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[en] The impurity problem is one of the most important areas of study for improving Heliotron-E currentless plasmas. Impurity reduction by 2.45 GHz ECH discharge cleaning and the impurity flux in the edge region of the NBI currentless plasmas were studied by using a newly installed surface analysis station with an 'in-situ' AES system. It was confirmed that the light impurities such as C and O were well reduced by the discharge cleaning. The amount of metal impurities on the α-Si probe surface exposed to the plasma increased as the NBI power increased. The impurity level observed in one side of the probe inserted into the edge region of the NBI plasma was larger than that in the opposite side. (orig.)
[en] An attractive scheme for investigating compact structure in weak radio sources is to study the scintillation properties of confusion in a large single-dish radio telescope. We have investigated the utility of this technique by observing the scintillations of 860-MHz confusion of the NRAO 300' (91 m) telescope. Analysis of these data indicated a reduction in the mean scintillation index with decreasing flux density which implied that weaker sources possessed less compact structure. More direct observations indicated that the weak sources of interest were not significantly deficient in compact structure, so the first result is probably due to properties of the IPS process in the strong scintillation regime. Our results may be due to overresolution (by the IPS process in the strong scintillation regime) of the ''hot spots'' responsible for scintillation in most strong sources at frequencies below 1000 MHz, or may indicate abnormally strong turbulence in the solar wind during August, 1977. Future applications of this method would be best conducted at lower frequencies with larger reflectors or short-spacing interferometers
[en] We present 38'' resolution maps of the CO and 13CO J = 2-1 lines in the molecular clouds toward the H II region complex W51. The maps cover a 1.025 x 10 section of the galactic plane and span +30 to +85 km s-1 (LSR) in velocity. The spectral resolution is ∼1.3 km s-1. The velocity range of the images includes all the gas in the Sagittarius spiral arm. Color figures display the peak line brightness temperature, the velocity-integrated intensity, and 2 km s-1 channel-averaged maps for both isotopologs, and also the CO/13CO J = 2-1 line intensity ratio as a function of velocity. The CO and 13CO line intensity image cubes are made available in standard FITS format as electronically readable tables. We compare our molecular line maps with the 1.1 mm continuum image from the BOLOCAM Galactic Plane Survey. From our 13CO image cube, we derive kinematic information for the 99 BGPS sources in the mapped field in the form of Gaussian component fits. The integrated 13CO line intensity and the 1.1 mm source flux density show only a modest degree of correlation for the 99 sources, likely due to a range of dust and gas physical conditions within the sources. However, the 1.1 mm continuum surface brightness and the integrated 13CO line intensity for small regions containing single BGPS sources and molecular clouds show very good correlations in many cases. Differences in the shapes of these correlations from one spatial region to another probably result from different physical conditions or structure in the clouds.
[en] Reconstructions of total solar irradiance (TSI) rely mainly on linear relations between TSI variation and indices of facular area. When these are extrapolated to the prolonged 15th-17th century Spoerer and Maunder solar activity minima, the estimated solar dimming is insufficient to explain the mid-millennial climate cooling of the Little Ice Age. We draw attention here to evidence that the relation departs from linearity at the lowest activity levels. Imaging photometry and radiometry indicate an increased TSI contribution per unit area from small network faculae by a factor of 2-4 compared with larger faculae in and around active regions. Even partial removal of this more TSI-effective network at prolonged minima could enable climatically significant solar dimming, yet be consistent with the weakened but persistent 11 yr cycle observed in Be 10 during the Maunder Minimum. The mechanism we suggest would not alter previous findings that increased solar radiative forcing is insufficient to account for 20th century global warming.
[en] In the context of the VLA-COSMOS Deep project, additional VLA A array observations at 1.4 GHz were obtained for the central degree of the COSMOS field and combined with the existing data from the VLA-COSMOS Large project. A newly constructed Deep mosaic with a resolution of 2.''5 was used to search for sources down to 4σ with 1σ ∼ 12 μJy beam-1 in the central 50' x 50'. This new catalog is combined with the catalog from the Large project (obtained at 1.''5 x 1.''4 resolution) to construct a new Joint catalog. All sources listed in the new Joint catalog have peak flux densities of ≥5σ at 1.''5 and/or 2.''5 resolution to account for the fact that a significant fraction of sources at these low flux levels are expected to be slightly resolved at 1.''5 resolution. All properties listed in the Joint catalog, such as peak flux density, integrated flux density, and source size, are determined in the 2.''5 resolution Deep image. In addition, the Joint catalog contains 43 newly identified multi-component sources.
[en] A multicontact probe placed near the wall has been used to study the distribution of the divertor fluxes over the minor azimuth in stellarator and torsatron regimes of the Saturn machine. It has been found that the plasma flux towards the outer part of the torus is much higher than the flux measured along the direction to the inner part. The plasma fluxes are localized in the vicinity of the apexes of the magnetic surfaces and their azimuthal width near the wall does not exceed 1/18th of the vacuum chamber circumference. (author)
[en] We report the first results of a program to investigate the continuum flux densities at 1410 MHz for all BL-Lacertae objects known south of declination - 100. These sources were monitored nearly weekly in the interval April 1985-February 1987, with the 30 m radiotelescope of the Instituto Argentino de Radioastronomia. We find that 50% of the objects with flux density above 1 Jy underwent variations. The present measurements are compared with previous ones made between June 1982 and October 1983. The comparison suggests that from the objects which showed no activity in any previous monitoring program, all but one (PKS 0818-128), are still inactive on this longer time base
[en] It is stated that extragalactic radio sources fall into one of two categories. In one the emission is extended, with two main peaks tens or hundreds of kiloparsecs apart straddling the associated optical object, while in the other the source is compact (typically less than a kiloparsec in size), with optical and radio positions that coincide to within the errors of measurement. More rarely, double sources may belong to a third category, which has been classified as D2, and of which the type example is 3C273. Sources of this class consist of a small variable nuclear component coincident with the optical object, and a second larger component with a much steeper spectrum. High resolution observations made with radio-link interferometers based on Jodrell Bank are here reported, which show that the QSOs 3C345 and 3C454.3 have extended radio structure similar to that of 3C273. Hence these sources, previously believed to be compact, should also be classified as D2. Details of the observations are given. (author)