5,359 research outputs found
An Off-Axis Galaxy Cluster Merger: Abell 0141
We present structural analysis results of Abell 0141 ( = 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 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 keV for A0141N and 5.23 keV for
A0141S. We obtain X-ray morphological parameters w = 0.034, c =
0.113 and w = 0.039, c = 0.104 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 ( 10 keV) between sub-clusters, and a Mach number
= 1.69 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 > 100
keV cm, 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
Mà ster 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
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
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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