Results for "Akio K. Inoue"

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Competition between dust scattering albedo and 2175 A bump for ultraviolet colours of nearby disc galaxiesMay 06 2006Observed ultraviolet (UV) colours of nearby disc galaxies show a reddening relative to their expected intrinsic colours. Since the 2175 \AA bump found in the Milky Way's dust extinction law blues the UV colours, it might suggest that dust in nearby disc ... More
Star Formation Rate from Dust Infrared EmissionApr 13 2002We examine what types of galaxies the conversion formula from dust infrared (IR) luminosity into the star formation rate (SFR) derived by Kennicutt (1998) is applicable to. The ratio of the observed IR luminosity, $L_{\rm IR}$, to the intrinsic bolometric ... More
Spatial Distribution of Dust Grains within H II RegionsJan 22 2002We discuss the dust distribution within photoionized regions. Assuming a geometry with a central dust cavity, which is strongly suggested by the literature, we can estimate the cavity's radius from the ratio of the infrared and radio fluxes by using a ... More
Lyman Continuum Extinction by Dust in H {\sc ii} Regions of GalaxiesJun 28 2001We examine Lyman continuum extinction (LCE) in H II regions by comparing infrared fluxes of 49 H II regions in the Galaxy, M31, M33, and the LMC with estimated production rates of Lyman continuum photons. A typical fraction of Lyman continuum photons ... More
Lyman "bump" galaxies - I. Spectral energy distribution of galaxies with an escape of nebular Lyman continuumAug 27 2009Sep 18 2009It is essential to know galactic emissivity and spectrum of Lyman continuum (LyC) in order to understand the cosmic reionization. Here we consider an escape of nebular LyC from galaxies and examine the consequent spectral energy distribution. It is usually ... More
Constraint on intergalactic dust from thermal history of intergalactic mediumDec 06 2002Mar 13 2003This Letter investigates the amount of dust in the intergalactic medium (IGM). The dust photoelectric heating can be the most efficient heating mechanism in the IGM where the density is very small and there are a lot of hard ultraviolet photons. Comparing ... More
Star Formation Efficiency in the Central 1 kpc Region of Early-Type Spiral GalaxiesJul 20 2000It has been reported recently that there are some early-type spiral (Sa--Sab) galaxies having evident star-forming regions which concentrate in their own central 1-kpc. In such central region, is the mechanism of the star formation distinct from that ... More
Lyman continuum leaking AGN in the SSA22 fieldApr 01 2016Jun 17 2016Subaru/SuprimeCam narrowband photometry of the SSA22 field reveals the presence of four Lyman continuum (LyC) candidates among a sample of 14 AGN. Two show offsets and likely have stellar LyC in nature or are foreground contaminants. The remaining two ... More
Effect of Dust Extinction on Estimating Star Formation Rate of Galaxies: Lyman Continuum ExtinctionMar 15 2001We re-examine the effect of Lyman continuum ($\lambda \leq 912$ \AA) extinction (LCE) by dust in H {\sc ii} regions in detail and discuss how it affects the estimation of the global star formation rate (SFR) of galaxies. To clarify the first issue, we ... More
Effect of Photodesorption on Snow Line at the Surface of Optically Thick Circumstellar Disks around Herbig Ae/Be StarsJan 10 2012We investigate the effect of photodesorption on the snow line position at the surface of a protoplanetary disk around a Herbig Ae/Be star, motivated by the detection of water ice particles at the surface of the disk around HD142527 by Honda et al. For ... More
Searching for candidates of Lyman continuum sources - revisiting the SSA22 fieldSep 14 2015Oct 14 2016We present the largest to date sample of hydrogen Lyman continuum (LyC) emitting galaxy candidates at any redshift, with 18 Ly$\alpha$ Emitters (LAEs) and 7 Lyman Break Galaxies (LBGs), obtained from the SSA22 field with Subaru/Suprime-Cam. The sample ... More
Subaru narrow-band imaging search for Lyman continuum from galaxies at z>3 in the GOODS-N fieldJul 25 2019We report results of a search for galaxies at z>3 with Lyman continuum (LyC) emission using a narrow-band filter NB359 with Subaru / Suprime-Cam in a ~800 arcmin$^2$ blank field around the GOODS-N. We use 103 star-forming galaxies (SFGs) and 8 AGNs with ... More
