5,359 research outputs found

    An Off-Axis Galaxy Cluster Merger: Abell 0141

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    We present structural analysis results of Abell 0141 (zz = 0.23) based on X-ray data. The X-ray luminosity map demonstrates that Abell 0141 (A0141) is a bimodal galaxy cluster, which is separated on the sky by ∼\sim 0.65 Mpc with an elongation along the north-south direction. The optical galaxy density map also demonstrates this bimodality. We estimate sub-cluster ICM temperatures of 5.17−0.19+0.20^{+0.20}_{-0.19} keV for A0141N and 5.23−0.23+0.24^{+0.24}_{-0.23} keV for A0141S. We obtain X-ray morphological parameters w = 0.034±0.004\pm{0.004}, c = 0.113±0.004\pm{0.004} and w = 0.039±0.004\pm{0.004}, c = 0.104±0.005\pm{0.005} for A0141N and A0141S, respectively. The resulting X-ray morphological parameters indicate that both sub-clusters are moderately disturbed non-cool core structures. We find a slight brightness jump in the bridge region, and yet, there is still an absence of strong X-ray emitting gas between sub-clusters. We discover a significantly hotspot (∼\sim 10 keV) between sub-clusters, and a Mach number M\textit{M} = 1.69−0.37+0.40^{+0.40}_{-0.37} is obtained by using the temperature jump condition. However, we did not find direct evidence for shock-heating between sub-clusters. We estimate the sub-clusters' central entropies as K0K_{0} > 100 keV cm2^{2}, which indicates that the sub-clusters are not cool cores. We find some evidence that the system undergoes an off-axis collision; however, the cores of each sub-clusters have not yet been destroyed. Due to the orientation of X-ray tails of sub-clusters, we suggest that the northern sub-cluster moves through the south-west direction, and the southern cluster moves through the north-east direction. In conclusion, we are witnessing an earlier phase of close core passage between sub-clusters.Comment: 9 pages, 4 figure

    Production of carbon nanotubes by PECVD and their applications to supercapacitors

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    Màster en Nanociència i NanotecnologiaPlasma enhanced chemical vapor deposition (PECVD) is a versatile technique to obtain vertically dense-aligned carbon nanotubes (CNTs) at lower temperatures than chemical vapor deposition (CVD). In this work, we used magnetron sputtering to deposit iron layer as a catalyst on silicon wafers. After that, radio frequency (rf) assisted PECVD reactor was used to grow CNTs. They were treated with water plasma and finally covered by MnO2 as dielectric layer in order to use CNTs as electrode for supercapacitors. Optimization of annealing time, reaction time and temperature, water plasma time and MnO2 deposition time were performed to find appropriate conditions to improve the characteristics of supercapacitors. SEM (Scanning Electron Microscopy), TEM (Transmission Electron Microscopy), AFM (Atomic Force Microscopy) and Raman spectroscopy were used to characterize obtained electrodes

    A theoretical approach for Pareto-Zipf law

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    We suggest an analytical approach for Pareto-Zipf law, where we assume random multiplicative noise and fragmentation processes for the growth of the number of citizens of each city and the number of the cities, respectively.Comment: 6 pages 2 figures and dated for IJMPC Volume 19 presumably issue

    A new model for competition between many languages

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    Time evolutions of number of cities, population of cities, world population, and size distribution of present languages are studied in terms of a new model, where population of each city increases by a random rate and decreases by a random division. World population and size distribution of languages come out in good agreement with the available empirical data.Comment: 6 pages 5 figure
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