Showing papers by "R. Flaminio published in 2013"
TL;DR: In this paper, the authors present the current best estimate of the plausible observing scenarios for the Advanced LIGO, Advanced Virgo and KAGRA detectors over the next several years, with the intention of providing information to facilitate planning for multi-messenger astronomy with gravitational waves.
Abstract: We present our current best estimate of the plausible observing scenarios for the Advanced LIGO, Advanced Virgo and KAGRA gravitational-wave detectors over the next several years, with the intention of providing information to facilitate planning for multi-messenger astronomy with gravitational waves. We estimate the sensitivity of the network to transient gravitational-wave signals for the third (O3), fourth (O4) and fifth observing (O5) runs, including the planned upgrades of the Advanced LIGO and Advanced Virgo detectors. We study the capability of the network to determine the sky location of the source for gravitational-wave signals from the inspiral of binary systems of compact objects, that is BNS, NSBH, and BBH systems. The ability to localize the sources is given as a sky-area probability, luminosity distance, and comoving volume. The median sky localization area (90\% credible region) is expected to be a few hundreds of square degrees for all types of binary systems during O3 with the Advanced LIGO and Virgo (HLV) network. The median sky localization area will improve to a few tens of square degrees during O4 with the Advanced LIGO, Virgo, and KAGRA (HLVK) network. We evaluate sensitivity and localization expectations for unmodeled signal searches, including the search for intermediate mass black hole binary mergers.
536 citations
TL;DR: In this paper, a selection of simulated signals added either in hardware or software to the data collected by the two LIGO instruments and the Virgo detector during their most recent joint science run, including a "blind injection" where the signal was not initially revealed to the collaboration.
Abstract: Compact binary systems with neutron stars or black holes are one of the most promising sources for ground-based gravitational-wave detectors. Gravitational radiation encodes rich information about source physics; thus parameter estimation and model selection are crucial analysis steps for any detection candidate events. Detailed models of the anticipated waveforms enable inference on several parameters, such as component masses, spins, sky location and distance, that are essential for new astrophysical studies of these sources. However, accurate measurements of these parameters and discrimination of models describing the underlying physics are complicated by artifacts in the data, uncertainties in the waveform models and in the calibration of the detectors. Here we report such measurements on a selection of simulated signals added either in hardware or software to the data collected by the two LIGO instruments and the Virgo detector during their most recent joint science run, including a "blind injection'' where the signal was not initially revealed to the collaboration. We exemplify the ability to extract information about the source physics on signals that cover the neutron-star and black-hole binary parameter space over the component mass range 1M(circle dot)-25M(circle dot) and the full range of spin parameters. The cases reported in this study provide a snapshot of the status of parameter estimation in preparation for the operation of advanced detectors.
136 citations
TL;DR: The results of searches for gravitational waves from a large selection of pulsars using data from the most recent science runs (S6, VSR2 and VSR4) of the initial generation of interferometric gravitational wave detectors LIGO (Laser Interferometric Gravitational-wave Observatory) and Virgo as mentioned in this paper.
Abstract: We present the results of searches for gravitational waves from a large selection of pulsars using data from the most recent science runs (S6, VSR2 and VSR4) of the initial generation of interferometric gravitational wave detectors LIGO (Laser Interferometric Gravitational-wave Observatory) and Virgo. We do not see evidence for gravitational wave emission from any of the targeted sources but produce upper limits on the emission amplitude. We highlight the results from seven young pulsars with large spin-down luminosities. We reach within a factor of five of the canonical spin-down limit for all seven of these, whilst for the Crab and Vela pulsars we further surpass their spin-down limits. We present new or updated limits for 172 other pulsars (including both young and millisecond pulsars). Now that the detectors are undergoing major upgrades, and, for completeness, we bring together all of the most up-to-date results from all pulsars searched for during the operations of the first-generation LIGO, Virgo and GEO600 detectors. This gives a total of 195 pulsars including the most recent results described in this paper.
114 citations
TL;DR: In this article, the authors reported a search for gravitational waves from the inspiral, merger and ringdown of binary black holes with total mass between 25 and 100 solar masses, in data taken at the LIGO and Virgo observatories between July 7, 2009 and October 20, 2010.
Abstract: We report a search for gravitational waves from the inspiral, merger and ringdown of binary black holes (BBH) with total mass between 25 and 100 solar masses, in data taken at the LIGO and Virgo observatories between July 7, 2009 and October 20, 2010. The maximum sensitive distance of the detectors over this period for a (20, 20)M-circle dot coalescence was 300 Mpc. No gravitational wave signals were found. We thus report upper limits on the astrophysical coalescence rates of BBH as a function of the component masses for nonspinning components, and also evaluate the dependence of the search sensitivity on component spins aligned with the orbital angular momentum. We find an upper limit at 90% confidence on the coalescence rate of BBH with nonspinning components of mass between 19 and 28M(circle dot) of 3:3 x 10(-7) mergers Mpc(-3) yr(-1).
