Spitzer IRAC infrared colours of submillimetre-bright galaxies

High-redshift submillimetre-bright galaxies identified by blank field surveys at millimetre and submillimetre wavelengths appear in the region of the Infra Red Array Camera (IRAC) colour–colour diagrams previously identified as the domain of luminous active galactic nuclei (AGNs). Our analysis using a set of empirical and theoretical dusty starburst spectral energy distribution (SED) models shows that power-law continuum sources associated with hot dust heated by young (≲100 Myr old), extreme starbursts at z > 2 also occupy the same general area as AGNs in the IRAC colour–colour plots. A detailed comparison of the IRAC colours and SEDs demonstrates that the two populations are distinct from each other, with submillimetre-bright galaxies having a systematically flatter IRAC spectrum (≳1 mag bluer in the observed [4.5]–[8.0] colour). Only about 20 per cent of the objects overlap in the colour–colour plots, and this low fraction suggests that submillimetre galaxies powered by a dust-obscured AGN are not common. The red infrared colours of the submillimetre galaxies are distinct from those of the ubiquitous foreground IRAC sources, and we propose a set of infrared colour selection criteria for identifying SMG counterparts that can be used even in the absence of radio or Multiband Imaging Photometer for Spitzer (MIPS) 24 μm data.     

Physicochemical characteristics for adsorption of MTBE and cadmium on clay minerals

Physicochemical characteristics relevant to the adsorption of MTBE and Cd on three types of clay minerals were investigated. The characteristics were examined through batch adsorption tests conducted under various experimental conditions such as adsorption time, ratio of solution-to soil, concentration of solutes, concentration of organic matters, pH, and zeta potential. The adsorption efficiency of MTBE or Cd on three types of clays decreased in response to an increase of the ratio of solution-to-soil; nevertheless, the adsorbed amounts inversely increased. MTBE was adsorbed on clays in an increasing order of vermiculite, bentonite, and CTAB-bentonite. However, Cd was adsorbed in a different order of bentonite, vermiculite, and CTAB-bentonite. The adsorption of MTBE was well fitted with the Freundlich model, whereas the Cd was more closely suited to a Langmuir equation. By adding humic acids of 1 and 5%, MTBE was significantly adsorbed on bentonite and vermiculite, respectively, but beyond that, its adsorption was diminished. In comparison, the adsorption on CTAB-bentonite was increased in proportion to the humic acids addition. Likewise, the addition of humic acids acted to increase the adsorption of Cd regardless of the types of adsorbent, where up to 90% of Cd was removed at pH 10. Further increase of pH declined the degree of zeta potential, while increasing Cd concentration also lowered the zeta potential, which consequently contributes in enhancing the adsorption efficiency of Cd on clays.     

Preliminary results of the multisite time-series campaign on the sdB pulsator PG 1325+101

I present a model for the formation and evolution of a massive disk galaxy, within a growing dark halo whose mass evolves according to cosmological simulations of structure formation. The galactic evolution is simulated with a new 3D chemo-dynamical code, including dark matter, stars and a multi-phase ISM. We follow the evolution from redshift z = 4.85 until the present epoch. The energy release by massive stars and supernovae prevents a rapid collapse of the baryonic matter and delays the maximum star formation until redshift z ≈ 1. The galaxy forms radially from inside-out and vertically from top-to-bottom. The feedback of stars leads to turbulent motions and large-scale flows in the ISM. As one result the galactic disk is significantly enriched by chemical elements synthesized in bulge stars.     

Methane on Uranus: The case for a compact CH4 cloud layer at low latitudes and a severe CH4 depletion at high-latitudes based on re-analysis of Voyager occultation measurements and STIS spectroscopy

Lindal et al. (Lindal, G.F., Lyons, J.R., Sweetnam, D.N., Eshleman, V.R., Hinson, D.P. [1987]. J. Geophys. Res. 92 (11), 14987-15001) presented a range of temperature and methane profiles for Uranus that were consistent with 1986 Voyager radio occultation measurements of refractivity versus altitude. A localized refractivity slope variation near 1.2 bars was interpreted to be the result of a condensed methane cloud layer. However, models fit to near-IR spectra found particle concentrations much deeper in the atmosphere, in the 1.5-3 bar range (Sromovsky, L.A., Irwin, P.G.J., Fry, P.M. [2006]. Icarus 182, 577-593; Sromovsky, L.A., Fry, P.M. [2010]. Icarus 210, 211-229; Irwin, P.G.J., Teanby, N.A., Davis, G.R. [2010]. Icarus 208, 913-926), and a recent analysis of STIS spectra argued for a model in which aerosol particles formed diffusely distributed hazes, with no compact condensation layer (Karkoschka, E., Tomasko, M. [2009]. Icarus 202, 287-309). To try to reconcile these results, we reanalyzed the occultation observations with the He volume mixing ratio reduced from 0.15 to 0.116, which is near the edge of the 0.033 uncertainty range given by Conrath et al. (Conrath, B., Hanel, R., Gautier, D., Marten, A., Lindal, G. [1987]. J. Geophys. Res. 92 (11), 15003-15010). This allowed us to obtain saturated mixing ratios within the putative cloud layer and to reach above-cloud and deep methane mixing ratios compatible with STIS spectral constraints. Using a 5-layer vertical aerosol model with two compact cloud layers in the 1-3 bar region, we find that the best fit pressure for the upper compact layer is virtually identical to the pressure range inferred from the occultation analysis for a methane mixing ratio near 4% at 5°S. This strongly argues that Uranus does indeed have a compact methane cloud layer. In addition, our cloud model can fit the latitudinal variations in spectra between 30°S and 20°N, using the same profiles of temperature and methane mixing ratio. But closer to the pole, the model fails to provide accurate fits without introducing an increasingly strong upper tropospheric depletion of methane at increased latitudes, in rough agreement with the trend identified by Karkoschka and Tomasko (Karkoschka, E., Tomasko, M. [2009]. Icarus 202, 287-309).     

