399 research outputs found

    Ammonia mapping observations of the Galactic infrared bubble N49: Three NH3_3 clumps along the molecular filament

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    We have carried out the NH3_3 (J,K)=(1,1),(2,2),(J,K)=(1,1),(2,2), and (3,3)(3,3) mapping observations toward the Galactic infrared bubble N49 (G28.83-0.25) using the Nobeyama 45 m telescope. Three NH3_3 clumps (A, B, and C) were discovered along the molecular filament with the radial velocities of \sim 96, 87, and 89 km s1^{-1}, respectively. The kinetic temperature derived from the NH3_3 (2,2)/NH3_3 (1,1) shows Tkin=27.0±0.6T_{\rm kin} = 27.0 \pm 0.6 K enhanced at Clump B in the eastern edge of the bubble, where position coincides with massive young stellar objects (MYSOs) associated with the 6.7 GHz class II methanol maser source. This result shows the dense clump is locally heated by stellar feedback from the embedded MYSOs. The NH3_3 Clump B also exists at the 88 km s1^{-1} and 95 km s1^{-1} molecular filament intersection. We therefore suggest that the NH3_3 dense gas formation in Clump B can be explained by a filament-filament interaction scenario. On the other hand, NH3_3 Clump A and C at the northern and southern side of the molecular filament might be the sites of spontaneous star formation because these clumps are located \sim5-10 pc away from the edge of the bubble.Comment: 29 pages, 13 figures, 3 tables, accepted for Publications of the Astronomical Society of Japan (PASJ

    Hagedorn Strings and Correspondence Principle in AdS(3)

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    Motivated by the possibility of formulating a strings/black hole correspondence in AdS space, we extract the Hagedorn behavior of thermal AdS_3 bosonic string from 1-loop partition function of SL(2,R) WZW model. We find that the Hagedorn temperature is monotonically increasing as the AdS radius shrinks, reaches a maximum of order of string scale set by the unitarity bound of the CFT for internal space. The resulting density of states near the Hagedorn temperature resembles the form as for strings in flat space and is dominated by the space-like long string configurations. We then argue a conjectured strings/black hole correspondence in AdS space by applying the Hagedorn thermodynamics. We find the size of the corresponding black hole is a function of the AdS radius. For large AdS radius a black hole far bigger than the string scale will form. On the contrary, when the AdS and string scales are comparable a string size black hole will form. We also examine strings on BTZ background obtained through SL(2,Z) transformation. We find a tachyonic divergence for a BTZ black hole of string scale size.Comment: 28 pages, 4 figures;v2 references added & appear on JHE

    Vortex Lattice Structures of a Bose-Einstein Condensate in a Rotating Lattice Potential

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    We study vortex lattice structures of a trapped Bose-Einstein condensate in a rotating lattice potential by numerically solving the time-dependent Gross-Pitaevskii equation. By rotating the lattice potential, we observe the transition from the Abrikosov vortex lattice to the pinned lattice. We investigate the transition of the vortex lattice structure by changing conditions such as angular velocity, intensity, and lattice constant of the rotating lattice potential.Comment: 6 pages, 8 figures, submitted to Quantum Fluids and Solids Conference (QFS 2006

    Drag force in SYM plasma with B field from AdS/CFT

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    We investigate drag force in a thermal plasma of N=4 super Yang-Mills theory via both fundamental and Dirichlet strings under the influence of non-zero NSNS BB-field background. In the description of AdS/CFT correspondence the endpoint of these strings correspondes to an external monopole or quark moving with a constant electromagnetic field. We demonstrate how the configuration of string tail as well as the drag force obtains corrections in this background.Comment: 13 pages, 2 figures, more discussion and reference adde

    Case Report Sequential MR Images and Radiographs of Epiphyseal Osteomyelitis in the Distal Femur of an Infant

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    Magnetic resonance imaging (MRI) plays an important role in the diagnosis of osteomyelitis, especially during the early phase of the disease. The findings of sequential MRIs during the course of treatment in acute osteomyelitis in children have not yet been reported in the literature. We present a case of acute epiphyseal osteomyelitis in the distal femur of an infant. We monitored imaging changes by sequential MRIs and radiographs. MRI was more useful than radiograph for early diagnosis and evaluation of therapeutic response
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