Electromagnetic follow-up of gravitational wave transient signal candidates

Pioneering efforts aiming at the development of multi-messenger gravitational wave and electromagnetic astronomy have been made. An electromagnetic observation follow-up program of candidate gravitational wave events has been performed (Dec 17 2009 to Jan 8 2010 and Sep 4 to Oct 20 2010) during the recent runs of the LIGO and Virgo gravitational wave detectors. It involved ground-based and space electromagnetic facilities observing the sky at optical, X-ray and radio wavelengths. The joint gravitational wave and electromagnetic observation study requires the development of specific image analysis procedures able to discriminate the possible electromagnetic counterpart of gravitational wave triggers from contaminant/background events. The paper presents an overview of the electromagnetic follow-up program and the image analysis procedures.Comment: Proceedings of the 12th International Conference on "Topics in Astroparticle and Underground Physics" (TAUP 2011), Munich, September 2011 (to appear in IoP Journal of Physics: Conference Series

“Un poder Transformador”. Creatividad y habilidades de pensamiento que nutren la experimentación de nuevas ideas sustentables”

Si partimos de preguntas tales como: ¿Qué vale la pena enseñar?, ¿Cómo las habilidades de pensamiento promueven prácticas que conducen a la sostenibilidad ambiental y la revitalización?, ¿Cómo promovemos el desarrollo de habilidades de pensamiento que conduzcan al uso del conocimiento, la tecnología y la innovación para promover la sostenibilidad y la revitalización? Como docentes debemos introducir desafíos en contextos adecuados para así generar en los alumnos nuevas ideas. Tanto la creatividad como el pensamiento crítico son procesos que se nutren con la experimentación de ideas. Ellas pueden surgir a través de una acción, un relato, una imagen, un tópico o un juego. Visualizando al auditorio en una serie de estrategias que siguen una secuencia de desempeños, se evidenciara habilidades tales como: sintetizar, tomar riesgos, razonar con evidencia, describir, asumir roles, trabajar colaborativa mente y generar ideas

Evaluation of the presence of the bap gene in Staphylococcus aureus isolates recovered from human and animals species.

International audienceThe implication of biofilm in chronic bacterial infection in many species has triggered an increasing interest in the characterization of genes involved in biofilm formation. The bap gene is a newly identified gene that encodes the biofilm-associated protein, BAP, which is involved in biofilm formation in Staphylococcus aureus. So far the bap gene has only been found in a small proportion of S. aureus strains from bovine mastitis in Spain. In order to study the presence of the bap gene in S. aureus isolates obtained from other species and various locations, a collection of 262 isolates was tested by PCR, using published primers and dot-blot. The results indicated that none of the isolates carried the bap gene suggesting that the prevalence of this gene among S. aureus isolates should be very low

A blind hierarchical coherent search for gravitational-wave signals from coalescing compact binaries in a network of interferometric detectors

We describe a hierarchical data analysis pipeline for coherently searching for gravitational wave (GW) signals from non-spinning compact binary coalescences (CBCs) in the data of multiple earth-based detectors. It assumes no prior information on the sky position of the source or the time of occurrence of its transient signals and, hence, is termed "blind". The pipeline computes the coherent network search statistic that is optimal in stationary, Gaussian noise, and allows for the computation of a suite of alternative statistics and signal-based discriminators that can improve its performance in real data. Unlike the coincident multi-detector search statistics employed so far, the coherent statistics are different in the sense that they check for the consistency of the signal amplitudes and phases in the different detectors with their different orientations and with the signal arrival times in them. The first stage of the hierarchical pipeline constructs coincidences of triggers from the multiple interferometers, by requiring their proximity in time and component masses. The second stage follows up on these coincident triggers by computing the coherent statistics. The performance of the hierarchical coherent pipeline on Gaussian data is shown to be better than the pipeline with just the first (coincidence) stage.Comment: 12 pages, 3 figures, accepted for publication in Classical and Quantum Gravit