Lyman `bump' galaxies - II. A possible signature of massive extremely metal-poor or metal-free stars in z=3.1 Ly-alpha emittersOct 13 2010(Abridged) Deep NB359 imaging with Subaru by Iwata et al. have detected surprisingly strong Lyman continuum (LyC; ~900A in the rest-frame) from some LAEs at z=3.1. However, the redshifts might be misidentified due to a narrow wavelength coverage in previous ... More
Cosmic Galaxy-IGM HI Relation at ${\it{z}}\sim 2-3$ Probed in the COSMOS/UltraVISTA $1.6$ deg$^2$ FieldMay 02 2016Nov 03 2016We present spatial correlations of galaxies and IGM neutral hydrogen HI in the COSMOS/UltraVISTA 1.62 deg$^2$ field. Our data consist of 13415 photo-$z$ galaxies at $z\sim2-3$ with $K_s<23.4$ and the Ly$\alpha$ forest absorptions in the background quasar ... More
A possible signature of primordial stellar populations in $z=3$ Lyman $α$ emittersJun 20 2012Observations with Subaru telescope have detected surprisingly strong Lyman continuum (LyC; $\sim900$ \AA\ in the rest-frame) from some Lyman $\alpha$ emitters (LAEs) at $z=3.1$. We have examined the stellar population which simultaneously accounts for ... More
Attenuation law of normal disc galaxies with clumpy distributions of stars and dustFeb 03 2005We investigate the attenuation law seen through an interstellar medium (ISM) with clumpy spatial distributions of stars and dust. The clumpiness of the dust distribution is introduced by a multi-phase ISM model. We solve a set of radiative transfer equations ... More
The origin of dust in galaxies revisited: the mechanism determining dust contentFeb 14 2012The origin of cosmic dust is a fundamental issue in planetary science. This paper revisits the origin of dust in galaxies, in particular, in the Milky Way, by using a chemical evolution model of a galaxy composed of stars, interstellar medium, metals ... More
Rest-frame ultraviolet-to-optical spectral characteristics of extremely metal-poor and metal-free galaxiesFeb 25 2011Apr 14 2011Finding the first generation of galaxies in the early Universe is the greatest step forward for understanding galaxy formation and evolution. For strategic survey of such galaxies and interpretation of the obtained data, this paper presents an ultraviolet-to-optical ... More
Evolution of Dust-to-Metal Ratio in GalaxiesAug 12 2003This paper investigates the evolution of the dust-to-metal ratio in galaxies based on a simple evolution model for the amount of metal and dust with infall. We take into account grain formation in stellar mass-loss gas, grain growth by the accretion of ... More
ADF22: Blind detections of [CII] line emitters shown to be spuriousJul 12 2019We report Atacama Large Millimetre/submillimeter Array (ALMA) Cycle-5 follow-up observations of two candidate [CII] emitters at z ~ 6 in the ALMA deep field in SSA22 (ADF22). The candidates were detected blindly in a Cycle-2 ALMA survey covering ~ 5 square ... More
The environments of Ly$α$ blobs I: Wide-field Ly$α$ imaging of TN J1338-1942, a powerful radio galaxy at $z\simeq 4.1$ associated with a giant Ly$α$ nebulaMar 24 2014Dec 03 2014We exploit wide-field Ly$alpha$ imaging with Subaru to probe the environment around TN J1338-1942, a powerful radio galaxy with a >100 kpc Ly$\alpha$ halo at z=4.11. We used a sample of Ly$\alpha$ emitters (LAEs) down to $\log(L_{\rm Ly\alpha} [erg\, ... More
A Monte Carlo simulation of the intergalactic absorption and the detectability of the Lyman continuum from distant galaxiesApr 18 2008We have made a Monte Carlo simulation of the intergalactic absorption in order to model the Lyman continuum absorption, which is required to estimate the escape fraction of the Lyman continuum from distant galaxies. To input into the simulation, we derive ... More
Intergalactic dust and its photoelectric heatingOct 31 2008We have examined the dust photoelectric heating in the intergalactic medium (IGM). The heating rate in a typical radiation field of the IGM is represented by $\Gamma_{\rm pe} = 1.2\times10^{-34}$ erg s$^{-1}$ cm$^{-3}$ $({\cal D}/10^{-4})(n_{\rm H}/10^{-5} ... More
Radiation-pressure-driven dust transport to galaxy halos at $z\sim 10$May 14 2019The origin of dust in galaxy halos or in the circum-galactic medium (CGM) is still a mystery. We investigate if the radiation pressure in high-redshift ($z\sim 10$) galaxies can efficiently transport dust to halos. To clarify the first dust enrichment ... More
Amount of intergalactic dust: constraints from distant supernovae and thermal history of intergalactic mediumOct 15 2003Jan 30 2004This paper examines the allowed amount of IG (intergalactic) dust, which is constrained by extinction and reddening of distant SNe and thermal history of IGM (intergalactic medium) affected by dust photoelectric heating. Based on the observational cosmic ... More
