Recursos de colección

Caltech Authors (143.226 recursos)

Repository of works by Caltech published authors.

Group = LIGO

Mostrando recursos 1 - 20 de 144

  1. LIGO and the opening of a unique observational window on the universe

    Kalogera, Vassiliki; Lazzarini, Albert
    A unique window on the universe opened on September 14, 2015, with direct detection of gravitational waves by the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) detectors. This event culminated a half-century effort around the globe to develop terrestrial detectors of adequate sensitivity to achieve this goal. It also happened appropriately only a few months before the centennial of Einstein’s final paper introducing the general theory of relativity. This detection provided the surprising discovery of a coalescing pair of “heavy” black holes (more massive than ≃ 25 M_๏) leading to the formation of a spinning ≃ 62 solar mass black hole. One...

  2. Cryogenically cooled ultra low vibration silicon mirrors for gravitational wave observatories

    Shapiro, Brett; Adhikari, Rana X.; Aguiar, Odylio; Bonilla, Edgard; Fan, Danyang; Gan, Litawn; Gomez, Ian; Khandelwal, Sanditi; Lantz, Brian; MacDonald, Tim; Madden-Fong, Dakota
    Interferometric gravitational wave observatories recently launched a new field of gravitational wave astronomy with the first detections of gravitational waves in 2015. The number and quality of these detections is limited in part by thermally induced vibrations in the mirrors, which show up as noise in these interferometers. One way to reduce this thermally induced noise is to use low temperature mirrors made of high purity single-crystalline silicon. However, these low temperatures must be achieved without increasing the mechanical vibration of the mirror surface or the vibration of any surface within close proximity to the mirrors. The vibration of either...

  3. All-sky search for short gravitational-wave bursts in the first Advanced LIGO run

    Abbott, B. P.; Abbott, R.; Adhikari, R. X.; Ananyeva, A.; Anderson, S. B.; Appert, S.; Arai, K.; Araya, M. C.; Barayoga, J. C.; Barish, B. C.; Berger, B. K.; Billingsley, G.; Biscans, S; Blackburn, J. K.; Bork, R.; Brooks, A. F.; Brunett, S.; Cahillane, C.; Callister, T.; Cepeda, C. B.; Couvares, P.; Coyne, D. C.; Drever, R. W. P.; Ehrens, P.; Eichholz, J.; Etzel, T.; Fries, E. M.; Gossan, S. E.; Gushwa, K. E.; Gustafson, E. K.; Hall, E. D.; Heptonstall, A. W.; Isi, M.; Kanner, J. B.; Kondrashov, V.; Korth, W. Z.; Kozak, D. B.; Lazzarini, A.; Maros, E.; Massinger, T. J.; Matichard, F.; McIntyre, G.; McIver, J.; Meshkov, S.; Pedraza, M.; Perreca, A.; Quintero, E. A.; Reitze, D. H.; Robertson, N. A.; Rollins, J. G.; Sachdev, S.; Sanchez, E. J.; Schmidt, P.; Singer, A.; Smith, R. J. E.; Taylor, R.; Torrie, C. I.; Tso, R.; Urban, A. L.; Vajente, G.; Vass, S.; Venugopalan, G.; Wade, A. R.; Wallace, L.; Weinstein, A. J.; Williams, R. D.; Wipf, C. C.; Yamamoto, H.; Zhang, L.; Zucker, M. E.; Zweizig, J.; Blackman, J.; Chen, Y.; Ma, Y.; Varma, V.
    We present the results from an all-sky search for short-duration gravitational waves in the data of the first run of the Advanced LIGO detectors between September 2015 and January 2016. The search algorithms use minimal assumptions on the signal morphology, so they are sensitive to a wide range of sources emitting gravitational waves. The analyses target transient signals with duration ranging from milliseconds to seconds over the frequency band of 32 to 4096 Hz. The first observed gravitational-wave event, GW150914, has been detected with high confidence in this search; the other known gravitational-wave event, GW151226, falls below the search’s sensitivity....

  4. Development of a high-resolution optical inertial sensor for sub-Hz seismic isolation

    Watchi, Jennifer; Ding, Binlei; Matichard, Fabrice; Collette, Christophe
    Precision engineering tasks require active isolation systems that are efficient especially at low frequencies. The limitations of such control systems include the resolution of the sensor used and the magnetic coupling between the sensor and the actuator. In order to bypass these limitations, inertial sensors using Michelson interferometer are being developed. A first prototype has been built and tested. It has been shown that it has a sub-nanometer resolution over a large frequency range, extending from 0.1 Hz to 100 Hz. To further improve the resolution, a new optical design will be presented in this paper. The elements of the setup are chosen...

