1,514 research outputs found
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
Flight delays in Germany: a model for evaluation of future cost risk
Air traffic has been increasing in Germany over the last decades reaching in 2018 an all-time high with more than 3 million flights. This increase has led to a rise in delays, which generate different costs to airlines, passengers, and Air Navigation Service Providers. This paper focuses on understanding and predicting these costs. For this purpose, a stochastic modelling method is proposed to estimate future air traffic, delays and the cost of future delays. The model allows to better understand what the full distribution of the delay costs may look like. To that end, the paper analyses 1,826 daily items (from 1/1/2014 to 12/31/2018) with information of air traffic and delays for German airspace. Findings suggest that overall mean delay costs for 2019 may be up to 280 million €, while in the 5% worst cases this value could go up to an average of 319 million €. © 2022 Luis Mª Abadie, Ibon Galarraga, Itziar Ruiz-Gauna.This research is supported by the Basque Government through the BERC 2018-2021 program and by the Spanish Ministry of Economy and Competitiveness MINECO through BC3 MarÃa de Maeztu excellence accreditation MDM-2017-0714
Train Like an Astronaut Educational Outreach
In an effort to reduce the incidence of childhood obesity, the National Aeronautics and Space Administration (NASA), capitalizing on the theme of human spaceflight developed two educational outreach programs for children ages 8-12. To motivate young "fit explorers," the Train Like an Astronaut National (TLA) program and the Mission X: Train Like an Astronaut International Fitness Challenge (MX) were created. Based on the astronauts' physical training, these programs consist of activities developed by educators and experts in the areas of space life sciences and fitness. These Activities address components of physical fitness. The educational content hopes to promote students to pursue careers in science, technology, engineering, and math (STEM) fields. At the national level, in partnership with First Lady Michelle Obama's Let?s Move! Initiative, the TLA program consists of 10 physical and 2 educational activities. The program encourages families, schools, and communities to work collaboratively in order to reinforce in children and their families the importance of healthy lifestyle habits In contrast, the MX challenge is a cooperative outreach program involving numerous space agencies and other international partner institutions. During the six-week period, teams of students from around the world are challenged to improve their physical fitness and collectively accumulate points by completing 18 core activities. During the 2011 pilot year, a t otal of 137 teams and more than 4,000 students from 12 countries participated in the event. MX will be implemented within 24 countries during the 2012 challenge. It is projected that 7,000 children will "train like an astronaut"
Calibration of the LIGO displacement actuators via laser frequency modulation
We present a frequency modulation technique for calibration of the
displacement actuators of the LIGO 4-km-long interferometric gravitational-wave
detectors. With the interferometer locked in a single-arm configuration, we
modulate the frequency of the laser light, creating an effective length
variation that we calibrate by measuring the amplitude of the frequency
modulation. By simultaneously driving the voice coil actuators that control the
length of the arm cavity, we calibrate the voice coil actuation coefficient
with an estimated 1-sigma uncertainty of less than one percent. This technique
enables a force-free, single-step actuator calibration using a displacement
fiducial that is fundamentally different from those employed in other
calibration methods.Comment: 10 pages, 5 figures, submitted to Classical and Quantum Gravit
Insights on the economic estimates of the climate costs of the aviation sector due to air management in 2018-19
