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Context. Eta Carinae is a highly eccentric, massive binary system (semimajor axis ~15.5 au) with powerful stellar winds and a phase-dependent wind-wind collision (WWC) zone. The primary star, η Car A, is a luminous blue variable (LBV); the secondary, η Car B, is a Wolf-Rayet or O star with a faster but less dense wind. Aperture-synthesis imaging allows us to study the mass loss from the enigmatic LBV η Car. Understanding LBVs is a crucial step toward improving our knowledge about massive stars and their evolution. Aims. Our aim is to study the intensity distribution and kinematics of η Car’s WWC zone. Methods. Using the VLTI-MATISSE mid-infrared interferometry instrument, we perform Brα imaging of η Car’s distorted wind. Results. We present the first VLTI-MATISSE aperture-synthesis images of η Car A’s stellar windin several spectral channels distributed across the Brα 4.052 μm line (spectral resolving power R ~ 960). Our observations were performed close to periastron passage in February 2020 (orbital phase ~ 14.0022). The reconstructed iso-velocity images show the dependence of the primary stellar wind on wavelength or line-of-sight (LOS) velocity with a spatial resolution of 6 mas (~14 au). The radius of the faintest outer wind regions is ~26 mas (~60 au). At several negative LOS velocities, the primary stellar wind is less extended to the northwest than in other directions. This asymmetry is most likely caused by the WWC. Therefore, we see both the velocity field of the undisturbed primary wind and the WWC cavity. In continuum spectral channels, the primary star wind is more compact than in line channels. A fit of the observed continuum visibilities with the visibilities of a stellar wind CMFGEN model (CMFGEN is an atmosphere code developed to model the spectra of a variety of objects) provides a full width at half maximum fit diameter of the primary stellar wind of 2.84 ± 0.06 mas (6.54 ± 0.14 au). We comparethe derived intensity distributions with the CMFGEN stellar wind model and hydrodynamic WWC models.

Context: FS Canis Majoris (FS CMa, HD 45677) is an unclassified B[e] star surrounded by an inclined dust disk. The evolutionary stage of FS CMa is still debated. Perpendicular to the circumstellar disk, a bipolar outflow was detected. Infrared aperture-synthesis imaging provides us with a unique opportunity to study the disk structure. Aims: Our aim is to study the intensity distribution of the disk of FS CMa in the mid-infrared L and N bands. Methods: We performed aperture-synthesis imaging of FS CMa with the MATISSE instrument (Multi AperTure mid-Infrared SpectroScopic Experiment) in the low spectral resolution mode to obtain images in the L and N bands. We computed radiative transfer models that reproduce the L- and N-band intensity distributions of the resolved disks. Results: We present L- and N-band aperture-synthesis images of FS CMa reconstructed in the wavelength bands of 3.4-3.8 and 8.6-9.0 micrometer. In the L-band image, the inner rim region of an inclined circumstellar disk and the central object can be seen with a spatial resolution of 2.7 milliarcsec (mas). An inner disk cavity with an angular diameter of 6x12mas is resolved. The L-band disk consists of a bright northwestern (NW) disk region and a much fainter southeastern (SE) region. The images suggest that we are looking at the bright inner wall of the NW disk rim, which is on the far side of the disk. In the N band, only the bright NW disk region is seen. In addition to deriving the inclination and the inner disk radius, fitting the reconstructed brightness distributions via radiative transfer modeling allows one to constrain the innermost disk structure, in particular the shape of the inner disk rim., Comment: accepted for publication in A&A

Despite its importance on late stages of the evolution of massive stars, the mass loss from red supergiants (RSGs) is a long-standing problem. To tackle this problem, it is essential to observe the wind acceleration region close to the star with high spatial resolution. While the mass loss from RSGs is often assumed to be spherically symmetric with a monotonically accelerating wind, there is mounting observational evidence that the reality is much more complex. I review the recent progress in high spatial resolution observations of RSGs, encompassing from the circumstellar envelope on rather large spatial scales (~100 stellar radii) to milliarcsecond-resolution aperture-synthesis imaging of the surface and the atmosphere of RSGs with optical and infrared long-baseline interferometers.

Red supergiant stars represent a late stage of the evolution of stars more massive than about nine solar masses, in which they develop complex, multi-component atmospheres. Bright spots have been detected in the atmosphere of red supergiants using interferometric imaging. Above the photosphere of a red supergiant, the molecular outer atmosphere extends up to about two stellar radii. Furthermore, the hot chromosphere (5,000 to 8,000 kelvin) and cool gas (less than 3,500 kelvin) of a red supergiant coexist at about three stellar radii. The dynamics of such complex atmospheres has been probed by ultraviolet and optical spectroscopy. The most direct approach, however, is to measure the velocity of gas at each position over the image of stars as in observations of the Sun. Here we report the mapping of the velocity field over the surface and atmosphere of the nearby red supergiant Antares. The two-dimensional velocity field map obtained from our near-infrared spectro-interferometric imaging reveals vigorous upwelling and downdrafting motions of several huge gas clumps at velocities ranging from about -20 to +20 kilometres per second in the atmosphere, which extends out to about 1.7 stellar radii. Convection alone cannot explain the observed turbulent motions and atmospheric extension, suggesting that an unidentified process is operating in the extended atmosphere., Comment: 27 pages, 8 figures, published in Nature

