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We carried out large–scale (4 × 2 degree) CO multi–line observations toward the central molecular zone (CMZ) in the Galactic center (GC) with the NANTEN2 4m telescope and mapped several diffuse molecular features located at relatively high Galactic latitudes above 0°.6. These high–latitude features are composed of diffuse molecular halo gas and molecular filaments according to their morphological aspects. Their high velocities and high intensity ratios between 12CO J = (2−1) and J = (1−0) clearly indicate their location in the GC, and their total mass amount to ∼10% of that of the CMZ. We discuss that magnetic field is a possible mechanism of these high–latitude molecular features lifting up toward high galactic latitude.
A method is proposed to evaluate the power brightness of an intense pulsed ion beam by using a Thomson parabola spectrometer (TPS). In the method, the time-dependent power brightness of each ion species can be determined independently from the density profile of ion tracks. The method is successfully utilized to evaluate the power brightness of ion beams produced in point pinch diode. The brightness of highly ionized carbons of 660 keV and oxygens of 880 keV, and singly ionized molecular ions of 400 keV, are evaluated independently. The total brightness is evaluated to be 3.2 GW/cm2/sr for highly ionized ions, and 1.9 GW/cm2/sr for molecular ions.
Zero-dimensional numerical computation of electrical discharge-pumped excimer lasers is extended to a one-dimensional model that is used to study the effects of the density perturbations of the background neutral gas and the nonuniform predischarge (which means preionization in this paper) electron density on the transition of the uniform discharge to the nonuniform prestage state leading to the onset of arc formation (which is not included in this particular model). It was found that a local density depression of 1% or an enhancement of the local electric field of 1% can increase the local energy input by several hundred percent. The initial electron density perturbations, on the other hand, are found to modify the energy input by the same order of magnitude as the initial perturbations.
In order to compare the bubble dynamics of various quantum liquids, we performed the visual observation of a sound-induced bubble in a normal liquid 4He, pure superfluid 4He, and superfluid 3He–4He liquid mixtures of saturated and unsaturated 3He concentrations. When an acoustic wave pulse was applied to these liquids under saturated vapour pressure, a macroscopic bubble was generated on the surface of a piezoelectric transducer. For all liquids, the size of the bubble increased, as a higher voltage was applied to the transducer at a fixed temperature. In the normal 4He we observed a primary bubble surrounded with many small bubbles which ascended upward together. In contrast to normal phase, only one bubble was generated in the superfluid 4He, and its shape proved to be highly irregular with an ill-defined surface. In the 3He saturated superfluid mixture, we also observed a solitary bubble but with a nearly perfect spherical shape. The bubble in this mixture expanded on the transducer surface, grew to a maximum size of the order of 1 mm and then started shrinking. As the bubble detached from the transducer with shrinking, we clearly detected an origination of the upward jet flow which penetrated the bubble. The jet velocity in the liquid mixture was approximately 102–103 times smaller than in water. At the final stage of the process we could sometimes observe a vortex ring generation. It is interesting that, though the bubble size and time scale of the phenomenon differ from those in water, the behaviour in the collapsing process had much in common with the simulation study of the vortex ring generation in water. In addition, for the mixture with the unsaturated 3He concentration of about 25% at 600 mK, the shape of the upward jet was observed distinctly, using more precise measurement with shadowgraph method.
Atacama Submillimeter Telescope Experiment (ASTE) is a joint project between Japan and Chile for installing and operating a 10 m high precision telescope in the Atacama Desert in order to explore the southern sky through the submillimeter wavelength. We have achieved an accuracy of 19 μm (rms) for the main reflector surface and a stable radio pointing accuracy of about 2 arcsec (rms). A 350 GHz cartridge type SIS mixer receiver achieves good performance with a typical system noise temperature of 150 ~ 250 K in DSB and a main beam efficiency of 0.6 ~ 0.7 during winter nights.
