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We use the Subaru Hyper Suprime-Cam (HSC) data to study structural parameters and systemic proper motion of the Sextans dwarf spheroidal galaxy at the heliocentric distance of 86 kpc, which is one of the most important targets for studies of dark matter nature and galaxy formation physics. Thanks to the superb image quality and wide area coverage, the HSC data enable a secure selection of member star candidates based on the colour–magnitude cut, yielding about 10 000 member candidates at magnitudes down to i ∼ 24. We use a likelihood analysis of the two-dimensional distribution of stars to estimate the structural parameters of Sextans taking into account the contamination of foreground halo stars in the Milky Way, and find that the member star distribution is well fitted by an elliptical King profile with ellipticity ϵ ≃ 0.25 and the core and tidal radii of R c = (368.4 ± 8.5) pc and R t = (2.54 ± 0.046) kpc, respectively. Then using the two HSC data sets of 2.66 yr time baseline on average, we find the systemic proper motions of Sextans to be (μα, μδ) = (−0.448 ± 0.075, 0.058 ± 0.078) mas yr−1, which are consistent with some of the previous works using the Gaia data of relatively bright member stars in Sextans. Thus, our results give a demonstration that ground-based, large-aperture telescope data that cover a wide solid angle of the sky and have a long time baseline, such as the upcoming data from Legacy Survey of Space and Time (LSST), can be used to study systemic proper motions of dwarf galaxies. [ABSTRACT FROM AUTHOR]

Author(s): Ji-an Jiang (corresponding author) [1, 2]; Mamoru Doi [1, 3, 4]; Keiichi Maeda [3, 5]; Toshikazu Shigeyama [4]; Kenichi Nomoto [3]; Naoki Yasuda [3]; Saurabh W. Jha [6]; Masaomi [...]

Disposal of oil sands tailings in ponds is a common method used by oil sands operators to manage the large volume of tailings generated from oil sands mining. This study considered a large tailings pond with an 11 km long ring dyke that was constructed of permeable tailings sand and equipped with drains and seepage collection ditches designed to collect process-affected water (PAW) from the dyke. The effectiveness of this seepage collection system was examined at the downgradient end of the tailings pond and dyke system using a focussed field investigation supported by groundwater flow modelling. A network of piezometers and drive points were installed in a 1 [km.sup.2] area to facilitate hydraulic measurements and water sampling to characterize the surface water and groundwater flow system. Chemical tracers suggest migration of PAW in a shallow, permeable sand deposit beyond an inner seepage collection ditch, but elevated hydraulic heads beyond the outer ditch have prevented further migration. A groundwater flow model was used to simulate the observed hydraulic dyke conditions and estimate the amount of PAW discharging into the shallow aquifer in the study area. Under the present hydraulic conditions, the seepage collection system is currently working to effectively contain PAW. Key words: oil sands, tailing ponds, process-affected water, groundwater, isotopes. Resume : La gestion des residus des operations de sables bitumineux implique habituellement la deposition de volumes importants de residus dans des parcs a residus. Cette etude s'est pencheee sur un grand parc a residus avec une digue de 11 km ceinturant le parc. Cette digue a ete construite avec des residus sablonneux permeeables, et eequipee de drains et de fosses concus dans le but de recolter l'eau de procede qui est exfiltree de la digue. L'efficacite des systemes de collecte de l'eau d'exfiltration a ete examinee dans la partie a l'aval du systeme parc a residu et digue a l'aide d'une investigation de terrain specifique supportee par une modelisation de l'eecoulement souterrain. Un reseau de pieezometres et des pointes filtrantes ont ete installe sur une surface de 1 [km.sup.2] afin de permettre d'effectuer des mesures hydrauliques et d'eechantillonner l'eau pour caracteriser l'eau de surface et l'eau souterraine. Des essais par traceurs chimiques suggerent que l'eau de procede migre a travers un depot de sable poreux et peu profond en-decja du fosse interne de collecte des exfiltrations, mais que les charges hydrauliques elevees au- dela du fosse exteerieur previennent la migration de l'eau de procede plus loin. Un modele d'ecoulement de l'eau souterraine a ete utilise pour simuler les conditions hydrauliques observees pour la digue, et pour estimer la quantite d'eau de procede dechargeee dans l'aquifere peu profond dans la zone d'etude. Pour les conditions hydrauliques actuelles, le systeme de collecte des exfiltrations fonctionne efficacement pour contenir l'eau de procede. Mots-cles: sables bitumineux, parc a residus, eau de procede;, eau souterraine, isotopes. [Traduit par la Redaction], Introduction It is estimated that Canada has 175 billion barrels of crude oil in oil sands reserves and ranks second only to Saudi Arabia in global oil reserves (Radler 2005). [...]

