Circumstellar structure of RU Lupi down to au scales

We have used the technique of spectro-astrometry to study the milliarcsecond scale structure of the emission lines in the T Tauri star RU Lupi. The wings of the H α emission are found to be displaced from the star towards the south-west (blue wing) and north-east (red wing) with angular scales of 20–30 mas. This structure is consistent with a bipolar outflow from the star. From a study of the variability of the intensity and position spectra, we argue that a combination of magnetically driven bipolar outflow and accreting gas contributes to the H α emission. On the other hand, the [O  i ] and [S  ii ] emission are displaced from the star to the south-west but at much larger distances than the H α , hundreds of milliarcseconds for the high-velocity component (HVC) and down to 30 mas for the low-velocity components (LVCs). The presence of both redshifted and blueshifted outflows in H α but only a blueshifted outflow in the forbidden lines can be explained if the disc obscures the redshifted forbidden line outflow, but a disc gap with outer radius 3–4 au allows the redshifted H α to be seen. This gap could be induced by an unseen companion.     

The Structure of Young Stellar Jets and Winds Revealed by High Resolution [Fe II] λ1.644μm Line Observations

We present high angular resolution spectra taken along the jets from L1551 IRS 5 and DG Tau obtained with the Subaru Telescope. The position-velocity diagrams of the [Fe II] λ 1.644 μmemission line revealed remarkably similar characteristics for the two sources, showing two distinct velocity components separated from each other in both velocity and space with the entire emission range blueshifted with respect to the stellar velocity. The high velocity component (HVC) has a velocity of –200 ––300 km s^-1 with a narrow line width, while the low velocity component (LVC) is around –100 km s^-1 exhibitinig a broad line width. The HVC is located farther away from the origin and is more extended than the LVC. Our results suggest that the HVC is a well-collimated jet originating from the region close to the star, while the LVC is a widely-opened wind accelerated in the region near the inner edge of the accretion disk.     

The comoving-frame equation of radiative transfer in relativistic flows

The comoving-frame equations of radiative transfer and moment equations to accurate terms of all orders inv/c are derived in the modified Lagrangian form. The equations exactly describe the interaction of radiation with matter in a relativistically moving medium in flat or curved spacetime. Two specialized sets of equations are presented: (1) the equation of radiative transfer and moment equations accurate to terms of second order (v ²/c ²), and (2) the transfer equation and moment equations for a radial flow in curved spacetime with the Schwarzschild-type metric.     

The heterotrophic activity for amino acids,glucose and acetate in Antarctic waters

The kinetic approach ofWright andHobbie (1966) was used to determine the heterotrophic potential of Antarctic waters. Variations with depth and geographical location are discussed. Temperature studies indicate the psychrophilic nature of the microbial population. In samples having environmental temperatures of approximately –1C, significant activities were recorded at the lowest incubation temperatures tested (–3C). Activities increased with increasing incubation temperatures up to +3C but were somewhat depressed at +10C and above. By testing a wide range of substrates, qualitative differences were noted in the microbial populations of different areas.Highest rates of uptake were found in the euphotic zone whereas V_max values of samples from depths of 500 m and below were in most cases unmeasurable.Published as Technical Paper No. 4259, Oregon Agricultural Experiment Station.     

A field study on the acute effects of the dispersant Corexit 9527 on glucose uptake by marine microorganisms

The effects of the dispersant Corexit 9527 and Corexit with crude oil on the rate of glucose uptake and mineralisation were studied in Arctic and Subarctic marine waters and sediments. Essentially all of the 149 water and 95 sediment samples tested displayed decreased glucose uptake rates in the presence of either 15 or 50 ppm Corexit. Depressed uptake rates were observed at concentrations as low as 1 ppm. The mean concentration at which Corexit depressed glucose uptake by 50% was 12 ppm. The effect of Corexit was more pronounced on pelagic than on benthic microbial populations.     

Thermolability of dehydrogenases from a psychrophilic marine bacterium

The heat lability of succinic dehydrogenase, malic dehydrogenase and lactate dehydrogenase in cell-free extracts ofVibrio marinus MP-1 grown at 15C was compared for the tris buffer suspended enzymes and the NaCl suspended enzymes. The tris buffer suspended enzymes lost 50 percent activity at low thermal exposure between 5C and 27C. No activity was evident on thermal exposure between 32C and 39C. The enzyme extracts suspended in NaCl at 36 % were more heat stable, losing 50 percent activity after exposure between 16C and 40C. The enzymes lost all activity on thermal exposure between 33C and 42C in the presence of NaCl.     