108 citations
TL;DR: In this paper, the results of an all-sky search for periodic gravitational waves in the frequency range [50, 1190] Hz and with frequency derivative range of similar to [-20, 1.1] x 10(-10) Hz s(-1) for the fifth LIGO science run (S5) are presented.
Abstract: This paper presents results of an all-sky search for periodic gravitational waves in the frequency range [50, 1190] Hz and with frequency derivative range of similar to[-20, 1.1] x 10(-10) Hz s(-1) for the fifth LIGO science run (S5). The search uses a noncoherent Hough-transform method to combine the information from coherent searches on time scales of about one day. Because these searches are very computationally intensive, they have been carried out with the Einstein@Home volunteer distributed computing project. Postprocessing identifies eight candidate signals; deeper follow-up studies rule them out. Hence, since no gravitational wave signals have been found, we report upper limits on the intrinsic gravitational wave strain amplitude h(0). For example, in the 0.5 Hz-wide band at 152.5 Hz, we can exclude the presence of signals with h(0) greater than 7.6 x 10(-25) at a 90% confidence level. This search is about a factor 3 more sensitive than the previous Einstein@Home search of early S5 LIGO data.
100 citations
Journal Article•
89 citations
TL;DR: In this article, the results of a directed search for continuous gravitational waves from unknown, isolated neutron stars in the Galactic Center region, performed on two years of data from LIGO's fifth science run from two LAS detectors, were presented.
Abstract: We present the results of a directed search for continuous gravitational waves from unknown, isolated neutron stars in the Galactic Center region, performed on two years of data from LIGO's fifth science run from two LIGO detectors. The search uses a semi-coherent approach, analyzing coherently 630 segments, each spanning 11.5 hours, and then incoherently combining the results of the single segments. It covers gravitational wave frequencies in a range from 78 to 496 Hz and a frequency-dependent range of first order spindown values down to -7.86 x 10^-8 Hz/s at the highest frequency. No gravitational waves were detected. We place 90% confidence upper limits on the gravitational wave amplitude of sources at the Galactic Center. Placing 90% confidence upper limits on the gravitational wave amplitude of sources at the Galactic Center, we reach ~3.35x10^-25 for frequencies near 150 Hz. These upper limits are the most constraining to date for a large-parameter-space search for continuous gravitational wave signals.
70 citations
TL;DR: In this article, the results of the first search for gravitational wave bursts associated with high energy neutrinos were presented, which could reveal new, hidden sources that are not observed by conventional photon astronomy, particularly at high energy.
Abstract: We present the results of the first search for gravitational wave bursts associated with high energy neutrinos. Together, these messengers could reveal new, hidden sources that are not observed by conventional photon astronomy, particularly at high energy. Our search uses neutrinos detected by the underwater neutrino telescope ANTARES in its 5 line configuration during the period January - September 2007, which coincided with the fifth and first science runs of LIGO and Virgo, respectively. The LIGO-Virgo data were analysed for candidate gravitational-wave signals coincident in time and direction with the neutrino events. No significant coincident events were observed. We place limits on the density of joint high energy neutrino - gravitational wave emission events in the local universe, and compare them with densities of merger and core-collapse events.
58 citations
TL;DR: Using the photodeflection technique, absorption as low as 5 ppm/cm has been measured on a sample with a resistivity of 10 kΩ·cm and the absorption as a function of the resistivity has been derived for n-type silicon.
Abstract: We report on the measurement of the optical absorption of bulk crystalline silicon at 1550 nm. Using the photodeflection technique, absorption as low as 5 ppm/cm has been measured on a sample with a resistivity of 10 kΩ·cm. The absorption as a function of the resistivity has been derived for n-type silicon.
43 citations
TL;DR: In this paper, the authors investigate models of long-lived GW emission associated with the accretion disk of a collapsed star or with its protoneutron star remnant, and place 90% confidence level upper limits on the GW fluence at Earth from long gamma-ray bursts for three waveforms inspired by a model of GWs from accretion disks instabilities.
Abstract: Long gamma-ray bursts (GRBs) have been linked to extreme core-collapse supernovae from massive stars. Gravitational waves (GW) offer a probe of the physics behind long GRBs. We investigate models of long-lived (~10-1000s) GW emission associated with the accretion disk of a collapsed star or with its protoneutron star remnant. Using data from LIGO's fifth science run, and GRB triggers from the swift experiment, we perform a search for unmodeled long-lived GW transients. Finding no evidence of GW emission, we place 90% confidence level upper limits on the GW fluence at Earth from long GRBs for three waveforms inspired by a model of GWs from accretion disk instabilities. These limits range from F<3.5 ergs cm^-2 to $F<1200 ergs cm^-2, depending on the GRB and on the model, allowing us to probe optimistic scenarios of GW production out to distances as far as ~33 Mpc. Advanced detectors are expected to achieve strain sensitivities 10x better than initial LIGO, potentially allowing us to probe the engines of the nearest long GRBs.