The Effect of the Remnant Mass in Estimating Stellar Mass of GalaxiesOct 03 2013The definition of the galactic stellar mass estimated from the spectral energy distribution is ambiguous in the literature; whether the stellar mass includes the mass of the stellar remnants, i.e. white dwarfs, neutron stars, and black holes, is not well ... More
Disentangling the physical parameters of gaseous nebulae and galaxiesDec 17 2018We present an analysis to disentangle the connection between physical quantities that characterize the conditions of ionized HII regions -- metallicity ($Z$), ionization parameter ($U$), and electron density ($n_\mathrm{e}$) -- and the global stellar ... More
"Big Three Dragons": a z = 7.15 Lyman BreakGalaxy Detected in [OIII] 88 $μ$m, [CII] 158 $μ$m, and Dust Continuum with ALMAJun 01 2018Apr 08 2019We present new ALMA observations and physical properties of a Lyman Break Galaxy at z=7.15. Our target, B14-65666, has a bright ultra-violet (UV) absolute magnitude, $M_{\rm UV}\approx-22.4$, and has been spectroscopically identified in Ly$\alpha$ with ... More
Lyman continuum observations across cosmic time: recent developments, future requirementsMay 27 2019Quantifying the physical conditions that allow radiation emitted shortward of the hydrogen ionization edge at 911.7 {\AA} to escape the first collapsed objects and ultimately reionize the universe is a compelling problem for astrophysics. The escape of ... More
Near-Infrared Colors of Gamma-Ray Burst Afterglows and Cosmic Reionization HistoryAug 12 2003Oct 06 2003Using the near-infrared (NIR) observations of the afterglows of the high redshift ($5 \la z \la 25$) gamma-ray bursts (GRBs) which will be detected by the {\it Swift} satellite, we discuss a way to study the cosmic reionization history. In principle the ... More
Star formation rate in galaxies from UV, IR, and H-alpha estimatorsAug 29 2003Infrared (IR) luminosity of galaxies originating from dust emission can be used as an indicator of the star formation rate (SFR). Inoue et al. (2000, IHK) have derived a formula for the conversion from IR luminosity to SFR by using the following three ... More
Effects of scattering and dust grain size on the temperature structure of protoplanetary discs: A three-layer approachDec 03 2008The temperature in the optically thick interior of protoplanetary discs is essential for the interpretation of millimeter observations of the discs, for the vertical structure of the discs, for models of the disc evolution and the planet formation, and ... More
SILVERRUSH. VII. Subaru/HSC Identifications of 42 Protocluster Candidates at z~6-7 with the Spectroscopic Redshifts up to z=6.574: Implications for Cosmic ReionizationJan 02 2018Jan 10 2018We report fourteen and twenty-eight protocluster candidates at z=5.7 and 6.6 over 14 and 19 deg^2 areas, respectively, selected from 2,230 (259) Lya emitters (LAEs) photometrically (spectroscopically) identified with Subaru/Hyper Suprime-Cam (HSC) deep ... More
The effect of radiation pressure on spatial distribution of dust inside HII regionsAug 23 2017Nov 20 2017We investigate the impact of radiation pressure on spatial dust distribution inside H$_\mathrm{II}$ regions using one-dimensional radiation hydrodynamic simulations, which include absorption and re-emission of photons by dust. In order to investigate ... More
Variability of Disk Emission in Pre-Main Sequence and Related Stars. III. Exploring Structural Changes in the Pre-transitional Disk in HD 169142Oct 31 2014We present near-IR and far-UV observations of the pre-transitional (gapped) disk in HD 169142 using NASA's Infrared Telescope Facility and Hubble Space Telescope. The combination of our data along with existing data sets into the broadband spectral energy ... More
The critical radiation intensity for direct collapse black hole formation: dependence on the radiation spectral shapeJul 15 2014It has been proposed that supermassive black holes (SMBHs) are originated from direct-collapse black holes (DCBHs) that are formed at z gtrsim 10 in the primordial gas in the case that H2 cooling is suppressed by strong external radiation. In this work, ... More
Detection of the Far-infrared [O III] and Dust Emission in a Galaxy at Redshift 8.312: Early Metal Enrichment in the Heart of the Reionization EraJun 11 2018Feb 11 2019We present the Atacama Large Millimeter/submillimeter Array (ALMA) detection of the [O III] 88 $\mu$m line and rest-frame 90 $\mu$m dust continuum emission in a Y-dropout Lyman break galaxy (LBG), MACS0416_Y1, lying behind the Frontier Field cluster MACS ... More