We present a near-infrared spectro-interferometric observation of the non-Mira-type, semiregular asymptotic giant branch star SW Vir. Our aim is to probe the physical properties of the outer atmosphere with spatially resolved data in individual molecular and atomic lines. We observed SW Vir in the spectral window between 2.28 and 2.31 micron with the near-infrared interferometric instrument AMBER at ESO's Very Large Telescope Interferometer (VLTI). Thanks to AMBER's high spatial resolution and high spectral resolution of 12000, the atmosphere of SW Vir has been spatially resolved not only in strong CO first overtone lines but also in weak molecular and atomic lines of H2O, CN, HF, Ti, Fe, Mg, and Ca. Comparison with the MARCS photospheric models reveals that the star appears larger than predicted by the hydrostatic models not only in the CO lines but also even in the weak molecular and atomic lines. We found that this is primarily due to the H2O lines (but also possibly due to the HF and Ti lines) originating in the extended outer atmosphere. Although the H2O lines manifest themselves very little in the spatially unresolved spectrum, the individual rovibrational H2O lines from the outer atmosphere can be identified in the spectro-interferometric data. Our modeling suggests an H2O column density of 10^{19}--10^{20} cm^{-2} in the outer atmosphere extending out to ~2 Rstar. Our study has revealed that the effects of the nonphotospheric outer atmosphere are present in the spectro-interferometric data not only in the strong CO first overtone lines but also in the weak molecular and atomic lines. Therefore, analyses of spatially unresolved spectra, such as for example analyses of the chemical composition, should be carried out with care even if the lines appear to be weak., 8 pages, 6 figures, accepted for publication in Astronomy and Astrophysics

The outer atmosphere of K giants shows thermally inhomogeneous structures consisting of the hot chromospheric gas and the cool molecular gas. We present spectro-interferometric observations of the multicomponent outer atmosphere of the well-studied K1.5 giant Arcturus (alpha Boo) in the CO first overtone lines near 2.3 micron. We observed Arcturus with the AMBER instrument at the Very Large Telescope Interferometer (VLTI) at 2.28--2.31 micron with a spectral resolution of 12000 and at projected baselines of 7.3, 14.6, and 21.8 m. The high spectral resolution of the VLTI/AMBER instrument allowed us to spatially resolve Arcturus in the individual CO lines. Comparison of the observed interferometric data with the MARCS photospheric model shows that the star appears to be significantly larger than predicted by the model. It indicates the presence of an extended component that is not accounted for by the current photospheric models for this well-studied star. We found out that the observed AMBER data can be explained by a model with two additional CO layers above the photosphere. The inner CO layer is located just above the photosphere, at 1.04 +/- 0.02 stellar radii, with a temperature of 1600 +/- 400 K and a CO column density of 10^{20 +/- 0.3} cm^-2. On the other hand, the outer CO layer is found to be as extended as to 2.6 +/- 0.2 stellar radii with a temperature of 1800 +/- 100 K and a CO column density of 10^{19 +/- 0.15} cm^-2. The properties of the inner CO layer are in broad agreement with those previously inferred from the spatially unresolved spectroscopic analyses. However, our AMBER observations have revealed that the quasi-static cool molecular component extends out to 2--3 stellar radii, within which region the chromospheric wind steeply accelerates., 10 pages, 9 figures, accepted for publication in Astronomy and Astrophysics

The circumstellar environment of the AGB star L$_{\rm 2}$ Puppis was observed with ALMA in cycle 3, with a resolution of $15 \times 18 \rm\ mas$. The molecular emission shows a differentially rotating disk, inclined to a nearly edge-on position. In the first paper in this series (paper I) the molecular emission was analysed to accurately deduce the motion of the gas in the equatorial regions of the disk. In this work we model the optically thick $^{\rm 12}$CO $J=$3$-$2 and the optically thin $^{\rm 13}$CO $J=$3$-$2 rotational transition to constrain the physical conditions in the disk. To realise this effort we make use of the 3D NLTE radiative transfer code {\tt LIME}. The temperature structure and velocity structure show a high degree of complexity, both radially and vertically. The radial H$_{\rm 2}$ density profile in the disk plane is characterised by a power law with a slope of $-3.1$. We find a $^{\rm 12}$CO over $^{\rm 13}$CO abundance ratio of 10 inside the disk. Finally, estimations of the angular momentum in the disk surpass the expected available angular momentum of the star, strongly supporting the indirect detection of a compact binary companion reported in paper I. We estimate the mass of the companion to be around 1 Jupiter mass., 21 pages; 19 figures

We report measurements of cross sections and analyzing powers for nucleon-knockout $(\stackrel{P\vec}{p},np)$ reactions of $^{2}\mathrm{H}, ^{6}\mathrm{Li}$, and $^{12}\mathrm{C}$ at 296 MeV using the RCNP NPOL3 neutron detector and large acceptance spectrometer. The $1s$ and $1p$ knockout reactions were successfully separated with a separation-energy resolution of approximately 6 MeV. The resulting data were compared with plane-wave and distorted-wave impulse approximation calculations employing the nucleon-nucleon $t$ matrix in free space. No significant differences were identified in the case of the present analyzing power data, in contrast to the significant reductions observed in $(\stackrel{P\vec}{p},2p)$ values. The conventional Pauli blocking and nuclear binding effects with the $g$ matrix and the relativistic effect of nucleon mass reduction in the nuclei are also discussed.

Space Star (SS) anomaly in nd breakup cross section was first reported in 1989 at E n = 13 MeV (Strate et al. in Nucl Phys A 501:51, 1989), but its origin has not been found yet. In order to obtain suggestions for its origin, we made systematic measurements of pd breakup cross section around SS. In SS configuration, three outgoing nucleons form an equilateral triangle and the triangle is perpendicular to the beam axis. Necessity of the equilateral and perpendicular conditions of SS anomaly was investigated by systematic experiments. Also energy dependence of SS anomaly is being studied at energies from E p = 7.5 to 13 MeV.

Space Star (SS) anomalies in nd and pd breakup reactions below 20 MeV were reported since 1989, but their origin has not been found yet. We have considered two conditions for the SS anomalies : condition (a) where three outgoing nucleons form an equilateral triangle and condition (b) in which the triangle is perpendicular to the beam axis. The condition (b) was investigated by our previous systematic experiments on pd breakup. In the present study, we started systematic experiments for the condition (a).

