Using Chandra to Unveil the High-Energy Properties of the High-Magnetic Field Radio Pulsar J1119-6127

(shortened) PSR J1119-6127 is a high magnetic field (B=4.1E13 Gauss), young (<=1,700 year-old), and slow (P=408 ms) radio pulsar associated with the supernova remnant (SNR) G292.2-0.5. In 2003, Chandra allowed the detection of the X-ray counterpart of the radio pulsar, and provided the first evidence for a compact pulsar wind nebula (PWN). We here present new Chandra observations which allowed for the first time an imaging and spectroscopic study of the pulsar and PWN independently of each other. The PWN is only evident in the hard band and consists of jet-like structures extending to at least 7" from the pulsar, with the southern `jet' being longer than the northern `jet'. The spectrum of the PWN is described by a power law with a photon index~1.1 for the compact PWN and ~1.4 for the southern long jet (at a fixed column density of 1.8E22/cm2), and a total luminosity of 4E32 ergs/s (0.5-7 keV), at a distance of 8.4 kpc. The pulsar's spectrum is clearly softer than the PWN's spectrum. We rule out a single blackbody model for the pulsar, and present the first evidence of non-thermal (presumably magnetospheric) emission that dominates above ~3keV. A two-component model consisting of a power law component (with photon index ~1.5--2.0) plus a thermal component provides the best fit. The thermal component can be fit by either a blackbody model with a temperature kT~0.21 keV, or a neutron star atmospheric model with a temperature kT~0.14 keV. The efficiency of the pulsar in converting its rotational power, Edot, into non-thermal X-ray emission from the pulsar and PWN is ~5E-4, comparable to other rotation-powered pulsars with a similar Edot. We discuss our results in the context of the X-ray manifestation of high-magnetic field radio pulsars in comparison with rotation-powered pulsars and magnetars.Comment: 26 pages including 3 tables and 7 figures. Accepted for publication in Ap

Multiplexed communication over a high-speed quantum channel

In quantum information systems it is of particular interest to consider the best way in which to use the non-classical resources consumed by that system. Quantum communication protocols are integral to quantum information systems and are amongst the most promising near-term applications of quantum information science. Here we show that a multiplexed, digital quantum communications system supported by comb of vacuum squeezing has a greater channel capacity per photon than a source of broadband squeezing with the same analogue bandwidth. We report on the time-resolved, simultaneous observation of the first dozen teeth in a 2.4 GHz comb of vacuum squeezing produced by a sub-threshold OPO, as required for such a quantum communications channel. We also demonstrate multiplexed communication on that channel

Kikuchi ultrafast nanodiffraction in four-dimensional electron microscopy

Coherent atomic motions in materials can be revealed using time-resolved X-ray and electron Bragg diffraction. Because of the size of the beam used, typically on the micron scale, the detection of nanoscale propagating waves in extended structures hitherto has not been reported. For elastic waves of complex motions, Bragg intensities contain all polarizations and they are not straightforward to disentangle. Here, we introduce Kikuchi diffraction dynamics, using convergent-beam geometry in an ultrafast electron microscope, to selectively probe propagating transverse elastic waves with nanoscale resolution. It is shown that Kikuchi band shifts, which are sensitive only to the tilting of atomic planes, reveal the resonance oscillations, unit cell angular amplitudes, and the polarization directions. For silicon, the observed wave packet temporal envelope (resonance frequency of 33 GHz), the out-of-phase temporal behavior of Kikuchi's edges, and the magnitude of angular amplitude (0.3 mrad) and polarization [011] elucidate the nature of the motion: one that preserves the mass density (i.e., no compression or expansion) but leads to sliding of planes in the antisymmetric shear eigenmode of the elastic waveguide. As such, the method of Kikuchi diffraction dynamics, which is unique to electron imaging, can be used to characterize the atomic motions of propagating waves and their interactions with interfaces, defects, and grain boundaries at the nanoscale

An Augmented OxRAM Synapse for Spiking Neural Network (SNN) Circuits

International audienceIn this paper, the conductance modulation of OxRAM memristive devices is evaluated based on experimental data to reveal the memristor inherent analog synaptic behavior. Simulation results are presented to validate the use of OxRAMs as synapses at a circuit level in a spiking neural network context. In the proposed approach, the OxRAM synapse is augmented with a shift register associated with current compliance control transistors to provide an efficient monitoring of the OxRAM conductance

The association between region of birth and sexually transmitted infections among people of black Caribbean ethnicity attending sexual health services in England, 2015.

BACKGROUND/INTRODUCTION: In England, people of Black Caribbean (BC) ethnicity are disproportionately affected by sexually transmitted infections (STIs), but it is unclear whether this varies by their region of birth. AIM(S)/OBJECTIVES: To examine differences in STI diagnoses among UK- and Caribbean-born BC people. METHODS: Data on STI diagnoses in BC people attending specialist sexual health services (SHSs) during 2015 and living in England were obtained from the GUMCAD STI surveillance system, the national surveillance system for STIs in England. Associations between being UK- or Caribbean-born and each of several STI diagnoses were examined, using univariate and multivariable generalised estimated equations logistic regression models adjusted for sexual orientation, place of residence (London vs. non-London), HIV status, area-level deprivation, and STI diagnosis in the last year. All analyses were stratified by age (<25 vs. ≥25 years). RESULTS: In 2015, 63,568 BC people made 108,881 attendances at specialist SHSs; 81.9% of these attendances were made by UK-born BCs. The median age (years) was 26 for UK-born and 35 for Caribbean-born people (p≤0.001). Chlamydia, gonorrhoea and non-specific genital infection (NSGI) were the most commonly diagnosed STIs among UK- (5.8%, 2.1% and 2.8%) and Caribbean-born people (4.5%, 1.7% and 3.5%) respectively. Among BCs aged under 25, no significant differences in STIs were found between UK- and Caribbean-born people. Among BCs aged ≥25, compared to Caribbean-born people, those who were UK-born were more likely to be diagnosed with chlamydia (AOR 1.15 [95%C.I. 1.04-1.27]); gonorrhoea (AOR 1.23 [95%C.I. 1.06-1.45]) and genital herpes (AOR 1.23 [95% C.I. 1.10-1.56]) and less likely to be diagnosed with NSGI (AOR 0.89 [95% C.I. 0.80-0.99]) and Trichomoniasis (AOR 0.84 [95% C.I. 0.71-0.99]). DISCUSSION/CONCLUSION: STI diagnoses in BC people aged ≥25 attending specialist SHSs vary by region of birth. Country of birth may have an influence on social and sexual networks and therefore transmission of STIs