A large scale CO(3-2) imaging survey of nearby galaxies using ASTE is now in progress. One of our goals is to compare our wide area CO(3-2) images with existing CO(1-0) data as well as distributions of massive star formation tracers (i.e., Hα and radio continuum emission) in order to understand the physical mechanism which controls the global star formation properties such as star formation efficiency. Initial CO(3-2) maps of some sample galaxies (M 83, NGC 604 in M 33, NGC 1672, & NGC 7130) are reported.
Division XI was born by merging Commission 44 “Space and High Energy Astrophysics” and Commission 48 “High Energy Astrophysics” by the decision at the IAU General Assembly in The Hague (1994). As the naming of space astronomy is technique oriented, i.e. astronomy from space, it covers quite a wide range of astronomy, almost all branches of astronomy are included by the progress of space observations. Historically, it started from high energy astronomy, UV, X, and gamma rays astronomy, somewhat including cosmic ray physics. However, in these days, space observations have expanded to low energy astronomy, such as optical, infrared, submillimeter and even radio waves(Space VLBI).
Direct characterization of band alignment at chemical bath deposition (CBD)-CdS/Cu0.93 (In1-xGax)Se2 has been carried out by photoemission spectroscopy (PES) and inverse photoemission spectroscopy (IPES). Ar ion beam etching at the condition of the low ion kinetic energy of 350 eV yields a removal of surface contamination as well as successful measurement of the intrinsic properties of each layer and the interfaces. Especially interior regions of the wide gap CIGS layers with a band gap of 1.4 ∼ 1.6 eV were successfully exposed. IPES spectra revealed that the conduction band offset (CBO) at the interface region of the wide gap CIGS with x = 0.60 and 0.75 was negative, where the conduction band minimum of CdS was lower than that of CIGS. It was also observed that the energy spacing between conduction band minimum (CBM) of CdS layer and valence band maximum (VBM) of Cu0.93(In0.25Ga0.75)Se2 layer at interface region was no wider than that of the interface over the Cu0.93(In0.60Ga0.40)Se2 layer.
Influences of the continuity of the matrix on Young's modulus and tensile strength of unidirectional SiC/SiC mini-composite prepared by the polymer impregnation and pyrolysis method were studied experimentally by observation of appearance of matrix and tensile test and analytically by a shear lag–Monte Carlo simulation. The continuity of the matrix was improved by the addition of particles such as ZrSiO4, barium magnesium aluminosilicate, and Pyrex (borosilicate glass) into the matrix. The improved continuity of the matrix led to the increase in stress carrying capacity of the matrix and therefore to the increase in Young's modulus and tensile strength of the composite. Such a correlation between the continuity of the matrix and the property of the composite was verified numerically by the shear lag–Monte Carlo simulation.
We present initial results of a deep mid-infrared surveyconducted in the high galactic latitude field SSA13 with ISO.We have surveyed through the broad band filterLW2 (5-8.5 μm)of the mid-infrared camera ISOCAMto probe the near-infrared light at high redshift.The 80% completeness limit for point sources in the central6 arcmin2 reaches 10 μJy at 6.7 μm.65 sources are detected down to 6 μJy in 16 arcmin2.The integral galaxy number countsare 1.4 × 104 deg-2at 10 μJy with the slope of -1.5.The integrated 6.7 μm light down to 6 μJyis estimated as 0.43 nWm-2sr-1.Our counts are consistent withthe results in the HDF andthe model predictionbased on the K band local luminosity function.It suggests thatthe majority of the detected sources areE/S0 galaxies at z>1.