Revisiting the Cosmic Star Formation History: Caution on the Uncertainties in Dust Correction and Star Formation Rate ConversionAug 02 2012Jan 09 2013The cosmic star formation rate density (CSFRD) has been observationally investigated out to redshift z~10. However, most of theoretical models for galaxy formation underpredict the CSFRD at z>1. Since the theoretical models reproduce the observed luminosity ... More
A solvable quantum antiferromagnet modelAug 09 2005Aug 10 2005We introduce a quantum antiferromagnet model, having exactly soluble thermodynamic properties. It is an infinite range antiferromagnetic Ising model put in a transverse field. The free energy gives the ground state energy in the zero temperature limit ... More
Ribbonness of a stable-ribbon surface-link, I. A stably trivial surface-linkApr 08 2018Jun 19 2018There is a question asking whether a handle-irreducible summand of every stable-ribbon surface-link is a unique ribbon surface-link. This question is positively answered for the case of a stably trivial surface-link. That is, a handle-irreducible summand ... More
On a Morelli type expression of cohomology classes of toric varietiesJul 13 2010Let $X$ be a complete $\Q$-factorial toric variety of dimension $n$ and $\del$ the fan in a lattice $N$ associated to $X$. For each cone $\sigma$ of $\del$ there corresponds an orbit closure $V(\sigma)$ of the action of complex torus on $X$. The homology ... More
Unique diagram of a spatial arc and the knotting probabilityJul 24 2019It is shown that the projection image of an oriented spatial arc to any oriented plane is approximated by a unique arc diagram (up to isomorphic arc diagrams) determined from the spatial arc and the projection. In a separated paper, the knotting probability ... More
Invariance property of orbifold elliptic genus for multi-fansNov 28 2007Multi-fan is an analogous notion of fan. As a fan is associated to a toric variety a multi-fan is associated to a torus orbifold. Orbifold elliptic class and orbifold elliptic genus are defined for a triple of a multi-fan, a set of generating integral ... More
Ribbonness of a stable-ribbon surface-link, II. General caseJul 23 2019It is shown that a handle-irreducible summand of every stable-ribbon surface-link is a unique ribbon surface-link up to equivalences. This is a generalization of the result for the case of a stably trivial surface-link previously observed.
Escape fraction of ionizing photons from galaxies at z=0--6May 20 2006The escape fraction of ionizing photons from galaxies is a crucial quantity controlling the cosmic ionizing background radiation and the reionization. Various estimates of this parameter can be obtained in the redshift range, z=0--6, either from direct ... More
Observational Possibility of the "Snow Line" on the Surface of Circumstellar Disks with the Scattered LightFeb 07 2008We discuss how we obtain the spatial distribution of ice on the surface of the circumstellar disk around young stars. Ice in the disks plays a very important role in various issues, for instance, on the disk structure, on the planet formation, on the ... More
An updated analytic model for the attenuation by the intergalactic mediumFeb 04 2014May 12 2014We present an updated version of the so-called Madau model for the attenuation by the intergalactic neutral hydrogen against the radiation from distant objects. First, we derive a distribution function of the intergalactic absorbers from the latest observational ... More
Nebular line emission from z > 7 galaxies in cosmological simulations: rest-frame UV to Optical linesSep 02 2015Jun 11 2016We have performed very large and high resolution cosmological hydrodynamic simulations in order to investigate detectability of nebular lines in the rest-frame ultraviolet (UV) to optical wavelength range from galaxies at $z > 7$. We find that the expected ... More
Physical Properties of UDF12 Galaxies in Cosmological simulationsOct 01 2013Jan 15 2014We have performed a large cosmological hydrodynamics simulation tailored to the deep survey with the Hubble Space Telescope made in 2012, the so-called UDF12 campaign. After making a light-cone output, we have applied the same color selection criteria ... More