39 citations
TL;DR: Low-frequency measurements of the mechanical loss of a high-quality multilayer dielectric coating of ion-beam-sputtered fused silica and titanium-doped tantala in the 10-300 K temperature range reveal a useful parameter for the computation of coating thermal noise on different substrates as a function of temperature and frequency.
Abstract: We report on low-frequency measurements of the mechanical loss of a high-quality (transmissivity T<5 ppm at λ(0)=1064 nm, absorption loss <0.5 ppm) multilayer dielectric coating of ion-beam-sputtered fused silica and titanium-doped tantala in the 10-300 K temperature range. A useful parameter for the computation of coating thermal noise on different substrates is derived as a function of temperature and frequency.
TL;DR: It is shown that the carrier to envelop phase can have a dramatic effect even for pulses with hundreds of cycles, and is succeeded in unambiguously measuring the CEP of a 2 ps pulse train.
Abstract: We report on the first demonstration, to the best of our knowledge, of the locking of a Fabry–Perot cavity with a finesse of 28,000 in the pulsed regime. The system is based on a stable picosecond oscillator, an ultrastable cavity with high-reflection mirrors, and an all-numerical feedback system that allows efficient and independent control of the repetition rate and the pulse to pulse carrier-to-envelop phase drift (CEP). We show that the carrier to envelop phase can have a dramatic effect even for pulses with hundreds of cycles. Moreover, we have succeeded in unambiguously measuring the CEP of a 2 ps pulse train. Finally, we discuss the potential of our findings to reach the MW average power level stored in an external cavity enhancement architecture.
TL;DR: In this article, an all-sky search for periodic gravitational waves in the frequency range 50-1000 Hz with the first derivative of frequency in the range $-8.9 \times 10^{-10}$ Hz/s to zero in two years of data collected during LIGO's fifth science run.
Abstract: We report on an all-sky search for periodic gravitational waves in the frequency range $\mathrm{50-1000 Hz}$ with the first derivative of frequency in the range $-8.9 \times 10^{-10}$ Hz/s to zero in two years of data collected during LIGO's fifth science run. Our results employ a Hough transform technique, introducing a $\chi^2$ test and analysis of coincidences between the signal levels in years 1 and 2 of observations that offers a significant improvement in the product of strain sensitivity with compute cycles per data sample compared to previously published searches. Since our search yields no surviving candidates, we present results taking the form of frequency dependent, 95$%$ confidence upper limits on the strain amplitude $h_0$. The most stringent upper limit from year 1 is $1.0\times 10^{-24}$ in the $\mathrm{158.00-158.25 Hz}$ band. In year 2, the most stringent upper limit is $\mathrm{8.9\times10^{-25}}$ in the $\mathrm{146.50-146.75 Hz}$ band. This improved detection pipeline, which is computationally efficient by at least two orders of magnitude better than our flagship Einstein$@$Home search, will be important for "quick-look" searches in the Advanced LIGO and Virgo detector era.
TL;DR: In this paper, the central heating radius of curvature correction (CHROC) was used to adjust the radii of curvatures of the arm cavity end mirrors of the Virgo interferometer.
Abstract: An asymmetry in radii of curvature of the mirrors in the arms of an interferometric gravitational-wave detector can degrade the performance of such a detector. In addition, the non-perfect mirror surface figures can excite higher order modes if the radii of curvature are close to higher order mode degeneracy. In this paper, we present a novel technique for changing the radii of curvature of arm cavity end mirrors by Central Heating Radius of Curvature Correction. This system was installed in the Virgo experiment in Cascina and proved to be an efficient, non-invasive solution with a large dynamic range. We present how the interferometer was tuned using such a system in order to obtain the best duty-cycles and sensitivity achieved with Virgo to date.
01 Jan 2013
TL;DR: Advanced Virgo is the successor of the initial Virgo gravitational wave detector as discussed by the authors, which uses the infrastructure of its predecessor but aims to be 10 times more sensitive than the original Virgo detector.
Abstract: Advanced Virgo is the successor of the initial Virgo gravitational wave detector. This new interferometer will use the infrastructure of its predecessor but aims to be 10 times more sensitive. This presentation will give an overview of the Advanced Virgo design and the technical choices behind it. The different subsystem will be detailed as well as the challenges that can be expected. Finally the up-to-date installation progress and expected schedule will be given.
TL;DR: In this article, the authors presented millimetre-scale silicon resonators designed to exhibit a torsional vibration mode with a frequency in the 105-106 Hz range, for observation of 3-mode optoacoustic interactions in a compact table-top system.
