38 research outputs found

    Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo

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    Despite the growing number of binary black hole coalescences confidently observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include the effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that have already been identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total source-frame mass M > 70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz emitted gravitational-wave frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place a conservative upper limit for the merger rate density of high-mass binaries with eccentricities 0 < e ≤ 0.3 at 16.9 Gpc−3 yr−1 at the 90% confidence level

    Open data from the third observing run of LIGO, Virgo, KAGRA, and GEO

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    The global network of gravitational-wave observatories now includes five detectors, namely LIGO Hanford, LIGO Livingston, Virgo, KAGRA, and GEO 600. These detectors collected data during their third observing run, O3, composed of three phases: O3a starting in 2019 April and lasting six months, O3b starting in 2019 November and lasting five months, and O3GK starting in 2020 April and lasting two weeks. In this paper we describe these data and various other science products that can be freely accessed through the Gravitational Wave Open Science Center at https://gwosc.org. The main data set, consisting of the gravitational-wave strain time series that contains the astrophysical signals, is released together with supporting data useful for their analysis and documentation, tutorials, as well as analysis software packages

    Us and Me: Team Identification and Individual Differentiation as Complementary Drivers of Team Members' Citizenship and Creative Behaviors

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    The authors investigate team identification and individual differentiation as complementary drivers of team members' citizenship and creative behavior. As hypothesized, the results of a survey among 157 middle-management team members show team identification to be positively related to citizenship behavior toward other team members, whereas individual differentiation is positively associated with creative behavior. Moreover, citizenship behavior is found to be a mediator that linked team identification to an individual's effectiveness as a team member, whereas creative behavior is the mediating link in the relationship between individual differentiation and individual effectiveness. Theoretical implications and suggestions for practitioners are discussed

    Ciclones em Superfície nas Latitudes Austrais: Parte I - Revisão Bibliográfica

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    Resumo Com o objetivo de organizar o conhecimento sinótico sobre ciclones em superfície em latitudes austrais, este trabalho (o primeiro de um conjunto de dois) apresenta uma síntese das principais características de quatro tipos de ciclones: extratropical do tipo Bjerknes e Solberg, extratropical do tipo Shapiro e Keyser, tropical e subtropical. Ao longo do texto são apresentados modelos conceituais bem como os mecanismos de ciclogênese, intensificação e ciclólise de cada tipo de ciclone. As principais diferenças entre os quatros tipos de ciclones em superfície estão nas estruturas horizontais e verticais dos campos de temperatura e vorticidade relativa
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