Emission from Dust in Galaxies: Metallicity DependenceNov 13 2000Infrared (IR) dust emission from galaxies is frequently used as an indicator of star formation rate (SFR). However, the effect of the dust-to-gas ratio (i.e., amount of the dust) on the conversion law from IR luminosity to SFR has not so far been considered. ... More
Inequality measures in kinetic exchange models of wealth distributionsSep 09 2015Feb 01 2016In this paper, we study the inequality indices for some models of wealth exchange. We calculated Gini index and newly introduced k-index and compare the results with reported empirical data available for different countries. We have found lower and upper ... More
Measuring social inequality with quantitative methodology: analytical estimates and empirical data analysis by Gini and $k$ indicesJun 11 2014Social inequality manifested across different strata of human existence can be quantified in several ways. Here we compute non-entropic measures of inequality such as Lorenz curve, Gini index and the recently introduced $k$ index analytically from known ... More
A Novel Quantum Transition in a Fully Frustrated Transverse Ising AntiferromagnetMay 28 2008Sep 11 2008We consider a long-range Ising antiferromagnet (LRIAF) put in a transverse field. Applying quantum Monte Carlo method, we study the variation of order parameter (spin correlation in Trotter time direction), susceptibility and average energy of the system ... More
Cyclic covers and Ihara's QuestionMar 22 2018Let $\ell$ be a rational prime and $k$ a number field. Given a superelliptic curve $C/k$ of $\ell$-power degree, we describe the field generated by the $\ell$-power torsion of the Jacobian variety in terms of the branch set and reduction type of $C$ (and ... More
Hawking radiation from a collapsing dust sphere and its back reaction at the event horizon -Weak value approach-May 01 2012Mar 16 2013To see the back reaction of the Hawking radiation in a dynamical spacetime of the spherical gravitational collapse, we explicitly calculate the weak value of the energy-momentum tensor of the massless scalar field. The background geometry of a collapsing ... More
Weak Values as Context Dependent Values of Observables and Born's RuleApr 11 2011Sep 08 2011We characterize a value of an observable by a `sum rule' for generally non-commuting observables and a `product rule' when restricted to a maximal commuting subalgebra of observables together with the requirement that the value is unity for the projection ... More
Simple Photoelectric Absorption during Dipping in the ASCA Observation of XB1916-053Aug 01 1997We report results of analysis of the ASCA observation of the Low Mass X-ray Binary dipping source XB1916-053 made on 1993, May 2nd. We have shown that the spectra can be well fitted by the same two-component model previously used to give good explanations ... More
Specific Heat Study of an S=1/2 Alternating Heisenberg Chain System F_5PNN Under Magnetic FieldSep 08 2004Dec 21 2004We have measured the specific heat of an S=1/2 antiferromagnetic alternating Heisenberg chain pentafulorophenyl nitronyl nitroxide under magnetic fields up to H>H_C2. This compound has the field-induced magnetic ordered (FIMO) phase between H_C1 and H_C2. ... More
ALMA will determine the spectroscopic redshift z>8 with FIR [O III] emission linesDec 03 2013We investigate the potential use of nebular emission lines in the rest-frame far-infrared (FIR) for determining spectroscopic redshift of z>8 galaxies with the Atacama Large Millimeter/sub-millimeter Array (ALMA). After making a line emissivity model ... More
Detections of [OIII] 88 $μ$m in Two Quasars in the Reionization EpochOct 31 2018Aug 04 2019With the Atacama Large Millimeter/sub-millimeter Array (ALMA), we report detections of the far-infrared (FIR) [OIII] 88 $\mu$m line and the underlying dust continuum in the two quasars in the reionization epoch, J205406.48-000514.8 (hereafter J2054-0005) ... More
Dust formation history of galaxies: a critical role of metallicity for the dust mass growth by accreting materials in the interstellar mediumJun 05 2012This paper investigate what is the main driver of the dust mass growth in the interstellar medium (ISM) by using a chemical evolution model of galaxy with metals (elements heavier than helium) in dust phase in addition to the total amount of metals. We ... More
Effects of dust scattering albedo and 2175 A bump on ultraviolet colours of normal disc galaxiesMay 06 2006We discuss dust properties in the interstellar medium (ISM) of nearby normal galaxies, by comparing observations in the ultraviolet (UV) with simulations by a radiative transfer model. The observed UV colours of nearby galaxies show a reddening relative ... More