We present visible polarimetric imaging observations of the well-studied AGB star W Hya taken with VLT/SPHERE-ZIMPOL as well as high spectral resolution long-baseline interferometric observations with the AMBER instrument of the Very Large Telescope Interferometer (VLTI). We observed W Hya with VLT/SPHERE-ZIMPOL at three wavelengths in the continuum (645, 748, and 820 nm), in the Halpha line at 656.3 nm, and in the TiO band at 717 nm. The VLTI/AMBER observations were carried out in the wavelength region of the CO first overtone lines near 2.3 micron with a spectral resolution of 12000. Taking advantage of the polarimetric imaging capability of SPHERE-ZIMPOL combined with the superb adaptive optics performance, we have succeeded in spatially resolving three clumpy dust clouds located at ~50 mas (~2 Rstar) from the central star, revealing dust formation very close to the star. The AMBER data in the individual CO lines suggest a molecular outer atmosphere extending to ~3 Rstar. Furthermore, the SPHERE-ZIMPOL image taken over the Halpha line shows emission with a radius of up to ~160 mas (~7 Rstar). We found that dust, molecular gas, and Halpha-emitting hot gas are coexisting within 2--3 Rstar. Our modeling suggests that the observed polarized intensity maps can reasonably be explained by large (0.4--0.5 micron) grains of Al2O3 or Mg2SiO4 or MgSiO3 in an optically thin shell with an inner boundary radius of 1.9--2.0 Rstar. The observed clumpy structure can be reproduced by a density enhancement by a factor of 4 +/- 1. The grain size derived from our polarimetric images is consistent with the prediction of the hydrodynamical models for the mass loss driven by the scattering due to micron-sized grains. The detection of the clumpy dust clouds close to the star lends support to the dust formation induced by pulsation and large convective cells as predicted by the 3-D simulations for AGB stars., 12 pages, 9 figures, accepted for publication in Astronomy and Astrophysics, short discussion of non-equilibrium gas-dust chemistry models added

International audience; Context. The mass loss from massive stars is not understood well. Eta Car is a unique object for studying the massive stellar wind during the LBV phase. It is also an eccentric binary with a period of 5.54 yr. The nature of both stars is uncertain, although we know from X-ray studies that there is a wind-wind collision whose properties change with orbital phase. Methods. Observations of Eta Car were carried out with the ESO VLTI and the AMBER instrument between approximately five and seven months before the August 2014 periastron passage. Velocity-resolved aperture-synthesis images were reconstructed from the spectrally dispersed interferograms. Interferometric studies can provide information on the binary orbit, the primary wind, and the wind collision. Results. We present velocity-resolved aperture-synthesis images reconstructed in more than 100 different spectral channels distributed across the Br Gamma 2.166 micrometer emission line. The intensity distribution of the images strongly depends on wavelength. At wavelengths corresponding to radial velocities of approximately -140 to -376 km/s measured relative to line center, the intensity distribution has a fan-shaped structure. At the velocity of -277 km/s, the position angle of the symmetry axis of the fan is ~ 126 degree. The fan-shaped structure extends approximately 8.0 mas (~ 18.8 au) to the southeast and 5.8 mas (~ 13.6 au) to the northwest, measured along the symmetry axis at the 16% intensity contour. The shape of the intensity distributions suggests that the obtained images are the first direct images of the innermost wind-wind collision zone. Therefore, the observations provide velocity-dependent image structures that can be used to test three-dimensional hydrodynamical, radiative transfer models of the massive interacting winds of Eta Car.

We describe a combined dynamic atmosphere and maser propagation model of SiO maser emission in Mira variables. This model rectifies many of the defects of an earlier model of this type, particularly in relation to the infra-red (IR) radiation field generated by dust and various wavelength-dependent, optically thick layers. Modelled masers form in rings with radii consistent with those found in VLBI observations and with earlier models. This agreement requires the adoption of a radio photosphere of radius approximately twice that of the stellar photosphere, in agreement with observations. A radio photosphere of this size renders invisible certain maser sites with high amplification at low radii, and conceals high-velocity shocks, which are absent in radio continuum observations. The SiO masers are brightest at an optical phase of 0.1 to 0.25, which is consistent with observed phase-lags. Dust can have both mild and profound effects on the maser emission. Maser rings, a shock and the optically thick layer in the SiO pumping band at 8.13\micron appear to be closely associated in three out of four phase samples.

Infrared spectro-interferometry provides us with a unique opportunity to study the circumstellar environment of cool evolved stars in great detail, with spectral and spatial information disentangled. Recently, ESO’s Very Large Telescope Interferometer (VLTI) has shed new light on the molecule and dust formation close to the photosphere or the structure of circumstellar disks around cool evolved stars. Our VLTI/MIDI observations of the oxygen-rich Mira star RR Sco have revealed the wavelength dependence of the angular size of the Mira star from 8 to 13 μm, which can be well explained by the presence of extended and dense H 2 O layers and an optically thin dust shell. On the other hand, our MIDI observations of the silicate carbon star IRAS08002-3803 indicate the presence of an optically thick circumbinary disk, but the dust chemistry in the disk has turned out to be more complicated than previously thought. These results demonstrate the power of spectro-interferometry for obtaining new insights into the circumstellar environment of cool evolved stars.

