A5053815997- Gamma-ray bursts and supernovae
- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Astrophysics and Cosmic Phenomena
- Stellar, planetary, and galactic studies
- Astrophysical Phenomena and Observations
- Astronomical Observations and Instrumentation
- Pulsars and Gravitational Waves Research
- Astrophysics and Star Formation Studies
- Cosmology and Gravitation Theories
- Adaptive optics and wavefront sensing
- Neutrino Physics Research
- Nuclear Physics and Applications
- Scientific Research and Discoveries
- CCD and CMOS Imaging Sensors
- Astro and Planetary Science
- Radio Astronomy Observations and Technology
- Solar and Space Plasma Dynamics
- Dark Matter and Cosmic Phenomena
- Atomic and Subatomic Physics Research
- Geophysics and Gravity Measurements
- Particle physics theoretical and experimental studies
- Remote Sensing in Agriculture
- Advanced Vision and Imaging
- Magnetic confinement fusion research
Laboratoire de Physique Nucléaire et de Hautes Énergies
2024
Kavli Institute for the Physics and Mathematics of the Universe
2014-2023
The University of Tokyo
2014-2023
Lawrence Berkeley National Laboratory
2012-2023
Osaka University of Pharmaceutical Sciences
2023
Otsuma Women's University
2021
University of Utah
2014
Kavli Institute for Particle Astrophysics and Cosmology
2014
Stanford University
2014
University of California, Berkeley
2012
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 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...
We combine high redshift Type Ia supernovae from the first 3 years of Supernova Legacy Survey (SNLS) with other supernova (SN) samples, primarily at lower redshifts, to form a high-quality joint sample 472 SNe (123 low-$z$, 93 SDSS, 242 SNLS, and 14 {\it Hubble Space Telescope}). SN data alone require cosmic acceleration >99.9% confidence, including systematic effects. For dark energy equation state parameter (assumed constant out least $z=1.4$) in flat universe, we find $w =...
We present observational constraints on the nature of dark energy using Supernova Legacy Survey three-year sample (SNLS3) Guy et al. and Conley use 472 Type Ia supernovae (SNe Ia) in this sample, accounting for recently discovered correlations between SN luminosity host galaxy properties, include effects all identified systematic uncertainties directly cosmological fits. Combining SNLS3 data with full WMAP7 power spectrum, Sloan Digital Sky luminous red a prior Hubble constant H0 from SHOES,...
We report the detection of Deuterium absorption at redshift 2.525659 towards Q1243+3047. describe improved methods to estimate Hydrogen abundance ratio (D/H) in systems, including modeling continuum level, Ly-alpha forest and velocity structure absorption. Together with relative flux calibration, these give D/H = 2.42^+0.35_-0.25 x 10^-5 cm^-2 from our Keck-I HIRES spectra Q1243+3047, where error is uncertainty shape level amount D a minor second component. The measured likely primordial...
Stellar Explosions Stars that are born with masses greater than eight times of the Sun end their lives in luminous explosions known as supernovae. Over past decade, access to improved sky surveys has revealed rare types supernovae much more any those were before. Gal-Yam (p. 927 ) reviews these superluminous events and groups them into three classes share common observational physical characteristics. Gamma-ray bursts another type extreme explosive related death massive stars, which occur...
We use the Baryon Oscillation Spectroscopic Survey (BOSS) Data Release 9 (DR9) to detect and measure position of Baryonic Acoustic (BAO) feature in three-dimensional correlation function Lyman-α flux fluctuations at a redshift zeff = 2.4. The is clearly detected significance between 3 5 sigma (depending on broadband model method error covariance matrix estimation) consistent with predictions standard ΛCDM model. assess biases our method, stability possible systematic effects. fit resulting...
We present the Data Release 9 Quasar (DR9Q) catalog from Baryon Oscillation Spectroscopic Survey (BOSS) of Sloan Digital Sky III. The includes all BOSS objects that were targeted as quasar candidates during survey, are spectrocopically confirmed quasars via visual inspection, have luminosities Mi[z=2]<-20.5 (in a $\Lambda$CDM cosmology with H0 = 70 km/s/Mpc, $\Omega_{\rm M}$ 0.3, and $\Omega_{\Lambda}$ 0.7) either display at least one emission line full width half maximum (FWHM) larger than...
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,...
The SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS), a five-year spectroscopic survey of 10,000 deg^2, achieved first light in late 2009. One the key goals BOSS is to measure signature baryon acoustic oscillations distribution Ly-alpha absorption from spectra sample ~150,000 z>2.2 quasars. Along with measuring angular diameter distance at z\approx2.5, will provide direct measurement expansion rate Universe z > 2. biggest challenges achieving this goal an efficient target selection...
Abstract This paper presents the third data release of Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP), a wide-field multi-band imaging survey with 8.2 m telescope. HSC-SSP has three layers (Wide, Deep, and UltraDeep) different area coverages depths, designed to address wide array astrophysical questions. from includes 278 nights observing time covers about 670 deg2 in all five broad-band filters (grizy) at full depth (∼26 mag 5σ depending on filter) Wide layer. If we include partially...