Reliable techniques for extracting the gate dielectric layer thickness from capacitance-voltage (CV) characteristics are essential for manufacturing process quality control. Continued reduction of the dielectric layer thickness has brought about a need for new measurement procedures which can account for the direct tunneling currents through the gate insulator. We present a guideline for performing two-frequency CV analysis of sub-2 nm gate oxides and show that it is possible to extract the dielectric layer thickness with an error of less than 4%. We show that in order to achieve this level of accuracy, it is necessary to choose the measurement frequencies and the test device size so that the dissipation remains below 1.1 at least at one of the two measurement frequencies. Index Terms--Accuracy, CV anaylsis, dielectrics, dissipation, extraction, extraction guideline, two-frequency measurement, ULSI, ultrathin oxide.

A new I-V model for stress-induced leakage current is reported and compared with the experimental I-V properties. The quantitative model is a modification of the trap-assisted tunneling model, incorporating the energy relaxation of tunneling electrons. In the new model, the energy relaxation is viewed as the change in the energy level of traps prior to and after the captivity of electrons during two-step tunneling.

A new experimental method for investigating the transport characteristics of stress-induced leakage current (SILC) is presented. The quantum results of impact ionization for electrons involved in the SILC process are measured directly from the change in the source and gate currents of p-MOSFETs prior and after stressing. Experimental results show that the measured energy of electrons in the SILC process is lower by approximately 1.5 eV than that expected in the elastic tunneling process.

Experimental studies using metal-oxide-semiconductor transistors with very thin oxide thicknesses help determine the spatial distribution of trapped holes and the position of charged centroids in the insulating layer of SiO2 films. Samples with extremely thin oxide films exhibit significant hole trapping and majority of the trapped holes lie between 2-6-nanometer from the Si/SiO2 surface. The trapped holes are distributed in an exponentially decaying manner with respect to distance from the Si/SiO2 interface. The charge centroid exists at 3.2 nanometers from the Si/SiO2 interface.

* Objective.--To compare the reactogenicity and immune response to the Takeda acellular pertussis-component diphtheria-tetanus-pertussis (APDT) vaccine in children when immunization commenced at 2 months (group A) vs 3 months (group B) of age. Design.--Longitudinal, nonblinded, comparative study. Setting.--Pediatric well-child clinics. Participants.--Healthy 50- to 98-day-old infants. Results.--Good antibody responses to lymphocytosis-promoting factor, filamentous hemagglutinin, agglutinogens, and pertactin occurred in both age groups after both the third and fourth vaccine doses. Both young age and transplacentally acquired maternal antibody independently and together have a suppressive effect on the response to the four antigens in this APDT vaccine. However, these effects appear to be minor. Vaccine reactions were mild; group A children had slightly but not significantly higher rates than group B children. Conclusion.--The present US diphtheria and tetanus toxoids and pertussis vaccine immunization schedule should also be satisfactory with this acellular pertussis component vaccine. (AJDC 1992;146:1141-1147)

A novel carrier measurement technique for depleted silicon on insulator metal oxide semiconductor field effect transistors (MOSFET) is presented. Capable of predicting generation and recombination lifetimes from transient drain current behavior analysis, it obtains the carrier lifetime from the transient inversioncharge density, accumulation charge concentration and the electric field. Experiments on MOSFET's made of SIMOX substrate verified the process's validity.

