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

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

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

Search for Tensor, Vector, and Scalar Polarizations in the Stochastic Gravitational-Wave Background

The detection of gravitational waves with Advanced LIGO and Advanced Virgo has enabled novel tests of general relativity, including direct study of the polarization of gravitational waves. While general relativity allows for only two tensor gravitational-wave polarizations, general metric theories can additionally predict two vector and two scalar polarizations. The polarization of gravitational waves is encoded in the spectral shape of the stochastic gravitational-wave background, formed by the superposition of cosmological and individually unresolved astrophysical sources. Using data recorded by Advanced LIGO during its first observing run, we search for a stochastic background of generically polarized gravitational waves. We find no evidence for a background of any polarization, and place the first direct bounds on the contributions of vector and scalar polarizations to the stochastic background. Under log-uniform priors for the energy in each polarization, we limit the energy densities of tensor, vector, and scalar modes at 95% credibility to Ω0T<5.58×10-8, Ω0V<6.35×10-8, and Ω0S<1.08×10-7 at a reference frequency f0=25 Hz. © 2018 American Physical Society

Search for Gravitational Waves from Intermediate Mass Binary Black Holes

We present the results of a weakly modeled burst search for gravitational waves from mergers of non-spinning intermediate mass black holes (IMBH) in the total mass range 100--450 solar masses and with the component mass ratios between 1:1 and 4:1. The search was conducted on data collected by the LIGO and Virgo detectors between November of 2005 and October of 2007. No plausible signals were observed by the search which constrains the astrophysical rates of the IMBH mergers as a function of the component masses. In the most efficiently detected bin centered on 88+88 solar masses, for non-spinning sources, the rate density upper limit is 0.13 per Mpc^3 per Myr at the 90% confidence level.Comment: 13 pages, 4 figures: data for plots and archived public version at https://dcc.ligo.org/cgi-bin/DocDB/ShowDocument?docid=62326, see also the public announcement at http://www.ligo.org/science/Publication-S5IMBH

On the progenitor of binary neutron star merger GW170817

On 2017 August 17 the merger of two compact objects with masses consistent with two neutron stars was discovered through gravitational-wave (GW170817), gamma-ray (GRB 170817A), and optical (SSS17a/AT 2017gfo) observations. The optical source was associated with the early-type galaxy NGC 4993 at a distance of just ∼40 Mpc, consistent with the gravitational-wave measurement, and the merger was localized to be at a projected distance of ∼2 kpc away from the galaxy's center. We use this minimal set of facts and the mass posteriors of the two neutron stars to derive the first constraints on the progenitor of GW170817 at the time of the second supernova (SN). We generate simulated progenitor populations and follow the three-dimensional kinematic evolution from binary neutron star (BNS) birth to the merger time, accounting for pre-SN galactic motion, for considerably different input distributions of the progenitor mass, pre-SN semimajor axis, and SN-kick velocity. Though not considerably tight, we find these constraints to be comparable to those for Galactic BNS progenitors. The derived constraints are very strongly influenced by the requirement of keeping the binary bound after the second SN and having the merger occur relatively close to the center of the galaxy. These constraints are insensitive to the galaxy's star formation history, provided the stellar populations are older than 1 Gyr

THE SANDIA X-RAY LASER PROGRAM

Le laser au rayon X en train d'être développé aux Laboratoires Sandia utilise un rayonnement keV intense, produit par la compression cylindrique ("Z-pinch") d'une bouffée de gaz, pour obtenir les ions de la série isoélectronique F par la photoionisation des ions Ne. Les populations des niveaux de la configuration (2p)5(3p) et de la configuration (2p)5(3s) sont inverties par des processus de recombinaison des ions. Une enveloppe annulaire de stagnation maintient la séparation entre la source du rayonnement et le plasma étant lasé. Une couche mince d'aluminium ou sodium sert pour changer la longueur d'onde du rayonnement. La méthode pour arriver aux dimensions et à la densité du laser au rayon X est décrite.The Sandia X-ray Laser Program is based on the use of intense keV radiation produced by gas puff, Z-pinch implosions to photoionize Ne-like ions to F-like ions. A 3p-3s population inversion is generated via recombination processes. An annular stagnation shell is used to separate the imploding pump source from the lasant. We are also developing a converter technology for examining the Na-Ne line matching scheme. Design considerations and some computational results are presented

Z-PINCH IMPLOSION DRIVEN X-RAY LASER RESEARCH

In experiments performed during the past two years on Proto II (a 10-TW pulsed-power accelerator), we imploded annular plasmas onto thin-walled annular x-ray laser targets in order to create a radiation pump source for x-ray laser physics studies. This Z-pinch must be axially uniform and must efficiently produce the pump radiation without destroying the laser medium on the cylindrical axis of symmetry. To characterize the pump source x-rays and lasant conditions, we regularly field a large number of x-ray diagnostics. In recent experiments, we produced over 15 kJ of ≥1-keV pump radiation with an imploding neon gas-puff load. We are considering both recombination and resonance-pumped x-ray laser schemes

Early statin initiation and outcomes in patients with acute coronary syndromes.

Item does not contain fulltextCONTEXT: The secondary prevention benefit of therapy with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) has been clearly demonstrated; however, the role of early initiation of statins after acute coronary syndromes (ACSs) is unknown. OBJECTIVE: To evaluate the association of early statin initiation (< or = 7 days) after ACS with 90-day and 1-year outcomes. DESIGN: Observational cohort from databases of 2 randomized clinical trials, SYMPHONY and 2nd SYMPHONY. SETTING: Nine hundred thirty-one clinical centers in 37 countries. PATIENTS: A total of 12,365 ACS patients randomized from August 1997 to August 1999 who were not taking statins prior to the index ACS and who either started statin therapy early (median, 2.0 [interquartile range, 1.0-3.1] days after ACS; n = 3952) or survived more than 5 days after ACS and never received statin therapy (n = 8413). MAIN OUTCOME MEASURES: Ninety-day incidence of death; death or myocardial infarction (MI); and death, MI, or severe recurrent ischemia; as well as 1-year incidence of death. RESULTS: Ninety-day and 1-year unadjusted mortality comparison suggested early statin benefit (1.2% for early statins vs 2.1% for no statins; hazard ratio [HR], 0.58; 95% confidence interval [CI], 0.42-0.81 for 90-day comparisons and 2.3% for early statins vs 4.4% for no statins; HR, 0.52; 95% CI, 0.40-0.68 for 1-year comparison). However, no benefit was evident for 90-day death or MI (6.5% vs 6.9%; HR, 0.95; 95% CI, 0.82-1.11) or death, MI, or severe recurrent ischemia (9.2% vs 8.9%; HR, 1.04; 95% CI, 0.92-1.18). After propensity and covariate adjustment, there were no 90-day or 1-year differences between the early-statin group and the no-statin group. The 90-day adjusted HR for death was 1.08 (95% CI, 0.75-1.56); for death or MI, 1.08 (95% CI, 0.91-1.29); and for death, MI, or severe recurrent ischemia, 1.15 (95% CI, 0.99-1.34). One-year mortality-adjusted HR was 0.99 (95% CI, 0.73-1.33). Among 2711 patients with core laboratory lipid analysis, early statin was associated with higher adjusted risk for death or death or MI at cholesterol levels below treatment guidelines but was more favorable at higher levels. CONCLUSIONS: In this study, there was no relationship between early initiation of statin therapy and improved outcomes although our subset analysis suggests that outcomes after early statin initiation may vary with cholesterol levels. Confirmation of early treatment effects of statins on outcomes awaits the results of adequately powered randomized clinical trials