Abstract: Milligram-scale resonators have been shown to be suitable for the creation of 3-mode optoacoustic parametric amplifiers, based on a phenomena first predicted for advanced gravitational-wave detectors. To achieve practical optoacoustic parametric devices, high quality factor resonators are required. We present millimetre-scale silicon resonators designed to exhibit a torsional vibration mode with a frequency in the 105–106 Hz range, for observation of 3-mode optoacoustic interactions in a compact table-top system. Our design incorporates an isolation stage and minimizes the acoustic loss from optical coating. We observe a quality factor of 7.5 × 105 for a mode frequency of 401.5 kHz, at room temperature and pressure of 10–3 Pa. We confirmed the mode shape by mapping the amplitude response across the resonator and comparing to finite element modelling. This study contributes to the development of 3-mode optoacoustic parametric amplifiers for use in novel high-sensitivity signal transducers and quantum measurement experiments.
16 Jun 2013
TL;DR: The LSTM is a new kind of telescope with ambitious scientific objectives as mentioned in this paper, which includes large bandpass filters with high optical requirements: in-band transmission higher than 95%, out-of-band transmissions less than 0.01% and steep edges.
Abstract: LSST is a new kind of telescope with ambitious scientific objectives. Its optical design includes large bandpass filters with high optical requirements: in-band transmission higher than 95%, out-of-band transmission less than 0.01% and steep edges.
TL;DR: In this article, a non-uniform thin film on top of the substrate in order to flatten its surface was applied to an initial Virgo substrate to achieve sub-nanometric flatness.
Abstract: The Advanced Virgo gravitational wave detector aims at a sensitivity ten times better than the initial LIGO and Virgo detectors. This implies very stringent requirement on the optical losses in the interferometer arm cavities. In this paper we focus on the mirrors which form the interferometer arm cavities and that require a surface figure error to be well below one nanometre on a diameter of 150 mm. This 'sub-nanometric flatness' is not achievable by classical polishing on such a large diameter. Therefore we present the corrective coating technique which has been developed to reach this requirement. Its principle is to add a non-uniform thin film on top of the substrate in order to flatten its surface. In this paper we will introduce the Advanced Virgo requirements and present the basic principle of the corrective coating technique. Then we show the results obtained experimentally on an initial Virgo substrate. Finally we provide an evaluation of the round-trip losses in the Fabry-Perot arm cavities once the corrected surface is used.
Posted Content•
TL;DR: In this article, a millimetre-scale silicon resonator was designed to exhibit a torsional vibration mode with a frequency in the 10^5 - 10^6 Hz range, for observation of 3-mode optoacoustic interactions in a compact table-top system.
Abstract: Milligram-scale resonators have been shown to be suitable for the creation of 3-mode optoacoustic parametric amplifiers, based on a phenomena first predicted for advanced gravitational-wave detectors. To achieve practical optoacoustic parametric amplification, high quality factor resonators are required. We present millimetre-scale silicon resonators designed to exhibit a torsional vibration mode with a frequency in the 10^5 - 10^6 Hz range, for observation of 3-mode optoacoustic interactions in a compact table-top system. Our design incorporates an isolation stage and minimizes the acoustic loss from optical coating. We observe a quality factor of 7.5 x 10^5 for a mode frequency of 401.5 kHz, at room temperature and pressure of 10^-3 Pa. We confirmed the mode shape by mapping the amplitude response across the resonator and comparing to finite element modelling. This study contributes towards the development of 3-mode optoacoustic parametric amplifiers for use in novel high-sensitivity signal transducers and quantum measurement experiments.
24 Jun 2013
TL;DR: In this paper, the authors present a structural relaxation analysis based on the direct thermal noise measurements on micro-cantilevers and compare it with the results obtained from the mechanical loss measurements, which give a loss angle of annealed tantala and as-deposited silica coatings of (3.9 ± 0.4)·10-4 and (5.8 ± 1.0)· 10-4 respectively, from 10 Hz to 20 kHz.
Abstract: In recent years an increasing number of devices and experiments are shown to be limited by mechanical thermal noise. In particular sub-Hertz laser frequency stabilization and gravitational wave detectors, that are able to measure fluctuations of 10-18 m/√(Hz) or less, are being limited by thermal noise in the dielectric coatings deposited on mirrors. We present a novel technique of structural relaxation analysis based on the direct thermal noise measurements on micro-cantilevers and we compare it with the results obtained from the mechanical loss measurements. The dielectric coatings are deposited by ion beam sputtering. The results presented here give a loss angle of annealed tantala and as-deposited silica coatings of (3.9 ± 0.4)·10-4 and (5.8 ± 1.0)·10-4 respectively, from 10 Hz to 20 kHz.