A gravitational wave event, S190510g, which was classified as a binary-neutron-star coalescence at the time of preliminary alert, was detected by LIGO/Virgo collaboration on 2019 May 10. At 1.7 hours after the issue of its preliminary alert, we started a target-of-opportunity imaging observation in the Y band to search for its optical counterpart using the Hyper Suprime-Cam (HSC) on the Subaru Telescope. The observation covers a 118.8 deg2 sky area corresponding to |$11.6\%$| confidence in the localization skymap released in the preliminary alert and |$1.2\%$| in the updated skymap. We divided the observed area into two fields based on the availability of HSC reference images. For the fields with the HSC reference images, we applied an image subtraction technique; for the fields without the HSC reference images, we sought individual HSC images by matching a catalog of observed objects with the PS1 catalog. The search depth is 22.28 mag in the former method and the limit of search depth is 21.3 mag in the latter method. Subsequently, we performed visual inspection and obtained 83 candidates using the former method and 50 candidates using the latter method. Since we only have the one-day photometric data, we evaluated the probability of candidates being located inside the 3D skymap by estimating their distances with photometry of associated extended objects. We found three candidates are likely located inside the 3D skymap and concluded they could be a counterpart of S190510g, while most of the 133 candidates were likely to be supernovae because the number density of candidates was consistent with the expected number of supernova detections. By comparing our observational depth with a light-curve model of such a kilonova reproducing AT2017gfo, we show that early deep observations with the Subaru/HSC can capture the rising phase of the blue component of a kilonova at the estimated distance of S190510g (∼230 Mpc). [ABSTRACT FROM AUTHOR]

The advancement of technology has resulted in a rapid increase in supernova (SN) discoveries. The Subaru/Hyper Suprime-Cam (HSC) transient survey, conducted from fall 2016 through spring 2017, yielded 1824 SN candidates. This gave rise to the need for fast type classification for spectroscopic follow-up and prompted us to develop a machine learning algorithm using a deep neural network with highway layers. This algorithm is trained by actual observed cadence and filter combinations such that we can directly input the observed data array without any interpretation. We tested our model with a dataset from the LSST classification challenge (Deep Drilling Field). Our classifier scores an area under the curve (AUC) of 0.996 for binary classification (SN Ia or non-SN Ia) and 95.3% accuracy for three-class classification (SN Ia, SN Ibc, or SN II). Application of our binary classification to HSC transient data yields an AUC score of 0.925. With two weeks of HSC data since the first detection, this classifier achieves 78.1% accuracy for binary classification, and the accuracy increases to 84.2% with the full dataset. This paper discusses the potential use of machine learning for SN type classification purposes. [ABSTRACT FROM AUTHOR]

Degradation mechanism of stacked high-k gate dielectrics has been studied with metal-oxide-semiconductor capacitors having HfAlOX/SiO2 films of various thickness combinations. A large leakage current with a peaked shape, named as the low-voltage peak current (LVPC), has been observed in the low-voltage region even in the initial current–voltage characteristics. It has been shown that a main part of LVPC is the transient current component controlled by the process of hole injection to traps in the vicinity of the HfAlOX/SiO2 interface through the interfacial SiO2 layer. By the electrical stress, both the transient and the steady-state current components monotonically increase with time having different rates. Steady-state component has significantly larger rate than the transient component, and the same rate with the stress-induced leakage current (SILC) observed in the high-voltage region, indicating that the steady-state component of LVPC should be regarded as the SILC in the higher-voltage region extending down to the lower gate voltage region where the LVPC is observed. [ABSTRACT FROM AUTHOR]

Degradation mechanism of stacked high-k gate dielectrics is studied with metal-oxide-semiconductor capacitors having HfAlO(sub x)/SiO(sub 2) films of various thickness combinations. A large leakage current with a peaked shape, named as the low-voltage peak current (LVPC), is observed in the low-voltage region even in the initial current-voltage characteristics.

