Time-domain phenomenological model of gravitational-wave subdominant harmonics for quasicircular nonprecessing binary black hole coalescences

In this work we present an extension of the time domain phenomenological model IMRPhenomT for gravitational wave signals from binary black hole coalescences to include subdominant harmonics, specifically the $(l=2, m=\pm 1)$, $(l=3, m=\pm 3)$, $(l=4, m=\pm 4)$ and $(l=5, m=\pm 5)$ spherical harmonics. We also improve our model for the dominant $(l=2, m=\pm 2)$ mode and discuss mode mixing for the $(l=3, m=\pm 2)$ mode. The model is calibrated to numerical relativity solutions of the full Einstein equations up to mass ratio 18, and to numerical solutions of the Teukolsky equations for higher mass ratios. This work complements the latest generation of traditional frequency domain phenomenological models (IMRPhenomX), and provides new avenues to develop computationally efficient models for gravitational wave signals from generic compact binaries

Parameter estimation with the current generation of phenomenological waveform models applied to the black hole mergers of GWTC-1

We consider the ten confidently detected gravitational-wave signals in theGWTC-1 catalog which are consistent with mergers of binary black hole systems,and perform a thorough parameter estimation re-analysis. This is made possibleby using computationally efficient waveform models of the current (fourth)generation of the IMRPhenom family of phenomenological waveform models, whichconsists of the IMRPhenomX frequency-domain modelsand the IMRPhenomTtime-domain models. The analysis is performed with both precessing andnon-precessing waveform models with and without subdominant spherical harmonicmodes. Results for all events are validated with convergence tests, discussingin particular the events GW170729 and GW151226. For the latter and the othertwo lowest-mass events, we also compare results between two independentsampling codes, Bilby and LALInference. We find overall consistent results withthe original GWTC-1 results, with all Jensen-Shannon divergences between theprevious results using IMRPhenomPv2 and our default IMRPhenomXPHM posteriorsbelow 0.045 bits, but we also discuss cases where including subdominantharmonics and/or precession influences the posteriors.<br

New twists in compact binary waveform modeling: A fast time-domain model for precession

We present IMRPhenomTPHM, a phenomenological model for the gravitational wave signals emitted by the coalescence of quasi-circular precessing binary black holes systems. The model is based on the "twisting up" approximation, which maps non-precessing signals to precessing ones in terms of a time dependent rotation described by three Euler angles, and which has been utilized in several frequency domain waveform models that have become standard tools in gravitational wave data analysis. Our model is however constructed in the time domain, which allows several improvements over the frequency domain models: we do not use the stationary phase approximation, we employ a simple approximation for the precessing Euler angles for the ringdown signal, and we implement a new method for computing the Euler angles through the evolution of the spin dynamics of the system, which is more accurate and also computationally efficient

A detailed analysis of GW190521 with phenomenological waveform models

In this paper we present an extensive analysis of the GW190521 gravitational wave event with the current (fourth) generation of phenomenological waveform models for binary black hole coalescences. GW190521 stands out from other events since only a few wave cycles are observable. This leads to a number of challenges, one being that such short signals are prone to not resolve approximate waveform degeneracies, which may result in multi-modal posterior distributions. The family of waveform models we use includes a new fast time-domain model IMRPhenomTPHM, which allows us extensive tests of different priors and robustness with respect to variations in the waveform model, including the content of spherical harmonic modes. We clarify some issues raised in a recent paper [Nitz&Capano], associated with possible support for a high-mass ratio source, but confirm their finding of a multi-modal posterior distribution, albeit with important differences in the statistical significance of the peaks. In particular, we find that the support for both masses being outside the PISN mass-gap, and the support for an intermediate mass ratio binary are drastically reduced with respect to what Nitz&Capano found. We also provide updated probabilities for associating GW190521 to the potential electromagnetic counterpart from ZTF

The morphology and clinical importance of the axillary arch

The axillary arch is the main variation of the axillary muscle. It was first described by Ramsay in 1795. In its classical form, it arises from the latissimus dorsi muscle and extends from this towards the pectoralis major, crossing the base of the axilla and creating a close relationship with the elements of the axillary neurovascular bundle. We describe the finding of 9 axillary arches, including one case of a bilateral arrangement. We develop a searching and finding technique for the axillary arch, essential for the safe and successful development of surgical procedures in the axillary region. Knowledge of this muscle variation and the possibility of finding it during axillary procedures is crucial for lymph node staging and lymphadenectomy and is also important for differential diagnosis in compressive pathologies of the axillary vessels and brachial plexus

All-sky search for continuous gravitational waves from isolated neutron stars in the early O3 LIGO data