We present recent results from our project of concurrent radio and infrared interferometry of oxygen-rich Mira stars. Our pilot study on the Mira variable S Ori included coordinated VLBA mapping of the v=1, J=1-0 43.1 GHz and v=2, J=1-0 42.8 GHz SiO maser radiation at one epoch and concurrent near-infrared K-band interferometry to constrain the stellar photospheric diameter. We recently obtained new maps of these SiO maser transitions toward S Ori at three additional epochs with the VLBA and concurrent mid-infrared interferometric data with VLTI/MIDI. The MIDI data are analyzed using recent self-excited dynamic model atmospheres including molecular shells close to continuum-forming layers, which we complement by a radiative transfer model of the dust shell. The modelling of our MIDI data results in phase-dependent continuum photospheric angular diameters. The dust shell can best be modelled with Al2O3 grains alone. We find that the mean SiO maser ring radii lie between about 1.9 and 2.4 stellar continuum radii. The maser spots mark the region of the molecular atmospheric layers shortly outward of the steepest decrease of the mid-infrared model intensity profile. Our results suggest that the SiO maser shells are co-located with the Al2O3 dust shell near minimum visual phase. Their velocity structure indicates a radial gas expansion. Preliminary results from a study of the Mira star GX Mon suggest a similar picture.

The young stellar object MWC 297 has been observed with the VLT interferometer equipped with the AMBER instrument. MWC 297 has been spatially resolved in the continuum with a visibility of 0.50 as well as in the Br gamma emission line where the visibility decrease to a lower value of 0.33. This change in the visibility with the wavelength can be interpreted by the presence of an optically thick disk responsible for the visibility in the continuum and of a stellar wind traced by Br gamma and whose apparent size is 40% larger. We validate this interpretation by building a model of the stellar environment that combines a geometrically thin, optically thick accretion disk model consisting of gas and dust, and a latitude-dependent stellar wind outflowing above the disk surface. The continuum emission and visibilities obtained from this model are fully consistent with the interferometric AMBER data. They agree also with existing optical, near-infrared spectra and other broad-band near-infrared interferometric visibilities. A picture emerges in which MWC 297 is surrounded by an equatorial flat disk that is possibly still accreting and an outflowing wind which has a much higher velocity in the polar region than at the equator. [abridged]

Aims. We study the geometry and kinematics of the circumstellar environment of the Be star Kappa CMa in the Br gamma emission line and its nearby continuum. Methods. We use the VLTI/AMBER instrument operating in the K band which provides a spatial resolution of about 6 mas with a spectral resolution of 1500 to study the kinematics within the disk and to infer its rotation law. In order to obtain more kinematical constraints we also use an high spectral resolution Pa beta line profile obtain in December 2005 at the Observatorio do Pico do Dios, Brazil and we compile V/R line profile variations and spectral energy distribution data points from the literature. Results. Using differential visibilities and differential phases across the Br gamma line we detect an asymmetry in the disk. Moreover, we found that kappa CMa seems difficult to fit within the classical scenario for Be stars, illustrated recently by alpha Arae observations, i.e. a fast rotating B star close to its breakup velocity surrounded by a Keplerian circumstellar disk with an enhanced polar wind. Finally we discuss the possibility for kappa CMa to be a critical rotator with a Keplerian rotating disk and try to see if the detected asymmetry can be interpreted within the "one-armed" viscous disk framework.

A static random access memory (SRAM) cell circuit, constructed using Si interband tunneling diodes (IBTDs) and a metal-oxide-semiconductor field effect transistor (MOSFET), is presented. The Si-IBTD is a negative differential resistance (NDR) device with a tunneling dielectric between a degenerate p + -diffusion layer and an n + -poly-Si electrode. The Si-IBTD was monolithically integrated with the MOSFET on a silicon-on-insulator (SOI) wafer by a novel fabrication process and a compact SRAM cell circuit consisting of two Si-IBTDs and a MOSFET was fabricated. The Si-IBTD shows a full process compatibility with a conventional MOSFET process. Data-read/write operations of this SRAM cell circuit were successfully demonstrated at ultra-low voltage, below 0.5 V, even at room temperature. Simulation results showed that downscaling of the Si-IBTD size was effective for improving the circuit speed. A writing time of the memory cell with a Si-IBTD size of 0.1 μ m 2 was reduced to 0.8 ns in simulation. The Si-IBTD/MOSFET merged SRAM can be considered one of the most promising candidates for future low-power device applications.

We present the results of a quantitative analysis of 12C/13C ratios in 62 N-type, 15 SC-type, and 26 J-type carbon stars. The 12C/13C ratios are determined from lines of the CN Red System around 8000 Å, based on the iso-intensity method and line-blanketed model atmospheres. The resulting 12C/13C ratios in N- and SC-type carbon stars are consistent with a scenario in which M giants evolve through SC- to N-type carbon stars, as 12C produced during thermal pulses is added to the envelope.

Dust should be formed in the photosphere of cool brown dwarfs, but it is not clear in what form the dust exists. We propose a model in which a rather warm dust layer exists deep in the photosphere. At relatively high temperature there, dust grains are in detailed balance with the gas and the homogeneous dust-gas mixture works as an efficient source of opacity. The warm dust layer, which can be optically thick in the optical region, effectively blocks the optical radiation and emits like a blackbody of rather high temperature. The dust layer, however, can be optically thin in the infrared and has little effect on the infrared radiation. In the cool upper region, dust grows too large to be sustained with the gas and segregates from the gaseous atmosphere. Dust no longer works as an opacity source, and volatile molecules such as CH4 and H2O take the role. Also, nonrefractory elements such as alkali metals remain in gaseous form, and the neutral atoms contribute significantly to block the optical radiation (e.g., K I doublet). We show that such a hybrid model can be constructed without any ad hoc assumption except that the transition from the dust-gas detailed balance regime to the dust-gas segregation phase takes place at a certain transition temperature Ttr. By a sudden increase of opacity due to dust at Ttr, an outer convective zone appears, followed by intermediate radiative and inner deep convective zones. The emergent spectrum is also a hybrid of the dust- and gas-dominated cases and offers a natural explanation of the observed spectrum of Gliese 229B through the optical to the infrared.