We study the faint stellar halo of isolated central galaxies, by stacking galaxy images in the HSC survey and accounting for the residual sky background sampled with random points. The surface brightness profiles in HSC r band are measured for a wide range of galaxy stellar masses (9.2 < log10 M ∗/M⊙ < 11.4) and out to 120 kpc. Failing to account for the stellar halo below the noise level of individual images will lead to underestimates of the total luminosity by ≤15%. Splitting galaxies according to the concentration parameter of their light distributions, we find that the surface brightness profiles of low-concentration galaxies drop faster between 20 and 100 kpc than those of high-concentration galaxies. Albeit the large galaxy-to-galaxy scatter, we find a strong self-similarity of the stellar halo profiles. They show unified forms once the projected distance is scaled by the halo virial radius. The colour of galaxies is redder in the centre and bluer outside, with high-concentration galaxies having redder and more flattened colour profiles. There are indications of a colour minimum, beyond which the colour of the outer stellar halo turns red again. This colour minimum, however, is very sensitive to the completeness in masking satellite galaxies. We also examine the effect of the extended PSF in the measurement of the stellar halo, which is particularly important for low-mass or low-concentration galaxies. The PSF-corrected surface brightness profile can be measured down to ∼31  |$\mathrm{mag}\, \mathrm{arcsec}^{-2}$| at 3σ significance. PSF also slightly flattens the measured colour profiles. [ABSTRACT FROM AUTHOR]

Deals with a study which investigated the positive charge and interface trap generation during substrate hot-hole injection into the insulating layer of a metal-oxide semiconductor structure. Preparation of the sample; Measurement and injection of hot-hole; Calculation of trapped hole density and injection fluence.

We present a measurement of the rate of high-z Type Ia supernovae (SNe Ia) using multi-epoch observations of Subaru/XMM-Newton Deep Field (SXDF) with Suprime-Cam on the Subaru Telescope. Although SNe Ia are regarded as a standard candle, progenitor systems of SNe Ia have not been resolved yet. One of the key parameters to show the progenitor systems by observations is the delay time distribution between the binary system formation and subsequent SN explosion. Recently, a wide range of delay time is studied by SN Ia rates compared with an assumed cosmic star formation history. If SNe Ia with short delay time are dominant, the cosmic SN Ia rate evolution should closely trace that of the cosmic star formation. In order to detect a lot of high-z SNe Ia and measure SN Ia rates, we repeatedly carried out wide and deep imaging observations in the í-band with Suprime-Cam in 2002 (FoV~1 deg2, mi < 25.5 mag). We obtained detailed light curves of the variable objects, and 50 objects are classified as SNe Ia using the light curve fitting method at the redshift range of 0.2 < z < 1.3. In order to check the completeness and contamination of the light curve classification method, we performed Monte Carlo simulations and generated ~100,000 light curves of SNe Ia and II from templates. The control time and detection efficiency of the SN survey are also calculated using the artificial light curves. We derived an increasing trend of rates at around z ~ 1.2. Our results are almost consistent with other SN Ia rate results from low-z to high-z. Our results are the first results of high-z SN Ia rates with large statistics using light curves obtained by ground based telescopes, and give us visions of the SN rate studies for the future. [ABSTRACT FROM PUBLISHER]

The Coma cluster is the richest and most compact of the nearby clusters, yet there is growing evidence that its formation is still on-going. A sensitive probe of this evolution is the dynamics of intracluster stars, which are unbound from galaxies while the cluster forms, according to cosmological simulations. With a new multi-slit imaging spectroscopy technique pioneered at the 8.2 m Subaru telescope and FOCAS, we can now detect and measure the line-of-sight velocities of the intracluster planetary nebulae which are associated with the diffuse stellar population of stars, at 100 Mpc distance. We detect significant velocity substructures within a 6 arcmin diameter field, centred on the Coma X-ray cluster emission. One substructure is present at $\sim $5000 km s$^{-1}$, probably from infall of a galaxy group, while the main intracluster stellar component moves at $\sim $6500 km s$^{-1}$. Hence the ICPNs associated with the diffuse light at the position of the MSIS field are not bound to the nearby cD galaxy NGC 4874, whose radial velocity is $\sim $700 km s$^{-1}$ higher. [ABSTRACT FROM PUBLISHER]

