SuzakuSuzaku X-ray study of the double radio relic galaxy cluster CIZA J2242.8+5301

Content: We present the results from $Suzaku$ observations of the merging cluster of galaxies CIZA J2242.8+5301 at $z$=0.192. Aims. To study the physics of gas heating and particle acceleration in cluster mergers, we investigated the X-ray emission from CIZA J2242.8+5301, which hosts two giant radio relics in the northern/southern part of the cluster. Methods. We analyzed data from three-pointed Suzaku observations of CIZA J2242.8+5301 to derive the temperature distribution in four different directions. Results: The Intra-Cluster Medium (ICM) temperature shows a remarkable drop from 8.5$_{-0.6}^{+0.8}$ keV to 2.7$_{-0.4}^{+0.7}$ keV across the northern radio relic. The temperature drop is consistent with a Mach number ${\cal M}_n=2.7^{+0.7}_{-0.4}$ and a shock velocity $v_{shock:n}=2300_{-400}^{+700}\rm\,km\,s^{-1}$. We also confirm the temperature drop across the southern radio relic. However, the ICM temperature beyond this relic is much higher than beyond the northern one, which gives a Mach number ${\cal M}_s=1.7^{+0.4}_{-0.3}$ and shock velocity $v_{shock:s}=2040_{-410}^{+550}\rm \,km\,s^{-1}$. These results agree with other systems showing a relationship between the radio relics and shock fronts which are induced by merging activity. We compare the X-ray derived Mach numbers with the radio derived Mach numbers from the radio spectral index under the assumption of diffusive shock acceleration in the linear test particle regime. For the northern radio relic, the Mach numbers derived from X-ray and radio observations agree with each other. Based on the shock velocities, we estimate that CIZA J2242.8+5301 is observed approximately 0.6 Gyr after core passage. The magnetic field pressure at the northern relic is estimated to be 9% of the thermal pressure.Comment: 12 pages, 10 figures, A&A accepte

Reference performance test Methodology for degradation assessment of lithium-sulfur batteries

Lithium-Sulfur (Li-S) is an emerging battery technology receiving a growing amount of attention due to its potentially high gravimetric energy density, safety, and low production cost. However, there are still some obstacles preventing its swift commercialization. Li-S batteries are driven by different electrochemical processes than commonly used Lithium-ion batteries, which often results in very different behavior. Therefore, the testing and modeling of these systems have to be adjusted to reflect their unique behavior and to prevent possible bias. A methodology for a Reference Performance Test (RPT) for the Li-S batteries is proposed in this study to point out Li-S battery features and provide guidance to users how to deal with them and possible results into standardization. The proposed test methodology is demonstrated for 3.4 Ah Li-S cells aged under different conditions

An Experimental and Semi-Empirical Method to Determine the Pauli-Limiting Field in Quasi 2D Superconductors as applied to κ\kappa-(BEDT-TTF)2_2Cu(NCS)2_2: Strong Evidence of a FFLO State

We present upper critical field data for $\kappa$-(BEDT-TTF)$_2$Cu(NCS)$_2$ with the magnetic field close to parallel and parallel to the conducting layers. We show that we can eliminate the effect of vortex dynamics in these layered materials if the layers are oriented within 0.3 degrees of parallel to the applied magnetic field. Eliminating vortex effects leaves one remaining feature in the data that corresponds to the Pauli paramagnetic limit ($H_p$). We propose a semi-empirical method to calculate the $H_p$ in quasi 2D superconductors. This method takes into account the energy gap of each of the quasi 2D superconductors, which is calculated from specific heat data, and the influence of many body effects. The calculated Pauli paramagnetic limits are then compared to critical field data for the title compound and other organic conductors. Many of the examined quasi 2D superconductors, including the above organic superconductors and CeCoIn$_5$, exhibit upper critical fields that exceed their calculated $H_p$ suggesting unconventional superconductivity. We show that the high field low temperature state in $\kappa$-(BEDT-TTF)$_2$Cu(NCS)$_2$ is consistent with the Fulde Ferrell Larkin Ovchinnikov state.Comment: 8 pages, 9 figures, 10 years of dat