Reexamination of the Infrared Excess-Ultraviolet Slope Relation of Local GalaxiesJun 18 2012The relation between the ratio of infrared (IR) and ultraviolet (UV) flux densities (the infrared excess: IRX) and the slope of the UV spectrum (\beta) of galaxies plays a fundamental role in the evaluation of the dust attenuation of star forming galaxies ... More
Primordial star clusters at extreme magnificationNov 24 2014Mar 10 2015Gravitationally lensed galaxies with magnification ~10-100 are routinely detected at high redshifts, but magnifications significantly higher than this are hampered by a combination of low probability and large source sizes. Magnifications of ~1000 may ... More
Detections of [OIII] 88 $μ$m in Two Quasars in the Reionization EpochOct 31 2018With the Atacama Large Millimeter/sub-millimeter Array (ALMA), we report detections of the far-infrared (FIR) [OIII] 88 $\mu$m line and the underlying dust continuum in the two quasars in the reionization epoch, J205406.48-000514.8 (hereafter J2054-0005) ... More
Remarks on elementary integral calculus for supersmooth functions on superspace ${\mathfrak{R}}^{m|n}$Aug 18 2014After introducing Berezin integral for polynomials of odd variables, we develop the elementary integral calculus based on supersmooth functions on the superspace ${\mathfrak{R}}^{m|n}$. Here, ${\mathfrak{R}}$ is the Fr\'echet-Grassmann algebra with countably ... More
Lectures on Super Analysis -- Why necessary and What's that?Apr 13 2015Dec 15 2015Roughly speaking, RA(=real analysis) means to study properties of (smooth) functions defined on real space, and CA(=complex analysis) stands for studying properties of (holomorphic) functions defined on spaces with complex structure. But to treat boson ... More
On positive and almost alternating linksOct 12 2015In this paper, we show that a link which has a positive and almost alternating diagram is alternating, besides that a positive and non-alternating Montesinos link has an almost positive-alternating diagram.
The 825 Smallest Right-Angled Hyperbolic PolyhedraDec 06 2015An algorithm for determining the list of smallest volume right-angled hyperbolic polyhedra in dimension 3 is described. This algorithm has been implemented on computer using the program Orb to compute volumes, and the first 825 polyhedra in the list have ... More
Field Effect Transistor Based on KTaO3 PerovskiteDec 12 2003An n-channel accumulation-type field effect transistor (FET) has been fabricated utilizing a KTaO3 single crystal as an active element and a sputtered amorphous Al2O3 film as a gate insulator. The device demonstrated an ON/OFF ratio of 10^4 and a field ... More
On the knot quandle of a fibered knot, finiteness and equivalence of knot quandlesJul 24 2018We show that the structure of a fibered knot, as a fiber bundle, is reflected in its knot quandle. As an application, we discuss finiteness and equivalence of knot quandles of concrete fibered 2-knots.
On colorability of knots by rotations, Torus knot and PL trochoidOct 10 2014The set consisting of all rotations of the Euclidean plane is equipped with a quandle structure. We show that a knot is colorable by this quandle if and only if its Alexander polynomial has a root on the unit circle in $\mathbb{C}$. Further we enumerate ... More
Quasi-triviality of quandles for link-homotopyMay 26 2012We introduce the notion of quasi-triviality of quandles and define homology of quasi-trivial quandles. Quandle cocycle invariants are invariant under link-homotopy if they are associated with 2-cocycles of quasi-trivial quandles. We thus obtain a lot ... More
Discovery of a Damped Lya Absorber at z = 3.3 along a galaxy sight-line in the SSA22 fieldDec 15 2015Jan 31 2016Using galaxies as background light sources to map the Lya absorption lines is a novel approach to study Damped Lya Absorbers (DLAs). We report the discovery of an intervening z = 3.335 +- 0.007 DLA along a galaxy sight-line identified among 80 Lyman Break ... More
Field-Effect Transistor on SrTiO3 with sputtered Al2O3 Gate InsulatorJun 17 2003A field-effect transistor that employs a perovskite-type SrTiO3 single crystal as the semiconducting channel is revealed to function as n-type accumulation-mode device with characteristics similar to that of organic FET's. The device was fabricated at ... More