We report the discovery of a probable large-scale structure composed of many galaxy clumps around the known twin clusters atand 1.27 in the Lynx region. Our analysis is based on deep, panoramic, and multicolour imaging,inVRi′ z′ bands with the Suprime-Cam on the 8.2-m Subaru telescope. This unique, deep and wide-field imaging data set allows us for the first time to map out the galaxy distribution in the highest-redshift supercluster known. We apply a photometric redshift technique to extract plausible cluster members atdown tocorresponding toat this redshift. From the two-dimensional distribution of these photometrically selected galaxies, we newly identify seven candidates of galaxy groups or clusters where the surface density of red galaxies is significantly high (>5σ), in addition to the two known clusters. These candidates show clear red colour–magnitude sequences consistent with a passive evolution model, which suggests the existence of additional high-density regions around the Lynx superclusters. [ABSTRACT FROM AUTHOR]

We report the discovery of a probable large-scale structure composed of many galaxy clumps around the known twin clusters at $z=1.26$ and $z=1.27$ in the Lynx region. Our analysis is based on deep, panoramic, and multi-colour imaging with the Suprime-Cam on the 8.2 m Subaru telescope. We apply a photometric redshift technique to extract plausible cluster members at $z\sim1.27$ down to $\sim M^\ast+2.5$. From the 2-D distribution of these photometrically selected galaxies, we newly identify seven candidates of galaxy groups or clusters where the surface density of red galaxies is significantly high ($>$5$\sigma$), in addition to the two known clusters, comprising the largest most distant supercluster ever identified.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html [ABSTRACT FROM PUBLISHER]

Presents the I-V model for stress-induced leakage current (SILC). Modifications for the trap-assisted tunneling model; Analysis of trap distribution; Physical parameters utilized in the experiment.

We investigate pure luminosity evolution models for early-type (elliptical and S0) galaxies (i.e. no number density change or morphological transition), and examine whether these models are consistent with observed number counts in the B, I and K bands, and redshift distributions of two samples of faint galaxies selected in the I and K bands. The models are characterized by the star formation time-scale τ[sub SF] and the time t[sub gw] when the galactic wind starts to blow, in addition to several other conventional parameters. We find that the single-burst model (τ[sub SF]=0.1 Gyr and t[sub gw]=0.353 Gyr), which is known to reproduce the photometric properties of early-type galaxies in clusters, is inconsistent with the redshift distributions of early-type galaxies in the field environment, owing to overpredictions of the number of galaxies at z>=1.4 even with strong extinction which is at work until t[sub gw]. In order for dust extinction to be more effective, we treat τ[sub SF] and t[sub gw] as free parameters, and find that models with τ[sub SF]>=0.5 Gyr and t[sub gw]>1.0 Gyr can be made consistent with both the observed redshift distributions and the number counts, if we introduce strong extinction [E(B-V)≥1 as a peak value]. These results suggest that early-type galaxies in the field environment do not have the same evolutionary history as described by the single-burst model. [ABSTRACT FROM AUTHOR]

This paper describes the Third Data Release of the Sloan Digital Sky Survey (SDSS). This release, containing data taken up through 2003 June, includes imaging data in five bands over 5282 deg2, photometric and astrometric catalogs of the 141 million objects detected in these imaging data, and spectra of 528,640 objects selected over 4188 deg2. The pipelines analyzing both images and spectroscopy are unchanged from those used in our Second Data Release., Astronomy

