1,972 research outputs found

    Asymmetrical bloch branes and the hierarchy problem

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    We investigate a two scalar fields split braneworld model which leads to a possible approach to the hierarchy problem within the thick brane scenario. The model exhibits a resulting asymmetric warp factor suitable for this purpose. The solution is obtained by means of the orbit equation approach for a specific value of one of the parameters. Besides, we analyze the model qualitative behaviour for arbitrary parameters by inspecting the underlying dynamical system defined by the equations which give rise to the braneworld model. We finalize commenting on the metric fluctuation and stability issues.Comment: 8 pages, 7 figure

    High Spatial Resolution of the Mid-Infrared Emission of Compton-Thick Seyfert 2 Galaxy Mrk3

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    Mid-infrared (MIR) spectra observed with Gemini/Michelle were used to study the nuclear region of the Compton-thick Seyfert 2 (Sy 2) galaxy Mrk 3 at a spatial resolution of ∼\sim200 pc. No polycyclic aromatic hydrocarbons (PAHs) emission bands were detected in the N-band spectrum of Mrk 3. However, intense [Ar III] 8.99 μ\mum, [S IV] 10.5 μ\mum and [Ne II] 12.8 μ\mum ionic emission-lines, as well as silicate absorption feature at 9.7μ\mum have been found in the nuclear extraction (∼\sim200 pc). We also present subarcsecond-resolution Michelle N-band image of Mrk 3 which resolves its circumnuclear region. This diffuse MIR emission shows up as a wings towards East-West direction closely aligned with the S-shaped of the Narrow Line Region (NLR) observed at optical [O III]λ\lambda5007\AA image with Hubble/FOC. The nuclear continuum spectrum can be well represented by a theoretical torus spectral energy distribution (SED), suggesting that the nucleus of Mrk 3 may host a dusty toroidal structure predicted by the unified model of active galactic nucleus (AGN). In addition, the hydrogen column density (NH = 4.8−3.1+3.3× 1023_H\,=\,4.8^{+3.3}_{-3.1}\times\,10^{23} cm−2^{-2}) estimated with a torus model for Mrk 3 is consistent with the value derived from X-ray spectroscopy. The torus model geometry of Mrk 3 is similar to that of NGC 3281, both Compton-thick galaxies, confirmed through fitting the 9.7μ\mum silicate band profile. This results might provide further evidence that the silicate-rich dust can be associated with the AGN torus and may also be responsible for the absorption observed at X-ray wavelengths in those galaxies.Comment: 11 pages, 6 figure

    Remarks on supersymmetry of quantum systems with position-dependent effective masses

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    We apply the supersymmetry approach to one-dimensional quantum systems with spatially-dependent mass, by including their ordering ambiguities dependence. In this way we extend the results recently reported in the literature. Furthermore, we point out a connection between these systems and others with constant masses. This is done through convenient transformations in the coordinates and wavefunctions.Comment: 8 pages, 1 figur

    Hematoma Cervical Secundário a Hemorragia Espontânea da Tiroide

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    Spontaneous thyroid haemorrhage is rare, but it can be a potentially life-threatening condition in severe cases, due to acute upper airway compromise. We report the case of a 75-year-old patient on chronic anticoagulation therapy for atrial fibrillation, who presented with sudden painful neck bulging and dysphagia. Physical examination revealed a hard mass on the anterior left side of the neck. Preliminary laryngoscopy was normal. The diagnosis was made using ultrasonography and further characterization with computed tomography, showing haemorrhage of a thyroid nodule with capsular disruption and diffusion of the haematoma to the deep cervical spaces, causing important tracheal deviation and hypopharynx compression. The patient developed dyspnoea and ultimately required urgent hemithyroidectomy. This case also highlights the importance of having a high index of clinical suspicion and prompt imaging in patients with atypical presentations of a neck mass.info:eu-repo/semantics/publishedVersio
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