Air navigation service providers ensure that aircrafts keep safely apart by prescribing vertical and horizontal distances to each other. In the European Union and its associated members, regulation is carried out via a performance scheme which measures and sets targets for the different key performance areas. For the environmental area, targets in terms of CO2 and other pollutants were set by assuming that there would be continuous improvements for the Key performance Environment indicator based on actual trajectory. However, although a higher Horizontal Flight Efficiency (HFE) measurement usually means a more direct flight trajectory, this does not necessarily translate into a climate optimal trajectory. Thus, vertical flight efficiency also needs to be considered. There is also an interdependency between airspace and Air Traffic Management Capacity and Environment: when the offered capacity falls short of the demand for flights, ground delays, holdings and traffic shifts to adjacent areas occur. This entails detours and a deterioration of the HFE-indicator. Results show that total climate costs for 2018 and 2019 may be as high as 1 bn EUR, of which about 34% is due to CO2 emissions. In particular, the climate costs of CO2 emissions due to capacity constraints range from 54 to 301 million EUR, depending on whether CO2 costs are measured in terms of avoidance costs or under the EU Emissions Trading System (EU ETS). Following the first criterion and the short to medium run up to 2030, the estimated costs would amount to 112 million EUR. In the long run, from 2040 to 2060, these costs would amount to 301 Million EUR. With the estimates of the EU ETS, the cost by 2030 would be close to 54 million EUR and 153.5 million EUR for the long run. Volatility of carbon pricing may play a very significant role, but fortunately can be hedged. Therefore, a shortfall of capacity leads to delay costs and considerable environmental costs. As capacity is planned in the medium to long-term, traffic forecasts are a crucial element. This means that further research is warranted into the interdependency of traffic forecasts, capacity and environmental costs. © 2021 Publicaciones Dyna Sl. All rights reserved.This research is supported by the Basque Government through the BERC 2018-2021 programme and by the Spanish Ministry of Economy and Competitiveness (MINECO) through BC3 MarÃa de Maeztu excellence accreditation MDM-2017-0714. Further support is provided by the project MINECO RTI 2018-093352-B-I00
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
Sea-level rise in the Basque coast, A probabilistic approach
Itsas mailaren gorakada aldaketa klimatikoaren mehatxu garrantzitsuenetarikoa da euskal kostaldearentzat. Artikulu honetan itsas-mailaren bataz besteko igoeraren esperotako balioa zenbatetsi dugu hamaika herritan, hiru isurpen-egoeratan. Probabilitate txikiko baina magnitude handiko gertaerak deskribatzen dituzten bi arrisku neurketa ere zenbatesten dira. 2050. urterako gure emaitzek 21-29cm arteko bataz besteko igoerak iradokitzen dituzte, eta muturreko balio askoz handiagoak, 35-45cm 95 pertzentilerako eta 40-52cm kasu okerrenen %5aren bataz bestekoarentzako. Informazio hori oso esanguratsua izan daiteke klima aldaketaren egokitzapenerako politiken garapenean. Izan ere, arriskuaren kudeaketa egokiago bat ahalbidetzen du eta lerrokaturik baitago finantza ekonomikoan erabilitako hurbilpenekin. © 2018, Ekonomiaz, Basque Economics Journal.Due to climate change, sea-level rise poses a major threat to the Basque coast. In this study we assess the average sea-level rise under three emission scenarios in eleven municipalities of the Basque coast. We also estimate two risk measures that describe low-probability, highdamage events. Our results by 2050 show average sea-level increases in 21-29 cm and significantly larger extreme values, ranging between 35 and 45 cm at the 95th percentile and 40-52 cm at the average of 5% worst cases. This information could be very relevant to inform climate change adaptation policies and measures, as it allows managing risk more effectively, in line with the approaches used in financial economics. © 2018, Ekonomiaz, Basque Economics Journal.El aumento del nivel del mar representa una de las principales amenazas del cambio climático para la costa vasca. En este artÃculo estimamos el valor medio esperado de aumento del nivel del mar en once localidades bajo tres escenarios de emisión, junto con dos medidas de riesgo que describen aquellos eventos de baja probabilidad pero de gran magnitud. Nuestros resultados para el año 2050 sugieren aumentos medios de entre 21-29 cm y valores extremos significativamente mayores, de 35-45 cm para el percentil 95 y de 40-52 cm para la media del 5% de los peores casos. Esta información puede ser muy relevante para el desarrollo de polÃticas de adaptación al cambio climático ya que permite una gestión del riesgo más adecuada, en lÃnea con las aproximaciones empleadas desde la economÃa financiera. © 2018, Ekonomiaz, Basque Economics Journal
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