expected median 0.67 i-band. sensor p-ch fully depleted CCD 200 micron thickness (2048 x 4096 15 μm...
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 We describe five broad-band filters and a narrow-band one for the Hyper Suprime-Cam (HSC) at prime focus of Subaru Telescope. Since HSC is practical successor to (SC), our filter set follows SC's SDSS g΄, r΄, i΄, z΄ filters, Y filter, Hα adopted as first filter. Filters are quite large; therefore, they constructed only by interference coatings. Based on draft specification guided that we made prototype which were evaluated laboratory, eventually used them in actual commissioning...
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...
Abstract We have developed an automated quick data analysis system for quality assurance (QA) Hyper Suprime-Cam (HSC). The was commissioned in 2012–2014, and has been offered general observations, including the HSC Subaru Strategic Program, since 2014 March. provides observers with information, such as seeing, sky background level, transparency, based on are acquired. Quick-look images validation of image focus also provided through interactive web application. is responsible automatic...
We investigate the photometric properties of 456 bright galaxies using imaging data recorded during commissioning phase Sloan Digital Sky Survey (SDSS). Morphological classification is carried out by correlating results several human classifiers. Our purpose to examine statistical color indices, scale lengths, and concentration indices as functions morphology for SDSS system. find that u'-g', g'-r', r'-i' colors match well with those expected from synthetic calculation spectroscopic energy...
We present multi-wave band optical imaging data obtained from observations of the Subaru/XMM-Newton Deep Survey (SXDS). The survey field, centered at R .A . = 02h18m00s, decl − 05°00'00'', has been focus a wide range multiwavelength observing programs spanning X-ray to radio wavelengths. A large part are carried out with Suprime-Cam on Subaru Telescope Mauna Kea in course "Observatory Projects." This paper describes our observations, reduction and analysis procedures employed,...
Abstract We present new results of a deep optical imaging survey using narrow band filter (NB921) centered at ${\lambda = 9196 \,\mbox{Å}}$ together with $B, V, R, i^\prime$, and $z^\prime$ broadband filters in the sky area Subaru Deep Field, which has been promoted as one legacy programs 8.2m Telescope. obtained photometric sample 58 $\mathrm{Ly}\,\alpha$ emitter candidates $z \approx 6.5 \hbox{--} 6.6$ among $\sim 180$ strong NB921-excess ($z^\prime-\mathit{NB921} \gt 1.0...
We report on early results from very deep and wide-field narrowband imaging a 543 arcmin2 area of the Subaru Deep Field. find 87 Lyα emitters (LAEs) at z = 4.86 ± 0.03 that are photometrically selected by combination two broad bands (R i') one narrow band (NB711; λc 7126 Å, Δλ 73 Å). derive luminosity functions (LFs) LAEs UV-continuum (rest frame 1700 Å) luminosity. The LFs show little evolution between 3.4 either in or emission. amplitude LAE LF tends to decline bright magnitudes more...
We present bright galaxy number counts in five broad bands (u', g', r', i', z') from imaging data taken during the commissioning phase of Sloan Digital Sky Survey (SDSS). The are derived two independent stripes scans along celestial equator, one each toward northern and southern Galactic cap, covering about 230 210 deg2, respectively. A careful study is made to verify reliability photometric catalog. For galaxies brighter than r* = 16, catalog produced by automated software examined against...