A Correlation between Proton Events and Hα Flares and its Possible Interpretation

1 INTRoDUCTIONIt is well known that solar proton flares are maiuly correlated with strong, bright H. flares,in particular, with two ribbon flares. Ellison et al. (l961) were the first to draw attelltion tothe faCt that all cosndc-ray flares had the typical two-ribbon shape. Then, Svestka and Simon(1976) drew uP the "Catalog of Solar Particle Evellts, 195ty1969", and using this Catalog,Dodson and Hedeman could safely identify the flare sources for 50 proton events. Out of the 50idellti…     

Peculiarities of the abundance of chemical elements in the atmosphere of PMMR23-red supergiant in the Small Magellanic Cloud due to interstellar gas accretion

The chemical composition of the PMMR23 red supergiant located in the Small Magellanic Cloud (SMC) is analyzed. The abundance of 35 chemical elements and the upper limits of abundance for Tl and U are found. The relative abundance of heavy elements is higher by 0.6–1.0 dex with respect to iron peak elements. The spectra of several SMC red supergiants PMMR27, PMMR28, and PMMR144—located in the region where the velocities of stars and interstellar gas are quite high— show the emission components in the wings of the hydrogen line. This emission is not detected for PMMR23. A possibility of interstellar gas accretion on the atmospheres of PMMR23 and other supergiants in Magellanic Clouds is discussed. The analysis is carried out using spectra measured at ESO 3.6 m telescope with the spectral resolving power R = 30000.     

Basin-To-Basin and Year-To-Year Variation of Temperature and Salinity Characteristics in the East Sea (Sea of Japan)

Analysis of CTD data from four CREAMS expeditions carried out in summers of 1993–1996 produces distinct T-S relationships for the western and eastern Japan Basin, the Ulleung Basin and the Yamato Basin. T-S characteristics are mainly determined by salinity as it changes its horizontal pattern in three layers, which are divided by isotherms of 5°C and 1°C; upper warm water, intermediate water and deep cold water. Upper warm water is most saline in the Ulleung Basin and the Yamato Basin. Salinity of intermediate water is the highest in the eastern Japan Basin. Deep cold water has the highest salinity in the Japan Basin. T-S curves in the western Japan Basin are characterized by a salinity jump around 1.2–1.4°C in the T-S plane, which was previously found off the east coast of Korea associated with the East Sea Intermediate Water (Cho and Kim, 1994). T-S curves for the Japan Basin undergo a large year-to-year variation for water warmer than 0.6°C, which occupies upper 400 m. It is postulated that the year-to-year variation in the Japan Basin is caused by convective overturning in winter. This revised version was published online in August 2006 with corrections to the Cover Date.     

Spatial and seasonal variations in the water quality of Jinhae Bay,Korea

The chemical and biological characteristics of surface waters in Jinhae Bay were investigated over four seasons to understand water quality in light of the growing industrialisation occurring within this area. Jinhae Bay includes four smaller bays: Masan; Hangam; Jindong; and Gohyun. The water quality in Jinhae Bay varied spatially and seasonally. The water quality of both Hangam Bay and Masan Bay was highly degraded, demonstrating high concentrations of ammonia, nitrate, chlorophyll a and particulate organic carbon. Contamination from sewage was the dominant cause of the water quality deterioration in these bays. Conversely, the water quality in Jindong Bay and Gohyun Bay was not as severely affected as that of the above two bays. Water quality in Jinhae Bay was particularly poor in summer when nutrient loading was highest due to the run-off associated with high precipitation. Principal component analysis indicated that nitrogen contamination was a major factor influencing the water quality of Jinhae Bay. The effective reduction in high-nitrogen discharges is essential to improve water quality in Jinghae Bay.