GWpy is a Python software package that provides an intuitive, object-oriented interface through which to access, process, and visualise data from gravitational-wave detectors. GWpy provides a number ...of new utilities for studying data, as well as an improved user interface for a number of existing tools. The ease-of-use, along with extensive online documentation and examples, has resulted in widespread adoption of GWpy as a basis for Python software development in the international gravitational-wave community.
The first observing run of Advanced LIGO spanned 4 months, from September 12, 2015 to January 19, 2016, during which gravitational waves were directly detected from two binary black hole systems, ...namely GW150914 and GW151226. Confident detection of gravitational waves requires an understanding of instrumental noise transients and artifacts that can reduce the sensitivity of a search for gravitational waves. Studies of the quality of the detector data yield insights into the cause of instrumental artifacts and data quality vetoes specific to a search are produced to mitigate the effects of problematic data. This dissertation provides an overview of the methods used to characterize noise in the LIGO interferometers and provides examples of successful removal of transient noise. The data set used in the first observing run is validated. Further, the systematic removal of noisy data from analysis time is shown to improve the sensitivity of searches for compact binary coalescences. The output of the PyCBC pipeline is used as a metric for improvement. The first direct detection of gravitational waves, GW150914, was a loud enough signal that removing data with excess noise did not improve its significance. However, the removal of data with excess noise decreased the false alarm rate of GW151226 by a factor of 567, from 1 in 320 years (3.9 σ) to 1 in 183000 years (> 5.3 σ).
ABSTRACT
The detection of an intermediate-mass black hole population (102–106 M⊙) will provide clues to their formation environments (e.g. discs of active galactic nuclei, globular clusters) and ...illuminate a potential pathway to produce supermassive black holes. Ground-based gravitational-wave detectors are sensitive to mergers that can form intermediate-mass black holes weighing up to ∼450 M⊙. However, ground-based detector data contain numerous incoherent short duration noise transients that can mimic the gravitational-wave signals from merging intermediate-mass black holes, limiting the sensitivity of searches. Here, we follow-up on binary black hole merger candidates using a ranking statistic that measures the coherence or incoherence of triggers in multiple-detector data. We use this statistic to rank candidate events, initially identified by all-sky search pipelines, with lab-frame total masses ≳ 55 M⊙ using data from LIGO’s second observing run. Our analysis does not yield evidence for new intermediate-mass black holes. However, we find support for eight stellar-mass binary black holes not reported in the first LIGO–Virgo gravitational wave transient catalogue GWTC-1, seven of which have been previously reported by other catalogues.
Parametric instabilities have long been studied as a potentially limiting effect in high-power interferometric gravitational wave detectors. Until now, however, these instabilities have never been ...observed in a kilometer-scale interferometer. In this work we describe the first observation of parametric instability in an Advanced LIGO detector, and the means by which it has been removed as a barrier to progress.
The R3B-GLAD (GSI Large Acceptance superconducting Dipole) magnet provides the magnetic field needed for the R3B (Reaction studies with Radioactive Relativistic Beams) experiment which will be ...implemented on the future FAIR Facility (Facility for Antiproton and Ion Research). There are six trapezoidal racetrack coils for the R3B-GLAD magnet. Two main coils and four lateral coils are connected in series in a butterfly-like shape. The total weight of the six coils is 5.2 t. The cold mass assembly consists of coils, coil-casings, structural linking components and other non-structural components. The cold mass assembly weighs 22 t with envelope dimensions of 3.1 m (L) × 4.6 m (W) × 2.8 m (H). It is supported by the three cold to warm cryogenic supports. The magnet configuration was finalized in June 2008. The final cold mass design was accomplished end of July 2008. The manufacturing of the cold mass assembly has been launched since January 2009. The cold mass will be ready for test in the test station at CEA Saclay by the end of 2010. This paper gives an overview on the final design of the R3BGLAD cold mass assembly and manufacturing status.
The detection of an intermediate-mass black hole population (\(10^2-10^6\) \(M_{\odot}\)) will provide clues to their formation environments (e.g., disks of active galactic nuclei, globular clusters) ...and illuminate a potential pathway to produce supermassive black holes. Ground-based gravitational-wave detectors are sensitive to mergers that can form intermediate-mass black holes weighing up to \(\sim 450\ M_{\odot}\). However, ground-based detector data contain numerous incoherent short duration noise transients that can mimic the gravitational-wave signals from merging intermediate-mass black holes, limiting the sensitivity of searches. Here we follow-up on binary black hole merger candidates using a ranking statistic that measures the coherence or incoherence of triggers in multiple-detector data. We use this statistic to rank candidate events, initially identified by all-sky search pipelines, with lab-frame total masses \(>55\ M_{\odot}\) using data from LIGO's second observing run. Our analysis does not yield evidence for new intermediate-mass black holes. However, we find support for eight stellar-mass binary black holes not reported in the first LIGO-Virgo gravitational wave transient catalog GWTC-1, seven of which have been previously reported by other catalogs.
Acte I Massinger, Philip; Middleton, Thomas; Rowley, William
Etudes epistémè,
2007
Journal Article
Recenzirano
Odprti dostop
L’Excellente comédie intitulée La Loi des anciens, ou Comment vous plaire à nouveau. Par Philip Massinger, Thomas Middleton, William Rowley. PERSONNAGES DE LA PIÈCE ÉVANDRE, DUC d’ÉPIRECRÉON, père de ...SIMONIDESIMONIDE, CLÉANTHE, deux courtisansLYSANDRE, époux d’EUGÉNIEet oncle de CLÉANTHELÉONIDE, un vieil homme, père de CLÉANTHEANTIGONE, mère de SIMONIDE, épouse de CRÉONHIPPOLITA, épouse de CLÉANTHEEUGÉNIE, épouse de LYSANDRE et belle-mère de PARTHÉNIAPARTHÉNIA, belle-fille d’ EU...
Acte 3, scène 1 Entrent le rustaud et le clerc de la paroisse. RUSTAUDVous avez examiné le registre paroissial, Monsieur ? CLERCOui, Monsieur, et j’ai découvert l’âge précis et la date de la partie ...qui vous intéresse. RUSTAUDMais couvrez-vous, Monsieur. CLERCVous m’avez montré l’exemple, Monsieur. RUSTAUDOh, Monsieur, n’oubliez pas que vous êtes clerc. CLERCUn petit clerc, Monsieur. RUSTAUDEt sans doute un homme très sage, car on dit que les plus grands clercs ne le sont pas toujours. CLERC...
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