Faint submillimeter sources detected with JCMT/SCUBAhave faced an identification problem due to their broad beam profiles.Here we propose a new method to identify these sourcesat the mid-infrared utilizing a finer point spread function.ISOCAM has provided us a very deep 6.7 μm image of the Hawaii Deep Field SSA13.For all three 850 μm sources in this field,we have found their 6.7 μm counterparts.All of them have been identified with interacting galaxy pairs at the optical.Two of the pairs are very faint and red (I>24, I - K > 4),one of the two has the hard X-ray detection with Chandra.Assuming an Arp 220 SED,we have found a typical redshift of z ~ 2.This requiresthat the sources should be a few times more luminous than Arp 220.It appears that extremely high star formation ratesare occurring in galaxies at high redshiftwith massive stellar contents already in place.
The Japanese infrared space missions in the past and the future are briefly summarized with some historical and strategic view points. Starting with simple ground based observations, we have been putting an emphasis on space missions with less affected by the poor Japanese climate conditions for infrared observations using balloons, rockets and satellites. Focusing on diffuse infrared emissions, which are favorably observable by small and simple instruments, we have succeeded in getting unique results of zodiacal light, Galactic and extragalactic emissions as well as the cosmic background radiation.
We present the characteristics of far-infrared (FIR) brightness fluctuations at 90 μm and 170 μm in the Lockman Hole, which were surveyed with the ISOPHOT instrument aboard the Infrared Space Observatory (ISO), and give constraints on the galaxy number counts down to 30 mJy at 90 μm and 50 mJy at 170 μm. The fluctuation power spectra of the FIR images are not dominated by IR cirrus, and are instead most likely due to star-forming galaxies. This analysis indicates the existence of strong evolution in the counts. Especially at 90 μm, the source density is much larger than that expected from the currently available galaxy count models. The galaxies responsible for the fluctuations also significantly contribute to the cosmic infrared background radiation recently derived from an analysis of the COBE data.
Fibreoptic bronchoscopy is often used to diagnose tracheomalacia under local anaesthesia. However, in children, general anaesthesia may be required due to difficulty in obtaining co-operation. A 1-yr-old girl with a suspected congenital tracheomalacia was scheduled for diagnostic fibreoptic bronchoscopy. During induction of anaesthesia by inhalation of increasing concentration of sevoflurane, spontaneous breathing became irregular and a partial airway obstruction occurred. Because vecuronium relieved the airway obstruction, the airway was managed using a laryngeal mask. No further airway obstruction occurred during fibrescopy under controlled ventilation, but when spontaneous breathing resumed, marked airway obstruction occurred. The trachea was intubated immediately. Caution is required to manage the airway without tracheal intubation during general anaesthesia in the patient with tracheomalacia.
The reporting period has shown that Space has become a firmly established domain in observational Astrophysics, also in the low energy astrophysics area. The launching of new spacecraft is always an important addition to the capabilities of the Astronomers, but the availability of space observatories is strongly affected by the fact that they disappear as their subsystems become damaged or, for other reasons, become inoperable. The relatively short life of astronomical space facilities has generated new dynamic in the life cycle of observational tools for the astronomer, rather different from that for ground facilities. Launch failures or the final in-orbit functionality verification can also very strongly affect the availability of observational capabilities in space astrophysics. The only spacecraft designed without this built-in life time restriction, is the Hubble Space Telescope, which can be serviced by the Space Shuttle.
The idea for a Working Group (WG) on “Future Large Scale Facilities in Astronomy” grew from the Joint Discussion on this topic held on 20 August 1994, during the IAU General Assembly in The Hague. The IAU Executive Committee approved its formation in August, 1995, and Harvey Butcher was chair until the XXIIIrd General Assembly in Kyoto in 1997.
Beam smoothing techniques and focused beam profile control techniques for high efficiency KrF laser fusion are reported. We have developed 1D and 2D broadband random phase (BRP) irradiation techniques. Our next idea is the combination of a laser oscillator with a wide beam divergence angle and phase plates. The wide divergence angle laser beam eliminates the speckle patterns caused by the phase plates. Well characterized focal spot patterns have been observed with the front-end pulse of the Super-ASHURA KrF laser system. Amplification experiments are on going.