In-beam fast-timing measurements in 103,105,107Cd

Fast-timing measurements were performed recently in the region of the medium-mass 103,105,107Cd isotopes, produced in fusion evaporation reactions. Emitted gamma-rays were detected by eight HPGe and five LaBr3:Ce detectors working in coincidence. Results on new and re-evaluated half-lives are discussed within a systematic of transition rates. The $7/2_1^+$ states in 103,105,107Cd are interpreted as arising from a single-particle excitation. The half-life analysis of the $11/2_1^-$ states in 103,105,107Cd shows no change in the single-particle transition strength as a function of the neutron number

Equity Crowdfunders’ Human Capital and Signal Set Formation: Evidence from Eye Tracking

This is the author accepted manuscript. The final version is available from SAGE via the DOI in this record.Signaling theory typically assumes that attention is always given to observable signals. We study signal receivers’ formation of signal sets—the signals to which receivers attend and that they can use for subsequent interpretations. Drawing on a cognitive perspective, we argue that signal receivers’ human capital influences the volume and type of signals they attend to and the time they take to form signal sets. Using eye tracking, we show that equity crowdfunders do not attend to many signals that are easily observable on a campaign page, and that differences in crowdfunders’ human capital uniquely affect their signal set formation.Research Foundation – Flander

A distant radio mini-halo in the phoenix galaxy cluster

We report the discovery of extended radio emission in the Phoenix cluster (SPT-CL J2344-4243, z = 0.596) with the Giant Metrewave Radio Telescope (GMRT) at 610 MHz. The diffuse emission extends over a region of at least 400-500 kpc and surrounds the central radio source of the Brightest Cluster Galaxy, but does not appear to be directly associated with it. We classify the diffuse emission as a radio mini-halo, making it the currently most distant mini-halo known. Radio mini-halos have been explained by synchrotron emitting particles re-accelerated via turbulence, possibly induced by gas sloshing generated from a minor merger event. Chandra observations show a non-concentric X-ray surface brightness distribution, which is consistent with this sloshing interpretation. The mini-halo has a flux density of 17 ± 5 mJy, resulting in a 1.4 GHz radio power of (10.4 ± 3.5) × 1024 W Hz-1. The combined cluster emission, which includes the central compact radio source, is also detected in a shallow GMRT 156 MHz observation and together with the 610 MHz data we compute a spectral index of-0.84 ± 0.12 for the overall cluster radio emission. Given that mini-halos typically have steeper radio spectra than cluster radio galaxies, this spectral index should be taken as an upper limit for the mini-halo. © 2014. The American Astronomical Society. All rights reserved

Ultra-steep spectrum emission in the merging galaxy cluster Abell 1914

A number of radio observations have revealed the presence of large synchrotron-emitting sources associated with the intra-cluster medium. There is strong observational evidence that the emitting particles have been (re-)accelerated by shocks and turbulence generated during merger events. The particles that are accelerated are thought to have higher initial energies than those in the thermal pool but the origin of such mildly relativistic particles remains uncertain and needs to be further investigated. The galaxy cluster Abell 1914 is a massive galaxy cluster in which X-ray observations show clear evidence of merging activity. We carried out radio observations of this cluster with the LOw Frequency ARay (LOFAR) at 150 MHz and the Giant Metrewave Radio Telescope (GMRT) at 610 MHz. We also analysed Very Large Array (VLA) 1.4 GHz data, archival GMRT 325 MHz data, CFHT weak lensing data and Chandra observations. Our analysis shows that the ultra-steep spectrum source (4C38.39; α -2), previously thought to be part of a radio halo, is a distinct source with properties that are consistent with revived fossil plasma sources. Finally, we detect some diffuse emission to the west of the source 4C38.39 that could belong to a radio halo

Fast-timing measurements in 95,96Mo

Half-lives of the 19/2+ and 21/2+ states in 95Mo and of the 8+ and 10+ states in 96Mo were measured. Matrix elements for yrast transitions in 95Mo and 96Mo are discussed.Comment: Proceedings of XIX International School on Nuclear Physics, Neutron Physics and Applications, Varna, Bulgaria, 2011, 5 pages, 6 figure