1,721,103 research outputs found
SUPPLEMENT: "LOCALIZATION AND BROADBAND FOLLOW-UP OF THE GRAVITATIONAL-WAVE TRANSIENT GW150914" (2016, ApJL, 826, L13)
Full text linkThis Supplement provides supporting material for Abbott et al. (2016a). We briefly summarize past
electromagnetic (EM) follow-up efforts as well as the organization and policy of the current EM follow-up
program. We compare the four probability sky maps produced for the gravitational-wave transient GW150914, and provide additional details of the EM follow-up observations that were performed in the different bands
Search for transient gravitational waves in coincidence with short-duration radio transients during 2007-2013
No full textWe present an archival search for transient gravitational-wave bursts in coincidence with 27 single-pulse
triggers from Green Bank Telescope pulsar surveys, using the LIGO, Virgo, and GEO interferometer
network.We also discuss a check for gravitational-wave signals in coincidence with Parkes fast radio bursts
using similar methods. Data analyzed in these searches were collected between 2007 and 2013. Possible
sources of emission of both short-duration radio signals and transient gravitational-wave emission include
starquakes on neutron stars, binary coalescence of neutron stars, and cosmic string cusps. While no evidence
for gravitational-wave emission in coincidence with these radio transients was found, the current analysis
serves as a prototype for similar future searches using more sensitive second-generation interferometers
Observation of Gravitational Waves from a Binary Black Hole Merger
No full textOn September 14, 2015 at 09: 50: 45 UTC the two detectors of the Laser Interferometer Gravitational-Wave Observatory simultaneously observed a transient gravitational-wave signal. The signal sweeps upwards in frequency from 35 to 250 Hz with a peak gravitational-wave strain of 1.0 x 10(-21). It matches the waveform predicted by general relativity for the inspiral and merger of a pair of black holes and the ringdown of the resulting single black hole. The signal was observed with a matched-filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203 000 years, equivalent to a significance greater than 5.1 sigma. The source lies at a luminosity distance of 410(-180)(+160) Mpc corresponding to a redshift z = 0.09(-0.01)(+0.03). In the source frame, the initial black hole masses are 36(-4)(+5)M(circle dot) and 29(-4)(+4)M(circle dot), and the final black hole mass is 62(-4)(+4) M-circle dot, with 3.0(-0.5)(+0.5) M(circle dot)c(2) radiated in gravitational waves. All uncertainties define 90% credible intervals. These observations demonstrate the existence of binary stellar-mass black hole systems. This is the first direct detection of gravitational waves and the first observation of a binary black hole merger
Erratum: Binary Black Hole Mergers in the First Advanced LIGO Observing Run [Phys. Rev. X 6, 041015 (2016)]
No full textThis is an Erratum to Binary Black Hole Mergers in the First Advanced LIGO Observing Run [Phys. Rev. X 6, 041015 (2016)
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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