7,737 research outputs found

    Radio Emission from the Composite Supernova Remnant G326.3-1.8 (MSH15-56)

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    High resolution radio observations of the composite supernova remnant (SNR) G326.3-1.8 or MSH 15-56 with the Australia Telescope Compact Array show details of both the shell and the bright plerion which is offset about 1/3 of the distance from the center of the SNR to the shell. The shell appears to be composed of thin filaments, typical of older shell SNRs. The central part of the elongated plerion is composed of a bundle of parallel ridges which bulge out at the ends and form a distinct ring structure on the northwestern end. The magnetic field with a strength of order 45 microGauss, is directed along the axis of the ridges but circles around the northwestern ring. This plerion is large and bright in the radio but is not detected in x-ray or optical wavelengths. There is, however, a faint hard x-ray feature closer to the shell outside the plerion. Perhaps if the supernova explosion left a rapidly moving magnetar with large energy input but initially rapid decay of both relativistic particles and magnetic field, the observed differences with wavelength could be explained.Comment: 15 pages, 10 figures, accepted by Ap

    Time to publication for NIHR HTA programme-funded research: a cohort study

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    ObjectiveTo assess the time to publication of primary research and evidence syntheses funded by the National Institute for Health Research (NIHR) Health Technology Assessment (HTA) Programme published as a monograph in Health Technology Assessment and as a journal article in the wider biomedical literature.Study designRetrospective cohort study.SettingPrimary research and evidence synthesis projects funded by the HTA Programme were included in the cohort if they were registered in the NIHR research programmes database and was planned to submit the draft final report for publication in Health Technology Assessment on or before 9 December 2011.Main outcome measuresThe median time to publication and publication at 30?months in Health Technology Assessment and in an external journal were determined by searching the NIHR research programmes database and HTA Programme website.ResultsOf 458 included projects, 184 (40.2%) were primary research projects and 274 (59.8%) were evidence syntheses. A total of 155 primary research projects had a completion date; the median time to publication was 23?months (26.5 and 35.5?months to publish a monograph and to publish in an external journal, respectively) and 69% were published within 30?months. The median time to publication of HTA-funded trials (n=126) was 24?months and 67.5% were published within 30?months. Among the evidence syntheses with a protocol online date (n=223), the median time to publication was 25.5?months (28?months to publication as a monograph), but only 44.4% of evidence synthesis projects were published in an external journal. 65% of evidence synthesis studies had been published within 30.0?months.ConclusionsResearch funded by the HTA Programme publishes promptly. The importance of Health Technology Assessment was highlighted as the median time to publication was 9?months shorter for a monograph than an external journal article

    Quantum steering ellipsoids, extremal physical states and monogamy

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    A Corrigendum for this article has been published in 2015 New J. Phys. 17 019501Any two-qubit state can be faithfully represented by a steering ellipsoid inside the Bloch sphere, but not every ellipsoid inside the Bloch sphere corresponds to a two-qubit state. We give necessary and sufficient conditions for when the geometric data describe a physical state and investigate maximal volume ellipsoids lying on the physical-unphysical boundary. We derive monogamy relations for steering that are strictly stronger than the Coffman-Kundu- Wootters (CKW) inequality for monogamy of concurrence. The CKW result is thus found to follow from the simple perspective of steering ellipsoid geometry. Remarkably, we can also use steering ellipsoids to derive non-trivial results in classical Euclidean geometry, extending Eulers inequality for the circumradius and inradius of a triangle.The EPSRC and the ARC Centre of Excellence grant no. CE110001027. DJ is funded by the Royal Society. TR would like to thank the Leverhulme Trust. SJ acknowledges EPSRC grant EP/ K022512/1

    Readings from Papyri

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