29 research outputs found

    All-sky search for long-duration gravitational wave transients with initial LIGO

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    We present the results of a search for long-duration gravitational wave transients in two sets of data collected by the LIGO Hanford and LIGO Livingston detectors between November 5, 2005 and September 30, 2007, and July 7, 2009 and October 20, 2010, with a total observational time of 283.0 days and 132.9 days, respectively. The search targets gravitational wave transients of duration 10-500 s in a frequency band of 40-1000 Hz, with minimal assumptions about the signal waveform, polarization, source direction, or time of occurrence. All candidate triggers were consistent with the expected background; as a result we set 90% confidence upper limits on the rate of long-duration gravitational wave transients for different types of gravitational wave signals. For signals from black hole accretion disk instabilities, we set upper limits on the source rate density between 3.4×10-5 and 9.4×10-4 Mpc-3 yr-1 at 90% confidence. These are the first results from an all-sky search for unmodeled long-duration transient gravitational waves. © 2016 American Physical Society

    All-sky search for long-duration gravitational wave transients with initial LIGO

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    We present the results of a search for long-duration gravitational wave transients in two sets of data collected by the LIGO Hanford and LIGO Livingston detectors between November 5, 2005 and September 30, 2007, and July 7, 2009 and October 20, 2010, with a total observational time of 283.0 days and 132.9 days, respectively. The search targets gravitational wave transients of duration 10-500 s in a frequency band of 40-1000 Hz, with minimal assumptions about the signal waveform, polarization, source direction, or time of occurrence. All candidate triggers were consistent with the expected background; as a result we set 90% confidence upper limits on the rate of long-duration gravitational wave transients for different types of gravitational wave signals. For signals from black hole accretion disk instabilities, we set upper limits on the source rate density between 3.4×10-5 and 9.4×10-4 Mpc-3 yr-1 at 90% confidence. These are the first results from an all-sky search for unmodeled long-duration transient gravitational waves. © 2016 American Physical Society

    Erratum: "A Gravitational-wave Measurement of the Hubble Constant Following the Second Observing Run of Advanced LIGO and Virgo" (2021, ApJ, 909, 218)

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    THE RATE OF BINARY BLACK HOLE MERGERS INFERRED FROM ADVANCED LIGO OBSERVATIONS SURROUNDING GW150914

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    A transient gravitational-wave signal, GW150914, was identi fi ed in the twin Advanced LIGO detectors on 2015 September 2015 at 09:50:45 UTC. To asse ss the implications of this discovery, the detectors remained in operation with unchanged con fi gurations over a period of 39 days around the time of t he signal. At the detection statistic threshold corresponding to that observed for GW150914, our search of the 16 days of simultaneous two-detector observational data is estimated to have a false-alarm rate ( FAR ) of < ́ -- 4.9 10 yr 61 , yielding a p -value for GW150914 of < ́ - 210 7 . Parameter estimation follo w-up on this trigger identi fi es its source as a binary black hole ( BBH ) merger with component masses ( )( ) = - + - + mm M ,36,29 12 4 5 4 4 at redshift = - + z 0.09 0.04 0.03 ( median and 90% credible range ) . Here, we report on the constraints these observations place on the rate of BBH coalescences. Considering only GW150914, assuming that all BBHs in the universe have the same masses and spins as this event, imposing a search FAR threshold of 1 per 100 years, and assuming that the BBH merger rate is constant in the comoving frame, we infer a 90% credible range of merger rates between – -- 2 53 Gpc yr 31 ( comoving frame ) . Incorporating all search triggers that pass a much lower threshold while accounting for the uncerta inty in the astrophysical origin of each trigger, we estimate a higher rate, ranging from – -- 13 600 Gpc yr 31 depending on assumptions about the BBH mass distribution. All together, our various rate estimat es fall in the conservative range – -- 2 600 Gpc yr 31

    Workplace Approaches to Obesity Prevention

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    Determinação da digestibilidade da matéria seca e da proteína bruta do fubá de milho e do farelo de soja para tambaqui (Colossoma macropomum), utilizando-se técnicas com uso de indicadores internos e externos Determination of the digestibility of tambaqui (Colossoma macropomum) food nutrients by the techniques with internal and external indicators

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    Foram realizados dois experimentos com o objetivo de comparar técnicas de digestibilidade de nutrientes de alimentos para peixes, com o uso dos indicadores externos (óxido crômico e carbonato de bário) e internos (cinza insolúvel em ácido, cinza insolúvel em detergente ácido, fibra bruta e fibra detergente ácido) e com a técnica de determinação direta. Tambaquis com 100 g receberam, no primeiro experimento, fubá de milho e, no segundo, farelo de soja. O óxido crômico e o carbonato de bário são indicadores externos efetivos para estimar os coeficientes de digestibilidade dos alimentos para tambaquis. A fibra bruta e a fibra detergente ácido apresentaram baixa recuperação e não estimaram de forma consistente os coeficientes de digestibilidade dos alimentos para tambaquis, subestimando-os. A cinza insolúvel em ácido e a cinza insolúvel em detergente ácido apresentaram alta porcentagem de recuperação e estimaram de forma consistente os coeficientes de digestibilidade dos alimentos para tambaquis, quando presentes no alimento em teores acima de 3,8% e 3,1%, respectivamente. A técnica de determinação direta foi eficiente para estimar os coeficientes de digestibilidade dos alimentos para tambaquis.<br>Two experiments were carried out aiming to compare techniques of digestibility of fish food nutrients, by using external indicators (chromic oxide and barium carbonate), internal indicators (HCl-insoluble ash, acid detergent insoluble ash, crude fiber and acid detergent fiber) and the direct determination technique. Corn meal was used in the first experiment and soybean meal was used in the second one; both used 100 g tambaquis. Chromic oxide and barium carbonate are effective external indicators for estimating the digestibility coefficients of feedstuffs fed to tambaquis. Crude fiber and the acid detergent fiber present a low recovery and do not estimate accurately the digestibility coefficients of feedstuffs for tambaquis and also underestimate them. The insoluble ash in acid and the insoluble ash in detergent acid showed high recovery percentage and accurately estimated the digestibility coefficients of feedstuffs fed to tambaquis, when showed contents higher than 3.8 and 3.1, respectively. The direct determination technique was efficient to estimate the digestibility coefficients of the food given to the tambaquis
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