Nonlinear Force-Free Extrapolation of the Coronal Magnetic Field Based on the MHD Relaxation MethodNov 14 2013We develop a nonlinear force-free field (NLFFF) extrapolation code based on the magnetohydrodynamic (MHD) relaxation method. We extend the classical MHD relaxation method in two important ways. First, we introduce an algorithm initially proposed by cite{2002JCoPh.175..645D} ... More
Possible Magnetic Chirality in Optically Chiral Magnet [Cr(CN)$_6$][Mn($S$)-pnH(H$_2$O)](H$_2$O) Probed by Muon Spin Rotation and RelaxationMar 01 2006Local magnetic fields in a molecule-based optically chiral magnet [Cr(CN)$_6$][Mn($S$)-pnH(H$_2$O)](H$_2$O) (GN-S) and its enantiomer (GN-R) are studied by means of muon spin rotation and relaxation (muSR). Detailed analysis of muon precession signals ... More
Imaging of diffuse HI absorption structure in the SSA22 proto-cluster region at z = 3.1Jan 10 2017Using galaxies as background light sources to map intervening Lya absorption is a novel approach to study the interplay among galaxies, the circum-galactic medium (CGM), and the intergalactic medium (IGM). Introducing a new measure of z = 3.1$ HI Lya ... More
A Hard Ionizing Spectrum in z=3-4 Ly-alpha Emitters with Intense [OIII] Emission: Analogs of Galaxies in the Reionization Era?Aug 29 2016Sep 22 2016We present Keck/MOSFIRE spectra of the diagnostic nebular emission lines [OIII]5007,4959, [OII]3727, and H-beta for a sample of 15 redshift z=3.1-3.7 Ly-alpha emitters (LAEs) and Lyman break galaxies (LBGs). In conjunction with spectra from other surveys, ... More
Japanese Cosmic Dawn/Epoch of Reionization Science with the Square Kilometre ArrayMar 07 2016Cosmic reionization is known to be a major phase transition of the gas in the Universe. Since astronomical objects formed in the early Universe, such as the first stars, galaxies and black holes, are expected to have caused cosmic reionization, the formation ... More
Enhancement of HI absorption associated with the $z=3.1$ large-scale proto-cluster and characteristic structures with AGNs sculptured over Gpc scale in the SSA22 fieldJan 31 2019In the SSA22 field which exhibits a large-scale proto-cluster at $z=3.1$, we carried out a spectroscopic survey for Lyman Break Galaxies (LBGs) with the VLT/VIMOS and identified 78 confident LBGs at $z=2.5$--4. We stacked their spectra in the observer's ... More
Kamland ResultsJul 15 2003The LMA solution of the solar neutrino problem has been explored with the 1,000 ton liquid scinatillator detector, KamLAND. It utilizes nuclear power reactors distributing effectively 180km from the experimental site. Comparing observed neutrino rate ... More
Intermediate psuedoscalar resonance contributions to B->X_s photon photonAug 14 1997We calculate the decay rate B-> X_s photon photon via intermediate psuedoscalar charmonium eta_c. This process is thought to be the main long-distance contribution which dominates the corresponding inclusive rare B decay. We point out that once the momentum ... More
Schroedinger wave operators on the discrete half-lineJul 07 2019An explicit formula for the wave operators associated with Schroedinger operators on the discrete half-line is deduced from their stationary expressions. The formula enables us to understand the wave operators as one dimensional pseudo-differential operators ... More
Characterization of Logic Program Revision as an Extension of Propositional RevisionJun 30 2015We address the problem of belief revision of logic programs, i.e., how to incorporate to a logic program P a new logic program Q. Based on the structure of SE interpretations, Delgrande et al. adapted the well-known AGM framework to logic program (LP) ... More
Strong CP Problem and the Natural Hierarchy of Yukawa CouplingsJun 02 2008Aug 20 2008A possible solution to the strong CP problem is presented without using an axion. The model is based on the framework of the supersymmetric vectorlike theory with the spontaneous breakdown of the P-C-T-invariance. It is shown that the characteristic structure ... More
Neutrino Physics around MeV EnergiesDec 25 2006We present a brief informative overview of a broad ranges of subjects, the solar, the reactor, the geo and the supernova neutrinos (but without excluding possible biases), the topics which consist of the session ``Neutrino Physics around MeV Energies'' ... More
Weak Lensing by Minifilament or Minivoid as the Origin of Flux-ratio Anomalies in Lensed Quasar MG0414+0534Oct 04 2014Dec 14 2014We explore the weak lensing effects by ministructures in the line-of-sight in a quadruply lensed quasar MG0414+0534 that shows an anomaly in the flux-ratios. We find that the observed flux-ratio anomaly can be explained by a presence of either a minifilament ... More