The Sloan Digital Sky Survey (SDSS) has validated and made publicly available its Second Data Release. This data release consists of 3324 deg2 of five-band (ugriz) imaging data with photometry for over 88 million unique objects, 367,360 spectra of galaxies, quasars, stars, and calibrating blank sky patches selected over 2627 deg2 of this area, and tables of measured parameters from these data. The imaging data reach a depth of r ≈ 22.2 (95% completeness limit for point sources) and are photometrically and astrometrically calibrated to 2% rms and 100 mas rms per coordinate, respectively. The imaging data have all been processed through a new version of the SDSS imaging pipeline, in which the most important improvement since the last data release is fixing an error in the model fits to each object. The result is that model magnitudes are now a good proxy for point-spread function magnitudes for point sources, and Petrosian magnitudes for extended sources. The spectroscopy extends from 3800 to 9200 Å at a resolution of 2000. The spectroscopic software now repairs a systematic error in the radial velocities of certain types of stars and has substantially improved spectrophotometry. All data included in the SDSS Early Data Release and First Data Release are reprocessed with the improved pipelines and included in the Second Data Release. Further characteristics of the data are described, as are the data products themselves and the tools for accessing them., Astronomy

The Sloan Digital Sky Survey (SDSS) mosaic camera and telescope have obtained five-band optical-wavelength imaging near the Galactic plane outside of the nominal survey boundaries. These additional data were obtained during commissioning and subsequent testing of the SDSS observing system, and they provide unique wide-area imaging data in regions of high obscuration and star formation, including numerous young stellar objects, Herbig-Haro objects, and young star clusters. Because these data are outside the survey regions in the Galactic caps, they are not part of the standard SDSS data releases. This paper presents imaging data for 832 square degrees of sky (including repeats), in the star-forming regions of Orion, Taurus, and Cygnus. About 470 deg2 are now released to the public, with the remainder to follow at the time of SDSS Data Release 4. The public data in Orion include the star-forming region NGC 2068/NGC 2071/HH 24 and a large part of Barnard's loop., Astronomy

The Sloan Digital Sky Survey (SDSS) has validated and made publicly available its First Data Release. This consists of 2099 deg2 of five-band (u, g, r, i, z) imaging data, 186,240 spectra of galaxies, quasars, stars and calibrating blank sky patches selected over 1360 deg2 of this area, and tables of measured parameters from these data. The imaging data go to a depth of r ≈ 22.6 and are photometrically and astrometrically calibrated to 2% rms and 100 mas rms per coordinate, respectively. The spectra cover the range 3800–9200 Å, with a resolution of 1800–2100. This paper describes the characteristics of the data with emphasis on improvements since the release of commissioning data (the SDSS Early Data Release) and serves as a pointer to extensive published and on-line documentation of the survey., Astronomy

In the course of its commissioning observations, the Sloan Digital Sky Survey (SDSS) has produced one of the largest redshift samples of galaxies selected from CCD images. Using 11,275 galaxies complete to r* = 17.6 over 140 deg2, we compute the luminosity function of galaxies in the r* band over a range -23 < M < -16 (for h = 1). The result is well-described by a Schechter function with parameters phgr* = (1.46 ± 0.12) × 10-2 h3 Mpc-3, M* = -20.83 ± 0.03, and α = -1.20 ± 0.03. The implied luminosity density in r* is j ≈ (2.6 ± 0.3) × 108h L⊙ Mpc-3. We find that the surface brightness selection threshold has a negligible impact for M < -18. Using subsets of the data, we measure the luminosity function in the u*, g*, i*, and z* bands as well; the slope at low luminosities ranges from α = -1.35 to α = -1.2. We measure the bivariate distribution of r* luminosity with half-light surface brightness, intrinsic g*-r* color, and morphology. In agreement with previous studies, we find that high surface brightness, red, highly concentrated galaxies are on average more luminous than low surface brightness, blue, less concentrated galaxies. An important feature of the SDSS luminosity function is the use of Petrosian magnitudes, which measure a constant fraction of a galaxy's total light regardless of the amplitude of its surface brightness profile. If we synthesize results for RGKC band or bj band using these Petrosian magnitudes, we obtain luminosity densities 2 times that found by the Las Campanas Redshift Survey in RGKC and 1.4 times that found by the Two Degree Field Galaxy Redshift Survey in bj. However, we are able to reproduce the luminosity functions obtained by these surveys if we also mimic their isophotal limits for defining galaxy magnitudes, which are shallower and more redshift dependent than the Petrosian magnitudes used by the SDSS., Astronomy