Beating the Spin-Down Limit on Gravitational Wave Emission from the Vela Pulsar

We present direct upper limits on continuous gravitational wave emission from the Vela pulsar using data from the Virgo detector\u27s second science run. These upper limits have been obtained using three independent methods that assume the gravitational wave emission follows the radio timing. Two of the methods produce frequentist upper limits for an assumed known orientation of the star\u27s spin axis and value of the wave polarization angle of, respectively, 1.9\ee{-24} and 2.2\ee{-24}, with 95% confidence. The third method, under the same hypothesis, produces a Bayesian upper limit of 2.1\ee{-24}, with 95% degree of belief. These limits are below the indirect {\it spin-down limit} of 3.3\ee{-24} for the Vela pulsar, defined by the energy loss rate inferred from observed decrease in Vela\u27s spin frequency, and correspond to a limit on the star ellipticity of $\sim 10^{-3}$. Slightly less stringent results, but still well below the spin-down limit, are obtained assuming the star\u27s spin axis inclination and the wave polarization angles are unknown

Risk measures and the distribution of damage curves for 600 European coastal cities

A good understanding of climate change damages is vital to design effective adaptation policies and measures. Using a dataset of probabilistic sea-level rise and other of flood damages and protection cost curves for the 600 largest European coastal cities we generate stochastic damage curves and their distributions with and without adaptation. We apply the Generalized Extreme Value distribution to characterize the distributions and calculate two risk measures: the Value at Risk and the Expected Shortfall, which contribute to understanding the magnitude and probability of high-end sea-level rise represented by the upper tail of the distribution. This allows the costs of sea-level rise to be estimated (that is, in addition to other costs related to coastal extreme events) and supports decision-makers in integrating the high uncertainty related to future projections. This knowledge is necessary for an adequate risk management that does not underestimate risk. Furthermore, it allows city planners to tailor their risk tolerance. A great number of cities in Europe are currently undertaking adaptation plans or have already done so. Making these findings available should therefore be of great priority value to inform these processes. © 2019 The Author(s). Published by IOP Publishing Ltd.This research is supported by the Basque Government through the BERC 2018–2021 program and by the Spanish Ministry of Science, Innovation and Universities (MICINN) through BC3’s María de Maeztu excellence accreditation MDM-2017-0714

Search for Gravitational Waves from Binary Black Hole Inspiral, Merger and Ringdown

We present the first modeled search for gravitational waves using the complete binary black hole gravitational waveform from inspiral through the merger and ringdown for binaries with negligible component spin. We searched approximately 2 years of LIGO data taken between November 2005 and September 2007 for systems with component masses of 1-99 solar masses and total masses of 25-100 solar masses. We did not detect any plausible gravitational-wave signals but we do place upper limits on the merger rate of binary black holes as a function of the component masses in this range. We constrain the rate of mergers for binary black hole systems with component masses between 19 and 28 solar masses and negligible spin to be no more than 2.0 per Mpc^3 per Myr at 90% confidence

An all-sky search algorithm for continuous gravitational waves from spinning neutron stars in binary systems

Rapidly spinning neutron stars with non-axisymmetric mass distributions are expected to generate quasi-monochromatic continuous gravitational waves. While many searches for unknown, isolated spinning neutron stars have been carried out, there have been no previous searches for unknown sources in binary systems. Since current search methods for unknown, isolated neutron stars are already computationally limited, expanding the parameter space searched to include binary systems is a formidable challenge. We present a new hierarchical binary search method called TwoSpect, which exploits the periodic orbital modulations of the continuous waves by searching for patterns in doubly Fourier-transformed data. We will describe the TwoSpect search pipeline, including its mitigation of detector noise variations and corrections for Doppler frequency modulation caused by changing detector velocity. Tests on Gaussian noise and on a set of simulated signals will be presented.Comment: 22 pages, 10 figures, 1 table, Submitted to Classical and Quantum Gravit