We carried out observations of bright optical carbon stars with the ISO SWS, and detected the absorption features of CO, CS, CH, SiS and HCN in N-type and SC-type stars. The CH fundamental bands in 3-4 μm in N-type stars are stronger than those in SC-type stars. On the other hand, the first overtone bands of SiS at 6.6 μm were detected in WZ Cas (SC-type), while none of them were detected in N-type stars. These results can be explained well by the lower C/O ratio in SC-type stars than in N-type stars. The absorption features of HCN (v1, v2 + v3 and v1 − v2) are stronger in SC-type stars than in N-type stars. This fact can be explained by the cooler atmospheres of our SC-type stars due to the lower C/O ratio as well as due to the lower effective temperature, compared with the N-type stars in our sample. The CS bands and the band heads of the CO fundamental bands are weaker in the observed spectra than in those predicted by our model atmospheres. This result cannot be explained by the present model atmosphere and one possible explanation is the contribution by the emission of CO and CS in the outer atmosphere.

Infrared spectra of carbon stars are of great importance in the understanding the stellar evolution at the asymptotic giant branch (AGB). The analysis of elemental abundances of carbon, nitrogen, and oxygen, which is indispensable to understand the nuclear processes in AGB stars, can be done based on high-resolution infrared spectra. In addition, infrared spectra of carbon stars bring us information on the physics and chemistry in the circumstellar envelope.

Overall SEDs based on ISO SWS observations show fair agreement with photospheric model predictions for red (super)giant stars. However, some details of molecular spectra cannot be explained by a photospheric origin. In particular, fine structure in the H2O 2.7µm band can be clearly resolved by the SWS and is identified in an early M giant, whose photosphere will never produce H2O. This is definite evidence for H2O of non-photospheric origin in an early M giant. Also, the observed H2O and CO2 bands in a late M giant are too strong to be explained by a photospheric origin alone. Further, the H2O 2.7 µm band is found in four early M supergiants in the h + χ Persei clusters (three of which show UIRs) and is especially strong in the M4 supergiant S Per (which also shows a highly peculiar SED). Thus, against a belief that H2O is found only in the latest M giants such as Miras, the SWS has revealed the presence of H2O in a wider region of the HR diagram. The origin of this H2O is unknown but is probably in a non-photospheric extra envelope. Such a H2O envelope appears to be a general feature through early M (super)giants to cool supergiants such as S Per, where the envelope has finally developed to be optically thick.

We have developed the neutron polarization measurement system to perform the first polarization-transfer measurement for the exclusive [Formula: see text] reaction. For the neutron polarization measurement, we have reconstructed the neutron polarimeter NPOL3. The NPOL3 system has been calibrated by using the polarized neutron from the [Formula: see text] reaction, and the resulting effective analyzing power is [Formula: see text]. For the exclusive measurement, the Large Acceptance Spectrometer (LAS) has been used for the recoil proton detection. The energy resolution of 6 MeV is achieved for separation energy, which is sufficient to separate the [Formula: see text] and [Formula: see text] orbits for light nuclei.

We present the first 1-D aperture synthesis imaging of the red supergiant Betelgeuse in the individual CO first overtone lines with VLTI/AMBER. The reconstructed 1-D projection images reveal that the star appears differently in the blue wing, line center, and red wing of the individual CO lines. The 1-D projection images in the blue wing and line center show a pronounced, asymmetrically extended component up to ~1.3 stellar radii, while those in the red wing do not show such a component. The observed 1-D projection images in the lines can be reasonably explained by a model in which the CO gas within a region more than half as large as the stellar size is moving slightly outward with 0--5 km s^-1, while the gas in the remaining region is infalling fast with 20--30 km s^-1. A comparison between the CO line AMBER data taken in 2008 and 2009 shows a significant time variation in the dynamics of the CO line-forming region in the photosphere and the outer atmosphere. In contrast to the line data, the reconstructed 1-D projection images in the continuum show only a slight deviation from a uniform disk or limb-darkened disk. We derive a uniform-disk diameter of 42.05 +/- 0.05 mas and a power-law-type limb-darkened disk diameter of 42.49 +/- 0.06 mas and a limb-darkening parameter of (9.7 +/- 0.5) x 10^{-2}. This latter angular diameter leads to an effective temperature of 3690 +/- 54 K for the continuum-forming layer. These diameters confirm that the near-IR size of Betelgeuse was nearly constant over the last 18 years, in marked contrast to the recently reported noticeable decrease in the mid-IR size. The continuum data taken in 2008 and 2009 reveal no or only marginal time variations, much smaller than the maximum variation predicted by the current 3-D convection simulations., Comment: 21 pages, 12 figures, accepted for publication in Astronomy and Astrophysics

This paper describes the design goals and engineering efforts that led to the realization of AMBER (Astronomical Multi BEam combineR) and to the achievement of its present performance. On the basis of the general instrumental concept, AMBER was decomposed into modules whose functions and detailed characteristics are given. Emphasis is put on the spatial filtering system, a key element of the instrument. We established a budget for transmission and contrast degradation through the different modules, and made the detailed optical design. The latter confirmed the overall performance of the instrument and defined the exact implementation of the AMBER optics. The performance was assessed with laboratory measurements and commissionings at the VLTI, in terms of spectral coverage and resolution, instrumental contrast higher than 0.80, minimum magnitude of 11 in K, absolute visibility accuracy of 1%, and differential phase stability of 1E-3 rad over one minute., Comment: 14 pages

