16 research outputs found

    A Fermi Gamma-Ray Burst Monitor Search for Electromagnetic Signals Coincident with Gravitational-wave Candidates in Advanced LIGO's First Observing Run

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    We present a search for prompt gamma-ray counterparts to compact binary coalescence gravitational wave (GW) candidates from Advanced LIGO's first observing run (O1). As demonstrated by the multimessenger observations of GW170817/GRB 170817A, electromagnetic and GW observations provide complementary information about the astrophysical source, and in the case of weaker candidates, may strengthen the case for an astrophysical origin. Here we investigate low-significance GW candidates from the O1 compact binary coalescence searches using the Fermi Gamma-Ray Burst Monitor (GBM), leveraging its all sky and broad energy coverage. Candidates are ranked and compared to background to measure the significance. Those with false alarm rates (FARs) of less than 10−5 Hz (about one per day, yielding a total of 81 candidates) are used as the search sample for gamma-ray follow-up. No GW candidates were found to be coincident with gamma-ray transients independently identified by blind searches of the GBM data. In addition, GW candidate event times were followed up by a separate targeted search of GBM data. Among the resulting GBM events, the two with the lowest FARs were the gamma-ray transient GW150914-GBM presented in Connaughton et al. and a solar flare in chance coincidence with a GW candidate

    Upper Limits on Gravitational Waves from Scorpius X-1 from a Model-based Cross-correlation Search in Advanced LIGO Data

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    We present the results of a semicoherent search for continuous gravitational waves from the low-mass X-ray binary Scorpius X-1, using data from the first Advanced LIGO observing run. The search method uses details of the modeled, parametrized continuous signal to combine coherently data separated by less than a specified coherence time, which can be adjusted to trade off sensitivity against computational cost. A search was conducted over the frequency range 25–2000Hz2000\,\mathrm{Hz}, spanning the current observationally constrained range of binary orbital parameters. No significant detection candidates were found, and frequency-dependent upper limits were set using a combination of sensitivity estimates and simulated signal injections. The most stringent upper limit was set at 175Hz175\,\mathrm{Hz}, with comparable limits set across the most sensitive frequency range from 100 to 200Hz200\,\mathrm{Hz}. At this frequency, the 95% upper limit on the signal amplitude h 0 is 2.3×10252.3\times {10}^{-25} marginalized over the unknown inclination angle of the neutron star's spin, and 8.0×10268.0\times {10}^{-26} assuming the best orientation (which results in circularly polarized gravitational waves). These limits are a factor of 3–4 stronger than those set by other analyses of the same data, and a factor of ~7 stronger than the best upper limits set using data from Initial LIGO science runs. In the vicinity of 100Hz100\,\mathrm{Hz}, the limits are a factor of between 1.2 and 3.5 above the predictions of the torque balance model, depending on the inclination angle; if the most likely inclination angle of 44° is assumed, they are within a factor of 1.7

    Deep Trek Re-configurable Processor for Data Acquisition (RPDA)

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    This report summarizes technical progress achieved during the cooperative research agreement between Honeywell and U.S. Department of Energy to develop a high-temperature Re-configurable Processor for Data Acquisition (RPDA). The RPDA development has incorporated multiple high-temperature (225C) electronic components within a compact co-fired ceramic Multi-Chip-Module (MCM) package. This assembly is suitable for use in down-hole oil and gas applications. The RPDA module is programmable to support a wide range of functionality. Specifically this project has demonstrated functional integrity of the RPDA package and internal components, as well as functional integrity of the RPDA configured to operate as a Multi-Channel Data Acquisition Controller. This report reviews the design considerations, electrical hardware design, MCM package design, considerations for manufacturing assembly, test and screening, and results from prototype assembly and characterization testing

    Biometric Measures for Interactive Advertising Research

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