Differences in seasonality and temperature dependency of stand transpiration and canopy conductance between Japanese cypress (Hinoki) and Japanese cedar (Sugi) in a plantation

In this paper, we present an investigation of interspecies differences in transpiration of the 2 most common plantation forest tree species in Japan, both in the family Cupressaceae with different northern limits of native distribution, Japanese cypress (Hinoki; Chamaecyparis obtusa Sieb. et Zucc.) and Japanese cedar (Sugi; Cryptomeria japonica D. Don). The stem sap flow rate was measured in 2 nearby stands of similar leaf area index in a 42‐year‐old plantation. Single‐tree and stand‐scale transpiration rates (E_tre and E_sta, respectively) were observed during an ideal autumn environment. At the stand scale, mean sap flux density of Hinoki was greater than that of Sugi, whereas total sapwood area per ground area was smaller in Hinoki than Sugi. Because the 2 variables had counterbalancing effects on transpiration, E_sta of Hinoki was similar to (94% of) that of Sugi. This offset was also found between the mean E_tre of the 2 species. E_sta was similar between the stands from May to October, whereas E_sta of Sugi was notably greater than that of Hinoki from February to April. During these 3 months, the difference in cumulative E_sta was 21.7 mm, which accounted for 79% of the difference in annual E_sta between Hinoki and Sugi (192 and 219 mm/year, respectively). We found that canopy conductance (G_c) and its sensitivity to the mean vapour pressure deficit during daylight hours in Sugi were particularly high in early spring, whereas those in Hinoki shifted gradually throughout the growing season. This difference was related to the optimal temperature of G_c in Sugi, which was approximately 10 °C lower than that in Hinoki. Our results suggest that plantations of water‐conserving species such as Hinoki produce timber slowly but yield water resources generously. Moreover, for plantations of trees sensitive to high temperature, such as Sugi, managers should be concerned about possible future decline caused by anticipated global warming.     

The scalability of the accretion column in magnetic cataclysmic variables: the POLAR project

In this paper, theoretical and experimental laboratory astrophysics results are presented from the POLAR project, the main focus of which is to design and diagnose an exact scaled accretion column using powerful lasers. These measurements allow the testing of the astrophysical models of accretion processes present in magnetic cataclysmic variables.     

Analysis of rainfall characteristics of the Madden–Julian oscillation using TRMM satellite data

Rainfall characteristics of the Madden–Julian oscillation (MJO) are analyzed primarily using tropical rainfall measuring mission (TRMM) precipitation radar (PR), TRMM microwave imager (TMI) and lighting imaging sensor (LIS) data. Latent heating structure is also examined using latent heating data estimated with the spectral latent heating (SLH) algorithm.The zonal structure, time evolution, and characteristic stages of the MJO precipitation system are described. Stratiform rain fraction increases with the cloud activity, and the amplitude of stratiform rain variation associated with the MJO is larger than that of convective rain by a factor of 1.7. Maximum peaks of both convective rain and stratiform rain precede the minimum peak of the outgoing longwave radiation (OLR) anomaly which is often used as a proxy for the MJO convection. Stratiform rain remains longer than convective rain until 4000 km behind the peak of the mature phase. The stratiform rain contribution results in the top-heavy heating profile of the MJO.Associated with the MJO, there are tri-pole convective rain top heights (RTH) at 10–11, 7 and 3 km, corresponding to the dominance of afternoon showers, organized systems, and shallow convections, respectively. The stratiform rain is basically organized with convective rain, having similar but slightly lower RTH and slightly lags the convective rain maximum. It is notable that relatively moderate (7 km) RTH is dominant in the mature phase of the MJO, while very tall rainfall with RTH over 10 km and lightning frequency increase in the suppressed phase. The rain-yield-per flash (RPF) varies about 20–100% of the mean value of 2–10 × 10⁹ kg fl⁻¹ over the tropical warm ocean and that of 2–5 × 10⁹ kg fl⁻¹ over the equatorial Islands, between the convectively suppressed phase and the active phase of MJO, in the manner that RPF is smaller in the suppressed phase and larger in the active phase.     

Near-Infrared Colors of the Binary Kuiper Belt Object 1998 WW 31

We have measured near-infrared colorsof the binary Kuiper Belt object (KBO)1998 WW₃₁ using the Subaru Telescope withadaptive optics. The satellite was detectednear its perigee and apogee(0.18“ and 1.2” apart from the primary).The primary and the satellite have similar H–Kcolors, while the satellite is redder thanthe primary in J–H. Combined with the Rband magnitude previously published byVeillet et al., 2002, the color of the primaryis consistent with that of optically red KBOs. Thesatellite's R-, J-, H-colors suggest thepresence of ～1 μm absorption band dueto rock-forming minerals. If the surface of thesatellite is mainly composed by olivine, thesatellite's albedo is higher value than the canonicallyassumed value of 4%.