Aims. We present the first NIR spectro-interferometry of the LBV ? Carinae. The observations were performed with the AMBER instrument of the ESO Very Large Telescope Interferometer (VLTI) using baselines from 42 to 89 m. The aim of this work is to study the wavelength dependence of ? Car's optically thick wind region with a high spatial resolution of 5 mas (11 AU) and high spectral resolution. Methods: The observations were carried out with three 8.2 m Unit Telescopes in the K-band. The raw data are spectrally dispersed interferograms obtained with spectral resolutions of 1500 (MR-K mode) and 12 000 (HR-K mode). The MR-K observations were performed in the wavelength range around both the He I 2.059 ?m and the Br? 2.166 ?m emission lines, the HR-K observations only in the Br? line region. Results: The spectrally dispersed AMBER interferograms allow the investigation of the wavelength dependence of the visibility, differential phase, and closure phase of ? Car. In the K-band continuum, a diameter of 4.0±0.2 mas (Gaussian FWHM, fit range 28-89 m baseline length) was measured for ? Car's optically thick wind region. If we fit Hillier et al. (2001, ApJ, 553, 837) model visibilities to the observed AMBER visibilities, we obtain 50% encircled-energy diameters of 4.2, 6.5 and 9.6 mas in the 2.17 ?m continuum, the He I, and the Br? emission lines, respectively. In the continuum near the Br? line, an elongation along a position angle of 120°±15° was found, consistent with previous VINCI/VLTI measurements by van Boekel et al. (2003, A&A, 410, L37). We compare the measured visibilities with predictions of the radiative transfer model of Hillier et al. (2001), finding good agreement. Furthermore, we discuss the detectability of the hypothetical hot binary companion. For the interpretation of the non-zero differential and closure phases measured within the Br? line, we present a simple geometric model of an inclined, latitude-dependent wind zone. Our observations support theoretical models of anisotropic winds from fast-rotating, luminous hot stars with enhanced high-velocity mass loss near the polar regions. Based on observations collected at the European Southern Observatory, Paranal, Chile, within the AMBER guaranteed time programme 074.A-9025 and the VLTI science demonstration programme 074.A-9024.

International audience; In this work, we present the first AMBER observations, of the Wolf-Rayet and O (WR+O) star binary system y² Velorum. The AMBER instrument was used with the telescopes UT2, UT3, and UT4 on baselines ranging from 46m to 85m. It delivered spectrally dispersed visibilities, as well as differential and closure phases, with a resolution R = 1500 in the spectral band 1.95-2.17 micron. We interpret these data in the context of a binary system with unresolved components, neglecting in a first approximation the wind-wind collision zone flux contribution. We show that the AMBER observables result primarily from the contribution of the individual components of the WR+O binary system. We discuss several interpretations of the residuals, and speculate on the detection of an additional continuum component, originating from the free-free emission associated with the wind-wind collision zone (WWCZ), and contributing at most to the observed K-band flux at the 5% level. The expected absolute separation and position angle at the time of observations were 5.1±0.9mas and 66±15° respectively. However, we infer a separation of 3.62+0.11-0.30 mas and a position angle of 73+9-11°. Our analysis thus implies that the binary system lies at a distance of 368+38-13 pc, in agreement with recent spectrophotometric estimates, but significantly larger than the Hipparcos value of 258+41-31 pc.

Located in the Orion Trapezium cluster, Theta 1 Orionis C is one of the youngest and nearest high-mass stars (O5-O7) and also known to be a close binary system. Using new multi-epoch visual and near-infrared bispectrum speckle interferometric observations obtained at the BTA 6 m telescope, and IOTA near-infrared long-baseline interferometry, we trace the orbital motion of the Theta 1 Ori C components over the interval 1997.8 to 2005.9, covering a significant arc of the orbit. Besides fitting the relative position and the flux ratio, we apply aperture synthesis techniques to our IOTA data to reconstruct a model-independent image of the Theta 1 Ori C binary system. The orbital solutions suggest a high eccentricity (e approx. 0.91) and short-period (P approx. 10.9 yrs) orbit. As the current astrometric data only allows rather weak constraints on the total dynamical mass, we present the two best-fit orbits. From these orbital solutions one can be favoured, implying a system mass of 48 M_sun and a distance to the Trapezium cluster of 434 pc. When also taking the measured flux ratio and the derived location in the HR-diagram into account, we find good agreement for all observables, assuming a spectral type of O5.5 for Theta 1 Ori C1 (M=34.0 M_sun) and O9.5 for C2 (M=15.5 M_sun). We find indications that the companion C2 is massive itself, which makes it likely that its contribution to the intense UV radiation field of the Trapezium cluster is non-negligible. Furthermore, the high eccentricity of the preliminary orbit solution predicts a very small physical separation during periastron passage (approx. 1.5 AU, next passage around 2007.5), suggesting strong wind-wind interaction between the two O stars., Comment: 13 pages, 9 figures, Accepted for publication in Astronomy & Astrophysics

We present the first multi-epoch study that includes concurrent mid-infrared and radio interferometry of an oxygen-rich Mira star. We obtained mid-infrared interferometry of S Ori with VLTI/MIDI at four epochs between December 2004 and December 2005. We concurrently observed v=1, J=1-0 (43.1 GHz), and v=2, J=1-0 (42.8 GHz) SiO maser emission toward S Ori with the VLBA at three epochs. The MIDI data are analyzed using self-excited dynamic model atmospheres including molecular layers, complemented by a radiative transfer model of the circumstellar dust shell. The VLBA data are reduced to the spatial structure and kinematics of the maser spots. The modeling of our MIDI data results in phase-dependent continuum photospheric angular diameters between about 7.9 mas (Phase 0.55) and 9.7 mas (Phase 1.16). The dust shell can best be modeled with Al2O3 grains using phase-dependent inner boundary radii between 1.8 and 2.4 photospheric radii. The dust shell appears to be more compact with greater optical depth near visual minimum, and more extended with lower optical depth after visual maximum. The ratios of the SiO maser ring radii to the photospheric radii are between about 1.9 and 2.4. The maser spots mark the region of the molecular atmospheric layers just beyond the steepest decrease in the mid-infrared model intensity profile. Their velocity structure indicates a radial gas expansion. Al2O3 dust grains and SiO maser spots form at relatively small radii of 1.8-2.4 photospheric radii. Our results suggest increased mass loss and dust formation close to the surface near the minimum visual phase, when Al2O3 dust grains are co-located with the molecular gas and the SiO maser shells, and a more expanded dust shell after visual maximum. Silicon does not appear to be bound in dust, as our data show no sign of silicate grains., Comment: Accepted for publication in A&A. See ESO press release 25/07 at http://www.eso.org/public/outreach/press-rel/pr-2007/pr-25-07.html

Two interferometric instruments at ESO's Very Large Telescope Interferometer (VLTI), MIDI and AMBER which operate in the mid‐infrared (8–13 μm) and the near‐infrared (JHK) respectively, have proven to be powerful tools to probe the circumstellar environment of evolved stars. Their spectro‐interferometric capability enables us to observe objects with spectral and spatial information disentangled. VLTI observations confirm our pictures on the circumstellar environment of cool evolved stars in some cases but bring about entirely unexpected pictures for other cases. Here, we present particularly our recent results obtained with VLTI/MIDI.