Charged lepton and down-type quark masses in SU(1,1) model and the structure of higgs sectorDec 18 2007Mar 04 2008The simplest noncompact group SU(1,1),when introduced as a symmetry group of the generations of quarks and leptons in the framework of a vector-like theory, gives an excellent viewpoint on low energy physics. The minimal setup of the scheme, however, ... More
Numerical Study of Length Spectra and Low-lying Eigenvalue Spectra of Compact Hyperbolic 3-manifoldsNov 09 2000Nov 14 2000In this paper, we numerically investigate the length spectra and the low-lying eigenvalue spectra of the Laplace-Beltrami operator for a large number of small compact(closed) hyperbolic (CH) 3-manifolds. The first non-zero eigenvalues have been successfully ... More
Geometric Gaussianity and Non-Gaussianity in the Cosmic Microwave BackgroundFeb 14 2000Feb 21 2000In this paper, Gaussianity of eigenmodes and non-Gaussianity in the Cosmic Microwave Background (CMB) temperature fluctuations in two smallest compact hyperbolic (CH) models are investigated. First, it is numerically found that the expansion coefficients ... More
Quantum secret sharing based on modulated high-dimensional time-bin entanglementJun 23 2006We propose a new scheme for quantum secret sharing (QSS) that uses a modulated high-dimensional time-bin entanglement. By modulating the relative phase randomly by {0,pi}, a sender with the entanglement source can randomly change the sign of the correlation ... More
Generation of polarization entangled photon pairs and violation of Bell's inequality using spontaneous four-wave mixing in fiber loopAug 05 2004We report the generation of polarization entangled photon pairs in the 1550-nm wavelength band using spontaneous four-wave mixing in a dispersion-shifted fiber loop. The use of the fiber-loop configuration made it possible to generate polarization entangled ... More
A Type System for First-Class Layers with Inheritance, Subtyping, and SwappingMay 04 2019Context-Oriented Programming (COP) is a programming paradigm to encourage modularization of context-dependent software. Key features of COP are layers---modules to describe context-dependent behavioral variations of a software system---and their dynamic ... More
The Transformation-Groupoid Structure of the q-Gaussian FamilyJan 16 2013The q-Gaussian function emerges naturally in various applications of statistical mechanics of non-ergodic and complex systems. In particular it was shown that in the theory of binary processes with correlations, the q-Gaussian can appear as a limiting ... More
Multi-Hamiltonian Structures on Beauville's Integrable System and Its VariantOct 20 2006Jan 09 2007We study Beauville's completely integrable system and its variant from a viewpoint of multi-Hamiltonian structures. We also relate our result to the previously known Poisson structures on the Mumford system and the even Mumford system.
Exotic radiation from a photonic crystal excited by an ultra-relativistic electron beamApr 27 2006We report the observation of an exotic radiation (unconventional Smith-Purcell radiation) from a one-dimensional photonic crystal. The physical origin of the exotic radiation is direct excitation of the photonic bands by an ultra-relativistic electron ... More
Detections of Lyman Continuum from Star-forming Galaxies at z~3 Through Subaru/Suprime-Cam Narrow-band ImagingMay 26 2008Feb 25 2009Knowing the amount of ionizing photons from young star-forming galaxies is of particular importance to understanding the reionization process. Here we report initial results of Subaru/Suprime-Cam deep imaging observation of the SSA22 proto-cluster region ... More
The distribution and physical properties of high-redshift [OIII] emitters in a cosmological hydrodynamics simulationMay 18 2018Sep 04 2018Recent observations with the Atacama Large Millimeter/submillimeter Array (ALMA) detected far-infrared emission lines such as the [OIII] 88 \mu m line from galaxies at $z \sim 7 - 9$. Far-infrared lines can be used to probe the structure and kinematics ... More
Fragmentation of star-forming clouds enriched with the first dustMar 28 2006The thermal and fragmentation properties of star-forming clouds have important consequences on the corresponding characteristic stellar mass. The initial composition of the gas within these clouds is a record of the nucleosynthetic products of previous ... More