  5. The emergence of gravitational wave science: 100 years of development of mathematical theory, detectors, numerical algorithms, and data analysis tools

    Holst, Michael; Sarbach, Olivier; Tiglio, Manuel; Vallisneri, Michele
    On September 14, 2015, the newly upgraded Laser Interferometer Gravitational-wave Observatory (LIGO) recorded a loud gravitational-wave (GW) signal, emitted a billion light-years away by a coalescing binary of two stellar-mass black holes. The detection was announced in February 2016, in time for the hundredth anniversary of Einstein's prediction of GWs within the theory of general relativity (GR). The signal represents the first direct detection of GWs, the first observation of a black-hole binary, and the first test of GR in its strong-field, high-velocity, nonlinear regime. In the remainder of its first observing run, LIGO observed two more signals from black-hole...

  6. Improved effective-one-body model of spinning, nonprecessing binary black holes for the era of gravitational-wave astrophysics with advanced detectors

    Bohé, Alejandro; Shao, Lijing; Taracchini, Andrea; Buonanno, Alessandra; Babak, Stanislav; Harry, Ian W.; Hinder, Ian; Ossokine, Serguei; Pürrer, Michael; Raymond, Vivien; Chu, Tony; Fong, Heather; Kumar, Prayush; Pfeiffer, Harald P.; Boyle, Michael; Hemberger, Daniel A.; Kidder, Lawrence E.; Lovelace, Geoffrey; Scheel, Mark A.; Szilágyi, Béla
    We improve the accuracy of the effective-one-body (EOB) waveforms that were employed during the first observing run of Advanced LIGO for binaries of spinning, nonprecessing black holes by calibrating them to a set of 141 numerical-relativity (NR) waveforms. The NR simulations expand the domain of calibration toward larger mass ratios and spins, as compared to the previous EOBNR model. Merger-ringdown waveforms computed in black-hole perturbation theory for Kerr spins close to extremal provide additional inputs to the calibration. For the inspiral-plunge phase, we use a Markov-chain Monte Carlo algorithm to efficiently explore the calibration space. For the merger-ringdown phase, we...

  7. Overview and Status of Advanced Interferometers for Gravitational Wave Detection

    Grote, H.
    The world-wide network of km-scale laser interferometers is aiming at the detection of gravitational waves of astrophysical origin. The second generation of these instruments, called advanced detectors has been, or is in the process of being completed, and a first observational run with the Advanced LIGO interferometers has been performed late in 2015. The basic functionality of advanced detectors is discussed, along with specific features and status updates of the individual projects.

  8. Analysis framework for the prompt discovery of compact binary mergers in gravitational-wave data

    Messick, Cody; Blackburn, Kent; Sachdev, Surabhi; Weinstein, Alan
    We describe a stream-based analysis pipeline to detect gravitational waves from the merger of binary neutron stars, binary black holes, and neutron-star–black-hole binaries within ∼1 min of the arrival of the merger signal at Earth. Such low-latency detection is crucial for the prompt response by electromagnetic facilities in order to observe any fading electromagnetic counterparts that might be produced by mergers involving at least one neutron star. Even for systems expected not to produce counterparts, low-latency analysis of the data is useful for deciding when not to point telescopes, and as feedback to observatory operations. Analysts using this pipeline were...

  9. Cosmological inference using only gravitational wave observations of binary neutron stars

    Del Pozzo, Walter; Li, Tjonnie G. F.; Messenger, Chris
    Gravitational waves emitted during the coalescence of binary neutron star systems are self-calibrating signals. As such, they can provide a direct measurement of the luminosity distance to a source without the need for a cross-calibrated cosmic distance-scale ladder. In general, however, the corresponding redshift measurement needs to be obtained via electromagnetic observations since it is totally degenerate with the total mass of the system. Nevertheless, Fisher matrix studies have shown that, if information about the equation of state of the neutron stars is available, it is possible to extract redshift information from the gravitational wave signal alone. Therefore, measuring the...

  10. An architecture for efficient multimodal gravitational wave parameter estimation with linear surrogate models

    O'Shaughnessy, Richard; Blackman, Jonathan; Field, Scott E.
    The recent direct detection of gravitational waves has further emphasized the need for fast, low-cost, and accurate methods to infer the parameters of gravitational wave sources. The performance of these calculations is limited by the cost of evaluating the likelihood function, due to expense in data handling and waveform generation. Building on recently developed surrogate models and a novel parameter estimation pipeline, we show how to quickly generate the likelihood function as a simple, analytic closed-form expression. Using a simple variant of a production-scale parameter estimation code, we demonstrate our method using surrogate models of effective-one-body and numerical relativity waveforms. Our study is the first time these models have...