We investigate the origin of the $\mathrm{Br}\gamma$ emission of the Herbig Ae star HD104237 on Astronomical Unit (AU) scales. Using AMBER/VLTI at a spectral resolution R=1500 spatially resolve the emission in both the BrGamma line and the adjacent continuum. The visibility does not vary between the continuum and the BrGamma line, even though the line is strongly detected in the spectrum, with a peak intensity 35% above the continuum. This demonstrates that the line and continuum emission have similar size scales. We assume that the K-band continuum excess originates in a ``puffed-up'' inner rim of the circumstellar disk, and discuss the likely origin of BrGamma. We conclude that this emission most likely arises from a compact disk wind, launched from a region 0.2-0.5 AU from the star, with a spatial extent similar to that of the near infrared continuum emission region, i.e, very close to the inner rim location., Comment: 4 pages, 2 figures, accepted in A&A

High-power operation (35 mW/spl times/2) at 70/spl deg/C in a 680 nm band individually addressable AlGaInP/GaInP 2-beam laser diode has been demonstrated for the first time. The 2-beam laser diode employs V-grooves for electrode separation and reduction of laser capacitance, and accurate junction-down bonding to silicon carbide (SiC) submount. Therefore, simultaneous high-power operation, high frequency response and high reliability are achieved. >

We report a patient with pure word deafness after subcortical hemorrhage in the left temporal lobe. Repetition and auditory comprehension were severely impaired, while reading and visual comprehension of the same material were almost normal. He did not show hearing loss, but speech discrimination and melody recognition was poor. On the speech discrimination test, his score was low especially in the right ear. The threshold on the directional hearing test was mildly elevated. There was no temporal summation by click sounds. CT and MRI disclosed a subcortical hematoma in the left superior temporal gyrus. PET demonstrated hypoperfusion in the surrounding area, which was not activated by hearing a story. It was considered that pure word deafness in this case was due to the interruption of auditory inputs to Wernicke's area from both hemisphere by the hematoma. After 5 months, auditory comprehension recovered so that he did not have difficulty in conversation. Speech discrimination improved in both ears, probably due to the recovery of two auditory pathways; the ipsilateral pathway through the left auditory radiation and the contralateral pathway through the right auditory radiation and the corpus callosum. This case suggests that in pure word deafness due to a unilateral lesion, the improvement in speech discrimination during follow-up period may provide a clue as to the site of the responsible lesion and its recovery.

We present the first N-band nulling plus K- and L-band V2 observations of a young stellar object, MWC325, taken with the 85 m baseline Keck Interferometer. The Keck nuller was designed for the study of faint dust signatures associated with debris disks, but it also has a unique capability for studying the temperature and density distribution of denser disks found around young stellar objects. Interferometric observations of MWC 325 at K, L and N encompass a factor of five in spectral range and thus, especially when spectrally dispersed within each band, enable characterization of the structure of the inner disk regions where planets form. Fitting our observations with geometric models such as a uniform disk or a Gaussian disk show that the apparent size increases monotonically with wavelength in the 2-12 um wavelength region, confirming the widely held assumption based on radiative transfer models, now with spatially resolved measurements over broad wavelength range, that disks are extended with a temperature gradient. The effective size is a factor of about 1.3 and 2 larger in the L-band and N-band, respectively, compared to that in the K-band. The existing interferometric measurements and the spectral energy distribution can be reproduced by a flat disk or a weakly-shadowed nearly flat-disk model, with only slight flaring in the outer regions of the disk, consisting of representative "sub-micron" (0.1 um) and "micron" (2 um) grains of a 50:50 ratio of silicate and graphite. This is marked contrast with the disks previously found in other Herbig Ae/Be stars suggesting a wide variety in the disk properties among Herbig Ae/Be stars., Comment: Accepted for publication in the ApJ

We isolated a genomic clone containing 2558 bp of the 5'-flanking region and 217 bp of the first exon for the human type-1 angiotensin II receptor (AT1) gene. Primer extension and RNAase protection analyses identified a transcriptional start site (+1) at 39 and 114 bp downstream of putative TATA and GC boxes, respectively. Chimeras containing 2.6 kbp(-2558 to +79) of the 5'-flanking region and chloramphenicol acetyltransferase (CAT) gene expressed a significant CAT activity when transfected into bovine aortic smooth muscle cells (BASMC), but not the cells which had no detectable AT1 receptors, such as HeLa cells and primary cultured human skin fibroblasts. Deletion of the 5'-flanking region up to position -114 resulted in more than 20-fold increase of the reporter activity in BASMC, suggesting the presence of negatively regulating element(s) in the upstream promoter region. These results indicate that we have cloned a functional promoter for the human AT1 receptor gene.