Previously we used the Nearby Supernova Factory sample to show that Type Ia supernovae (SNe Ia) having locally star-forming environments are dimmer than SNe passive environments. Here use Constitution together with host galaxy data from GALEX independently confirm result. The effect is seen using both SALT2 and MLCS2k2 lightcurve fitting standardization methods, brightness differences of 0.094 ± 0.037 mag for 0.155 0.041 RV = 2.5. When combined our previous measurement 0.025 SALT2. If ratio...
As part of an on-going effort to identify, understand and correct for astrophysics biases in the standardization Type Ia supernovae (SNIa) cosmology, we have statistically classified a large sample nearby SNeIa into those located predominantly younger or older environments. This classification is based on specific star formation rate measured within projected distance 1kpc from each SN location (LsSFR). important refinement compared using local directly as it provides normalization relative...
We report the measurement of primordial D/H abundance ratio toward QSO HS 0105+1619. The column density neutral hydrogen in z ≃ 2.536 Lyman limit system is high, log N = 19.422 ± 0.009 cm-2, allowing for deuterium to be seen five series transitions. measured value 0105+1619 found 2.54 0.23 × 10-5. metallicity showing ≃0.01 solar, indicating that within errors. gas shows neutral, unlike previous systems were more highly ionized. Thus, determination becomes secure since we are measuring it...
The nearby supernova SN 2011fe can be observed in unprecedented detail. Therefore, it is an important test case for Type Ia (SN Ia) models, which may bring us closer to understanding the physical nature of these objects. Here, we explore how available and expected future observations used constrain explosion scenarios. We base our discussion on three-dimensional simulations a delayed detonation Chandrasekhar-mass white dwarf violent merger two dwarfs-realizations models appropriate most...
We present a new measurement of the optical Quasar Luminosity Function (QLF), using data from Sloan Digital Sky Survey-III: Baryon Oscillation Spectroscopic Survey (SDSS-III: BOSS). From SDSS-III Data Release Nine (DR9), we select uniform sample 22,301 i<=21.8 quasars over an area 2236 sq. deg with confirmed spectroscopic redshifts between 2.2<z<3.5, filling in key part luminosity-redshift plane for quasar studies. derive completeness survey through simulated photometry, and check this...
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...
Abstract Faint star-forming galaxies at z ∼ 2–3 can be used as alternative background sources to probe the Ly α forest in addition quasars, yielding high sightline densities that enable 3D tomographic reconstruction of foreground absorption field. Here, we present first data release from COSMOS Mapping And Tomography Observations (CLAMATO) Survey, which was conducted with LRIS spectrograph on Keck I telescope. Over an observational footprint 0.157 deg 2 within field, 240 and quasars 2.17...
Type Ia supernovae (SNe Ia) were instrumental in establishing the acceleration of universe's expansion. By virtue their combination distance reach, precision, and prevalence, they continue to provide key cosmological constraints, complementing other probes. Individual SN surveys cover only over about a factor two redshift, so compilations multiple datasets are strongly beneficial. We assemble an updated "Union" compilation 2087 cosmologically useful SNe from 24 ("Union3"). take care put all...
Big Bang Nucleosynthesis (BBN) is the synthesis of light nuclei, Deuterium (D or 2H), 3He, 4He and 7Li during first few minutes universe. This review concentrates on recent improvements in measurement primordial (after BBN, prior to modification) abundances these nuclei. We mention improvement standard theory, non-standard extensions which are limited by data.
Timmes, Brown & Truran found that metallicity variations could theoretically account for a 25% variation in the mass of 56Ni synthesized Type Ia supernovae (SNe Ia), and thus large fraction scatter observed SN luminosities. Higher-metallicity progenitors are more neutron-rich, producing stable burning products relative to radioactive 56Ni. We develop new method estimating bolometric luminosity yield SNe use it test theory with data from Supernova Legacy Survey. find average does drop high...
We present weak gravitational lensing analysis of 22 high-redshift (z >~1) clusters based on Hubble Space Telescope images. Most in our sample provide significant signals and are well detected their reconstructed two-dimensional mass maps. Combining the current results previous weak-lensing studies five other high-z clusters, we compare masses these with observables. revisit question whether presence most massive is tension LambdaCDM structure formation paradigm. find that tightly correlated...
We use Keck HIRES spectra of 37 optically bright quasars at z ¼ 2Y4 to study narrow absorption lines that are intrinsic the (intrinsic NALs, produced in gas is physically associated with quasar central engine).We identify 150 NAL systems, which contain 124 C iv, 12 N v, and 50 Si iv doublets, 18 systems (within 5000 km s À1 redshift).We partial coverage analysis separate NALs from cosmologically intervening structures.We find 39 candidate (28 reliable determinations 11 possibly intrinsic).We...