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

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

Direito minerário: estudos

Divulgação dos SUMÁRIOS das obras recentemente incorporadas ao acervo da Biblioteca Ministro Oscar Saraiva do STJ. Em respeito à Lei de Direitos Autorais, não disponibilizamos a obra na íntegra. STJ00090338 347.249(81) D598m (2011

Time dissemination services: The experimental results of the European H2020 DEMETRA project

In 2015 and 2016 a European Consortium of 15 scientific and industrial partners from 8 different countries collaborates on the DEMETRA (DEMonstrator of EGNSS services based on Time Reference Architecture) project, funded by the European Union in the frame of the Horizon 2020 program, aimed at developing and experimenting time dissemination services based on the European GNSS. The project aims at being a prototype of an European time dissemination service, based on the timing signal of the Galileo system, adding particular features like - among the others - certification, calibration, or integrity, that could be of interest to a wide range of users belonging to different sectors as traffic control, energy distribution, finance, telecom, and scientific institutions. Nine time dissemination services are proposed. The project is under experimentation since March 2016, we report the first experimentation results of the system, showing potentialities and limits of the proposed services, aiming to foster the development and possibly standardization of the time dissemination services