186 research outputs found

    A Case of Atypical Carcinoid: Harboring Variant 3a/b EML4–ALK Rearrangement

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    X-ray Iron absorption line in Swift J1858.6-0814

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    We present the spectral analysis of bright steady states in an outburst of the transient neutron star low-mass X-ray binary (NS-LMXB) Swift J1858.6-0814 observed with NICER. We detected an ionized iron K absorption line (H-like Fe) at 6.97keV in the spectrum. We estimated the photoionization parameter using the ratio of the equivalent widths (EWs) of the FeXXVI (H-like) (17+\-5eV) and FeXXV (He-like) (<3eV) and discuss the origin of the iron absorption line. The irradiated gas producing the absorption line would locate within (3-6)*1E9cm from the X-ray source. We suggest that the observed H-like Fe absorption line originates from the highly-ionized gas in the inner accretion disk in Swift J1858.6-0814.Comment: 6 pages, 5 figure

    Rotation in the NGC 1333 IRAS 4C Outflow

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    We report molecular line observations of the NGC 1333 IRAS 4C outflow in the Perseus Molecular Cloud with the Atacama Large Millimeter/Submillimeter Array. The CCH and CS emission reveal an outflow cavity structure with clear signatures of rotation with respect to the outflow axis. The rotation is detected from about 120 au up to about 1400 au above the envelope/disk mid-plane. As the distance to the central source increases, the rotation velocity of the outflow decreases while the outflow radius increases, which gives a flat specific angular momentum distribution along the outflow. The mean specific angular momentum of the outflow is about 100 au km/s. Based on reasonable assumptions on the outward velocity of the outflow and the protostar mass, we estimate the range of outflow launching radii to be 5-15 au. Such a launching radius rules out that this outflow is launched as an X-wind, but rather, it is more consistent to be a slow disk wind launched from relatively large radii on the disk. The radius of the centrifugal barrier is roughly estimated, and the role of the centrifugal barrier in the outflow launching is discussed.Comment: Accepted to ApJ. 29 pages, 8 figure

    A Search for Interstellar Carbon Chain Alcohol HC4OH in Star-Forming Region L1527 and Dark Cloud TMC-1

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    We report a sensitive search for the rotational transitions of the carbon chain alcohol HC4OH in the frequency range of 21.2-46.7 GHz in the star-forming region L1527 and the dark cloud TMC-1. The motivation was laboratory detection of HC4OH by microwave spectroscopy. Despite achieving rms noise levels of several millikelvin in the antenna temperature using the 45 m telescope at Nobeyama Radio Observatory, the detection was not successful, leading to 3 sigma upper limits corresponding to the column densities of 2.0 \times 1012 and 5.6 \times 1012 cm-2 in L1527 and TMC-1, respectively. These upper limits indicate that [HC4OH]/[HC5N] ratios are less than 0.3 and 0.1 in L1527 and TMC-1, respectively, where HC5N is an HC4-chain cyanide and HC4OH is a hydroxide. These ratios suggest that the cyano carbon chain molecule dominates the hydroxyl carbon chain molecule in L1527 and TMC-1. This is contrary to the case of saturated compounds in hot cores, e.g., CH3OH and CH3CN, and can be a chemical feature of carbon chain molecules in L1527 and TMC-1. In addition, the column densities of the "unsubstituted" carbon chain molecule C4H and the sulfur-bearing molecules SO and HCS+ were determined from detected lines in L1527.Comment: Astrophysical Journal, in pres

    A Comparison of Japanese and Turkish Mothers’ Views about Self Care Skill Acquisition Age and Their Expectations from Preschools