Abbott, R. (LIGO Scientific Collaboration, Virgo Collaboration, KAGRA Collaboration)We report on an all-sky search for continuous gravitational waves in the frequency band 20-2000 Hz and with a frequency time derivative in the range of [-1.0,+0.1]×10-8 Hz/s. Such a signal could be produced by a nearby, spinning and slightly nonaxisymmetric isolated neutron star in our Galaxy. This search uses the LIGO data from the first six months of Advanced LIGO's and Advanced Virgo's third observational run, O3. No periodic gravitational wave signals are observed, and 95% confidence-level (C.L.) frequentist upper limits are placed on their strengths. The lowest upper limits on worst-case (linearly polarized) strain amplitude h0 are ∼1.7×10-25 near 200 Hz. For a circularly polarized source (most favorable orientation), the lowest upper limits are ∼6.3×10-26. These strict frequentist upper limits refer to all sky locations and the entire range of frequency derivative values. For a population-averaged ensemble of sky locations and stellar orientations, the lowest 95% C.L. upper limits on the strain amplitude are ∼1.4×10-25. These upper limits improve upon our previously published all-sky results, with the greatest improvement (factor of ∼2) seen at higher frequencies, in part because quantum squeezing has dramatically improved the detector noise level relative to the second observational run, O2. These limits are the most constraining to date over most of the parameter space searched.This work was supported by MEXT, JSPS Leading-edge Research Infrastructure Program, JSPS Grant-in-Aid for Specially Promoted Research 26000005, JSPS Grant-in-Aid for Scientific Research on Innovative Areas 2905: JP17H06358, JP17H06361 and JP17H06364, JSPS Core-to-Core Program A. Advanced Research Networks, JSPS Grant-in-Aid for Scientific Research (S) 17H06133, the joint research program of the Institute for Cosmic Ray Research, University of Tokyo, National Research Foundation (NRF) and Computing Infrastructure Project of KISTI-GSDC in Korea, Academia Sinica (AS), AS Grid Center (ASGC) and the Ministry of Science and Technology (MoST) in Taiwan under grants including ASCDA-105-M06, Advanced Technology Center (ATC) of NAOJ, and Mechanical Engineering Center of KE

BETs: Propellant less de orbiting of space debris by bare electrodynamic tethers

As a fundamental contribution to limiting the increase of debris in the Space environment, a three-year project started on 1 November 2010 financed by the European Commission under the FP-7 Space Programme. It aims at developing a universal system to be carried on board future satellites launched into low Earth orbit (LEO), to allow de-orbiting at end of life. The operational system involves a conductive tape-tether left bare of insulation to establish anodic contact with the ambient plasma as a giant Langmuir probe. The project will size the three disparate dimensions of a tape for a selected de-orbit mission and determine scaling laws to allow system design for a general mission. It will implement control laws to restrain tether dynamics in/off the orbital plane; and will carry out plasma chamber measurements and numerical simulations of tether-plasma interaction. The project also involves the design and manufacturing of subsystems: electron-ejecting plasma contactors, an electric control and power module, interface elements, tether and deployment mechanisms, tether tape/end-mass as well as current collection plus free-fall, and hypervelocity impact tests

Marine megafauna niche coexistence and hotspot areas in a temperate ecosystem

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Propellantless de orbiting of space debris by bare electrodynamic tethers

A 3-year Project started on November 1 2010, financed by the European Commision within the FP-7 Space Program, and aimed at developing an efficient de-orbit system that could be carried on board by future spacecraft launched into LEO, will be presented. The operational system will deploy a thin uninsulated tape-tether to collect electrons as a giant Langmuir probe, using no propellant/no power supply, and generating power on board. This project will involve free-fall tests, and laboratory hypervelocity-impact and tether-current tests, and design/Manufacturing of subsystems: interface elements, electric control and driving module, electron-ejecting plasma contactor, tether-deployment mechanism/end-mass, and tape samples. Preliminary results to be presented involve: i) devising criteria for sizing the three disparate tape dimensions, affecting mass, resistance, current-collection, magnetic self-field, and survivability against debris itself; ii) assessing the dynamical relevance of tether parameters in implementing control laws to limit oscillations in /off the orbital plane, where passive stability may be marginal; iii) deriving a law for bare-tape current from numerical simulations and chamber tests, taking into account ambient magnetic field, ion ram motion, and adiabatic electron trapping; iv) determining requirements on a year-dormant hollow cathode under long times/broad emission-range operation, and trading-off against use of electron thermal emission; v) determining requirements on magnetic components and power semiconductors for a control module that faces high voltage/power operation under mass/volume limitations; vi) assessing strategies to passively deploy a wide conductive tape that needs no retrieval, while avoiding jamming and ending at minimum libration; vii) evaluating the tape structure as regards conductive and dielectric materials, both lengthwise and in its cross-section, in particular to prevent arcing in triple-point junctions

Long-term benefits of nevirapine-containing regimens: multicenter study with 506 patients, followed-up a median of 9 years

[Abstract] OBJECTIVE: To evaluate long-term outcomes in patients maintaining a nevirapine (NVP)-based regimen. METHODS: Retrospective, multicenter, cohort study including patients currently receiving an NVP regimen that had been started at least 5 years previously. Demographic, clinical, and analytical variables were recorded. RESULTS: Median follow-up was 8.9 (5.7-11.3) years. Baseline characteristics: 74% men, 47 years old, 36% drug users, 40% AIDS, 40% HCV+, 51.4% detectable HIV-1 viral load, CD4 count 395 (4-1,421)/μL, 19% CD4 3.37 mmol/L significantly decreased in a subsample with available values. A significant decrease in transaminases, alkaline phosphatase, and Fib4 score was observed, mainly in HCV+ and ARV-naive patients. CONCLUSIONS: In patients who tolerate NVP therapy, (even those with HCV coinfection), long term benefits may be significant in terms of a progressive improvement in general health status markers and CD4 response, a favorable lipid profile, and good liver tolerability