1,500 research outputs found
Designing a template bank to observe compact binary coalescences in Advanced LIGO's second observing run
We describe the methodology and novel techniques used to construct a set of
waveforms, or template bank, applicable to searches for compact binary
coalescences in Advanced LIGO's second observing run. This template bank is
suitable for observing systems composed of two neutron stars, two black holes,
or a neutron star and a black hole. The Post-Newtonian formulation is used to
model waveforms with total mass less than 4 and the most recent
effective-one-body model, calibrated to numerical relativity to include the
merger and ringdown, is used for total masses greater than 4 . The
effects of spin precession, matter, orbital eccentricity and radiation modes
beyond the quadrupole are neglected. In contrast to the template bank used to
search for compact binary mergers in Advanced LIGO's first observing run, here
we are including binary-black-hole systems with total mass up to several
hundreds of solar masses, thereby improving the ability to observe such
systems. We introduce a technique to vary the starting frequency of waveform
filters so that our bank can simultaneously contain binary-neutron-star and
high-mass binary-black hole waveforms. We also introduce a lower-bound on the
filter waveform length, to exclude very short-duration, high-mass templates
whose sensitivity is strongly reduced by the characteristics and performance of
the interferometers.Comment: 10 pages, 8 figure
Efficient searches for spinning compact binaries with advanced gravitational-wave observatories
[no abstract
Carlo Sbisà alle Biennali di Venezia tra le due guerre
From 1922 to 1936 Carlo Sbisà is an assiduous exhibitor at the Venice Biennali.
The artist begins his career precociously (he is little more than twenty), exhibiting works engraved during his Florentine period: a dry-point portrait at the 1922
Biennale and two etchings, also portraits, at the 1924 Biennale. More and more,
at the following Biennali, Sbisà makes a name for himself as a painter perfectly
in keeping with the character of “Novecento italiano”, not without some trace
of Magic realism: from Elisabetta and Maria and Female Portrait, oil paintings exhibited
in 1926, to The Astronomers, oil painting exhibited in 1936, the paintings
of the Trieste-born artist – mostly painted with a steady brush-stroke, without
indulging to any impressionistic suggestions – grant the human figure a central
position, while perfectly setting it in an architectural or landscape context. At
the 1948 Biennale Sbisà will again exhibit a couple of paintings, in a very distant
style, though, from the works of his previous period: in consonance with the
changes of the postwar years, they seem to definitively confirm the end of that
“Novecento” of which the artist has been an exemplary representative, much appreciated
by the criticism of his time
Políticas públicas, planejamento e desenvolvimento econômico: um estudo de caso do município de Seberi/RS
TCC(graduação) - Universidade Federal de Santa Catarina. Centro Socioeconômico. Ciências Econômicas (EaD).No trabalho discute-se o papel e a influência da ação do governo municipal no processo de desenvolvimento econômico local, como articulador na dinâmica da reorganização das políticas públicas direcionadas ao crescimento de sua economia. Haja visto, que dentro das metas de governo o planejamento busca desenvolver as potencialidades municipais no caminho da geração de emprego e renda para a população local, bem como uma maior participação na economia regional. Para que isso aconteça é necessário um maior acompanhamento dos programas de trabalho traçados no planejamento de médio prazo, buscando unir flexibilidade e adequação necessária no processo de monitoramento da gestão, buscando enfrentar certas deficiências e suprir novas demandas da sociedade local. Dentro deste marco, o objetivo deste trabalho é realizar uma análise conceitual e financeira do programa de trabalho da gestão 2010/2013 do PPA - Plano Plurianual do município de Seberi RS
PyCBC Live: Rapid Detection of Gravitational Waves from Compact Binary Mergers
We introduce an efficient and straightforward technique for rapidly detecting
gravitational waves from compact binary mergers. We show that this method
achieves the low latencies required to alert electromagnetic partners of
candidate binary mergers, aids in data monitoring, and makes use of
multidetector networks for sky localization. This approach was instrumental to
the analysis of gravitational-wave candidates during the second observing run
of Advanced LIGO, including the period of coincident operation with Advanced
Virgo, and in particular the analysis of the first observed binary neutron star
merger GW170817, where it led to the first tightly localized sky map
() used to identify AT 2017gfo. Operation of this analysis
also enabled the initial discovery of GW170104 and GW170608 despite non-nominal
observing of the instrument.Comment: 10 pages, 5 figures, submitted to Physical Review
Designing a template bank to observe compact binary coalescences in Advanced LIGO's second observing run
We describe the methodology and novel techniques used to construct a set of waveforms, or template bank, applicable to searches for compact binary coalescences in Advanced LIGO's second observing run. This template bank is suitable for observing systems composed of two neutron stars, two black holes, or a neutron star and a black hole. The Post-Newtonian formulation is used to model waveforms with total mass less than 4 and the most recent effective-one-body model, calibrated to numerical relativity to include the merger and ringdown, is used for total masses greater than 4 . The effects of spin precession, matter, orbital eccentricity and radiation modes beyond the quadrupole are neglected. In contrast to the template bank used to search for compact binary mergers in Advanced LIGO's first observing run, here we are including binary-black-hole systems with total mass up to several hundreds of solar masses, thereby improving the ability to observe such systems. We introduce a technique to vary the starting frequency of waveform filters so that our bank can simultaneously contain binary-neutron-star and high-mass binary-black hole waveforms. We also introduce a lower-bound on the filter waveform length, to exclude very short-duration, high-mass templates whose sensitivity is strongly reduced by the characteristics and performance of the interferometers
Electromagnetic Chirps from Neutron Star-Black Hole Mergers
We calculate the electromagnetic signal of a gamma-ray flare coming from the
surface of a neutron star shortly before merger with a black hole companion.
Using a new version of the Monte Carlo radiation transport code Pandurata that
incorporates dynamic spacetimes, we integrate photon geodesics from the neutron
star surface until they reach a distant observer or are captured by the black
hole. The gamma-ray light curve is modulated by a number of relativistic
effects, including Doppler beaming and gravitational lensing. Because the
photons originate from the inspiraling neutron star, the light curve closely
resembles the corresponding gravitational waveform: a chirp signal
characterized by a steadily increasing frequency and amplitude. We propose to
search for these electromagnetic chirps using matched filtering algorithms
similar to those used in LIGO data analysis.Comment: 13 pages, 5 figures, submitted to Ap
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