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    Spanning the vital temporal interval between birth and the elementary school education, the preschool period is one of the most critical times of human life due to its importance in the formation and nourishment of personality. Specifically the preschool education enables children to acquire and develop basic knowledge, skills and habits, thus shaping their social and emotional life, attitudes, beliefs and value judgments. Educational opportunities offered to children in this period facilitate the socio-cultural background for future life. The modern understanding of education designates that preschools are as important as families in providing children with the preliminary education during this period in life. Today, preschool attendance rates for children aged between five to six years (a year prior to starting school) are approximately 60% in Turkey and 97% in Japan. This demonstrates that Japan is significantly ahead of Turkey in the development and popularization of preschool education. Inquring into this discrepancy, this study compares the opinions of mothers, with different economic development levels and culture, on preschool period and education in Japan and Turkey. As such, 300 Turkish and 300 Japanese mothers were given a survey/questionnaire with 21 questions. The frequency and percentage of mothers’ responses were calculated. The results indicate that Turkish and Japanese mothers had certain similar and certain different views. The answers given to nine questions inquiring the opinions of the Japanese and the Turkish mothers on self-care skill acquisition age yields that the Japanese mothers state that suggest that their children acquired self-care skills at earlier ages. When the answers given to the seven questions inquiring mothers’ expectations from preschool education are examined, the results depict very differing opinions. However, based on the answer of the Japanese mothers in the sample, the study concludes that their children acquired self-care skills at a younger age. The questions about mothers’ expectations from preschool institutions received different responses from Japanese and Turkish mothers

    Vertical Structure of the Transition Zone from Infalling Rotating Envelope to Disk in the Class 0 Protostar, IRAS04368+2557

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    We have resolved for the first time the radial and vertical structure of the almost edge-on envelope/disk system of the low-mass Class 0 protostar L1527. For that, we have used ALMA observations with a spatial resolution of 0.25^{\prime\prime}×\times0.13^{\prime\prime} and 0.37^{\prime\prime}×\times0.23^{\prime\prime} at 0.8 mm and 1.2 mm, respectively. The L1527 dust continuum emission has a deconvolved size of 78 au ×\times 21 au, and shows a flared disk-like structure. A thin infalling-rotating envelope is seen in the CCH emission outward of about 150 au, and its thickness is increased by a factor of 2 inward of it. This radius lies between the centrifugal radius (200 au) and the centrifugal barrier of the infalling-rotating envelope (100 au). The gas stagnates in front of the centrifugal barrier and moves toward vertical directions. SO emission is concentrated around and inside the centrifugal barrier. The rotation speed of the SO emitting gas is found to be decelerated around the centrifugal barrier. A part of the angular momentum could be extracted by the gas which moves away from the mid-plane around the centrifugal barrier. If this is the case, the centrifugal barrier would be related to the launching mechanism of low velocity outflows, such as disk winds

    Chemical survey toward young stellar objects in the Perseus molecular cloud complex

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    Chemical diversity of the gas in low-mass protostellar cores is widely recognized. In order to explore its origin, a survey of chemical composition toward 36 Class 0/I protostars in the Perseus molecular cloud complex, which are selected in an unbiased way under certain physical conditions, has been conducted with IRAM 30 m and NRO 45 m telescope. Multiple lines of C2H, c-C3H2 and CH3OH have been observed to characterize the chemical composition averaged over a 1000 au scale around the protostar. The derived beam-averaged column densities show significant chemical diversity among the sources, where the column density ratios of C2H/CH3OH are spread out by 2 orders of magnitude. From previous studies, the hot corino sources have abundant CH3OH but deficient C2H, their C2H/CH3OH column density ratios being relatively low. In contrast, the warm-carbon-chain chemistry (WCCC) sources are found to reveal the high C2H/CH3OH column density ratios. We find that the majority of the sources have intermediate characters between these two distinct chemistry types. A possible trend is seen between the C2H/CH3OH ratio and the distance of the source from the edge of a molecular cloud. The sources located near cloud edges or in isolated clouds tend to have a high C2H/CH3OH ratio. On the other hand, the sources having a low C2H/CH3OH ratio tend to be located in inner regions of the molecular cloud complex. This result gives an important clue to an understanding of the origin of the chemical diversity of protostellar cores in terms of environmental effects.Comment: Accepted for publication in ApJ
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