We obtained 13 epochs of mid-infrared interferometry with the MIDI instrument at the VLTI between April 2004 and July 2007, covering pulsation phases 0.45-0.85 within four cycles. The data are modeled with a radiative transfer model of the dust shell where the central stellar intensity profile is described by a series of dust-free dynamic model atmospheres based on self-excited pulsation models. We examined two dust species, silicate and Al2O3 grains. We performed model simulations using variations in model phase and dust shell parameters to investigate the expected variability of our photometric and interferometric data. The observed visibility spectra do not show any indication of variations as a function of pulsation phase and cycle. The observed photometry spectra may indicate intracycle and cycle-to-cycle variations at the level of 1-2 standard deviations. The best-fitting model for our average pulsation phase of 0.64+/-0.15 includes the dynamic model atmosphere M21n (T_model=2550 K) with a photospheric angular diameter of 7.6+/-0.6 mas, and a silicate dust shell with an optical depth of 2.8+/-0.8, an inner radius of 4.1+/-0.7 R_Phot, and a power-law index of the density distribution of 2.6+/-0.3. The addition of an Al2O3 dust shell did not improve the model fit. The photospheric angular diameter corresponds to a radius of 520^+230_-140 R_sun and an effective temperature of ~ 2420+/-200 K. Our modeling simulations confirm that significant visibility variations are not expected for RR Aql at mid-infrared wavelengths within our uncertainties. We conclude that our RR Aql data can be described by a pulsating atmosphere surrounded by a silicate dust shell. The effects of the pulsation on the mid-infrared flux and visibility values are expected to be less than about 25% and 20%, respectively, and are too low to be detected within our measurement uncertainties., 16 pages, 14 figures. Accepted for publication in A&A

Pharmacological studies have revealed the presence of two different subtypes (AT1 and AT2) for angiotensin II (Ang II) receptor. Recently, bovine and rat cDNAs of AT1 receptor were cloned by expression cloning. We have isolated a cDNA encoding human AT1 receptor from a human liver cDNA library, using rat AT1 receptor cDNA as a probe. Human AT1 receptor consists of 359 amino acid residues with a relative Mr of 41,060 and seven transmembrane segments, and was highly homologous to those of bovine, rat and mouse AT1 receptors. Southern blot analysis suggested that human AT1 receptor is a single copy gene.

To clarify the role of a novel vasoactive peptide endothelin in endocrine hypertension, we examined endothelin (ET)-like immunoreactivity and the ET binding sites in the tissues of two pheochromocytoma. Case 1 was a 25-year-old woman who manifested multiple endocrine neoplasia (MEN) II b with left adrenal pheochromocytoma, and case 2 was a 48-year-old woman with familial bilateral pheochromocytoma. In both cases, fairly high amount of ET-like immunoreactivity was detected in the resected tumors. By competitive binding analysis, high affinity binding sites for 125I-ET-1 were also detected in the same resected tissues. Concomitant existence of ET and its receptor suggests that ET may play an important role in these tumors in modulating the secretion of catecholamines from the tumors by an autocrine/paracrine fashion.

Red supergiants (RSGs) experience slow, intensive mass loss up to 10−4M⊙ yr−1. Despite its importance not only in stellar evolution but also in the chemical enrichment of the interstellar matter, the mass loss mechanism in RSGs is not well understood. A better understanding of the outer atmosphere of RSGs is a key to unraveling the mass-loss mechanism in these stars. High spatial resolution observations in IR molecular lines are very effective for probing the physical properties of the inhomogeneous outer atmosphere. We observed the prototypical RSG Betelgeuse (M1-2Ia–Ibe) in the CO first overtone lines with the spectro-interferometric instrument AMBER at the ESO's Very Large Telescope Interferometer (VLTI) using baselines of 16, 32, and 48 m. Details of the observations and the modeling are described in Ohnaka et al. (2009). The high-spectral (R = 4800–12000) and high-spatial resolution (9 mas) provided with AMBER allowed us to study inhomogeneities seen in the individual CO first overtone lines. Our AMBER observations represent the highest spatial resolution achieved for Betelgeuse, corresponding to five resolution elements over its stellar disk. The AMBER visibilities and closure phases in the K-band continuum can be reasonably fitted by a uniform disk with a diameter of 43.19 ± 0.03 mas or a limb-darkening disk with 43.56 ± 0.06 mas and a limb-darkening parameter of (1.2 ± 0.07) × 10−1. On the other hand, our AMBER data in the CO lines reveal salient inhomogeneous structures. The visibilities and phases (closure phases, as well as differential phases representing asymmetry in lines with respect to the continuum) measured within the CO lines show that the blue and red wings originate in spatially distinct regions over the stellar disk, indicating an inhomogeneous velocity field that makes the star appear different in the blue and red wings. Our AMBER data in the CO lines can be roughly explained by a simple model, in which a patch of CO gas is moving outward or inward with velocities of 10–15 km s−1, while the CO gas in the remaining region in the atmosphere is moving in the opposite direction at the same velocities. These velocities compare favorably with the macroturbulent velocities of 10–20 km s−1 derived by spectroscopic analyses. Also, the AMBER data are consistent with the presence of warm molecular layers (so-called MOLsphere) extending to ~1.4–1.5 R* with a CO column density of ~ 1 × 1020 cm−2. However, the present data are insufficient to constrain the surface pattern uniquely or to reconstruct an image. Our AMBER observations of Betelgeuse are the first spatially resolved study of the macroturbulence in a stellar atmosphere (photosphere and possibly MOLsphere as well) other than the Sun. The spatially resolved CO gas motion is likely to be related to convective motion in the upper atmosphere or intermittent mass ejections in clumps or arcs.

The incubation of big endothelin-1 (big ET-1), big ET-2 or big ET-3 with cultured bovine endothelial cells (ECs) resulted in their conversions to mature endothelins (ETs). These conversions apparently exhibited Michaelis-Menten kinetics as a function of each big ET isopeptide. The conversions of big ETs were abolished by phosphoramidon. These results indicate that vascular endothelium can convert exogenous big ET-1 to mature ET-1 through a phosphoramidon-sensitive metalloprotease, and that this enzyme has also high affinities for big ET-2 and big ET-3.