  11. An architecture for efficient multimodal gravitational wave parameter estimation with linear surrogate models

    O'Shaughnessy, Richard; Blackman, Jonathan; Field, Scott E.
    The recent direct detection of gravitational waves has further emphasized the need for fast, low-cost, and accurate methods to infer the parameters of gravitational wave sources. The performance of these calculations is limited by the cost of evaluating the likelihood function, due to expense in data handling and waveform generation. Building on recently developed surrogate models and a novel parameter estimation pipeline, we show how to quickly generate the likelihood function as a simple, analytic closed-form expression. Using a simple variant of a production-scale parameter estimation code, we demonstrate our method using surrogate models of effective-one-body and numerical relativity waveforms. Our study is the first time these models have...

  12. Complete waveform model for compact binaries on eccentric orbits

    Huerta, E. A.; Kumar, Prayush; Agarwal, Bhanu; George, Daniel; Schive, Hsi-Yu; Pfeiffer, Harald P.; Haas, Roland; Ren, Wei; Chu, Tony; Boyle, Michael; Hemberger, Daniel A.; Kidder, Lawrence E.; Scheel, Mark A.; Szilágyi, Béla
    We present a time domain waveform model that describes the inspiral, merger and ringdown of compact binary systems whose components are nonspinning, and which evolve on orbits with low to moderate eccentricity. The inspiral evolution is described using third-order post-Newtonian equations both for the equations of motion of the binary, and its far-zone radiation field. This latter component also includes instantaneous, tails and tails-of-tails contributions, and a contribution due to nonlinear memory. This framework reduces to the post-Newtonian approximant TaylorT4 at third post-Newtonian order in the zero-eccentricity limit. To improve phase accuracy, we also incorporate higher-order post-Newtonian corrections for the...

  13. Exploring the sensitivity of next generation gravitational wave detectors

    Abbott, B. P.; Abbott, R.; Adhikari, R. X.; Anderson, S. B.; Arai, K.; Araya, M. C.; Barayoga, J. C.; Barish, B. C.; Berger, B. K.; Billingsley, G.; Blackburn, J. K.; Bork, R.; Brooks, A. F.; Brunett, S.; Cahillane, C.; Callister, T.; Cepeda, C. B.; Chen, Y.; Couvares, P.; Coyne, D. C.; Dergachev, V.; Drever, R. W. P.; Ehrens, P.; Eichholz, J.; Engels, W.; Etzel, T.; Gossan, S. E.; Gushwa, K. E.; Gustafson, E. K.; Hall, E. D.; Heptonstall, A. W.; Isi, M.; Kanner, J. B.; Kells, W.; Kondrashov, V.; Korth, W. Z.; Kozak, D. B.; Lazzarini, A.; Lewis, J. B.; Maros, E.; McIntyre, G.; McIver, J.; Meshkov, S.; Pedraza, M.; Perreca, A.; Price , L. R.; Quintero, E. A.; Reitze, D. H.; Robertson, N. A.; Rollins, J. G.; Sachdev, S.; Sanchez, E. J.; Schmidt, P.; Singer, A.; Smith, N. D.; Smith, R. J. E.; Taylor, R.; Thirugnanasambandam, M. P.; Torrie, C. I.; Vajente, G.; Vass, S.; Wallace, L.; Weinstein, A. J.; Williams, R. D.; Wipf, C. C.; Yamamoto, H.; Zhang, L.; Zucker, M. E.; Zweizig, J.
    The second-generation of gravitational-wave detectors are just starting operation, and have already yielding their first detections. Research is now concentrated on how to maximize the scientific potential of gravitational-wave astronomy. To support this effort, we present here design targets for a new generation of detectors, which will be capable of observing compact binary sources with high signal-to-noise ratio throughout the Universe.

  14. Preparing for Advanced LIGO: A Star–Galaxy Separation Catalog for the Palomar Transient Factory

    Miller, A. A.; Kulkarni, M. K.; Cao, Y.; Laher, R. R.; Masci, F. J.; Surace, J. A.
    The search for fast optical transients, such as the expected electromagnetic counterparts to binary neutron star mergers, is riddled with false positives (FPs) ranging from asteroids to stellar flares. While moving objects are readily rejected via image pairs separated by ~1 hr, stellar flares represent a challenging foreground, significantly outnumbering rapidly evolving explosions. Identifying stellar sources close to and fainter than the transient detection limit can eliminate these FPs. Here, we present a method to reliably identify stars in deep co-adds of Palomar Transient Factory (PTF) imaging. Our machine-learning methodology utilizes the random forest (RF) algorithm, which is trained using...

  15. Search for continuous gravitational waves from neutron stars in globular cluster NGC 6544

    Abbott, B. P.; Abbott, R.; Adhikari, R. X.; Anderson, S. B.; Arai, K.; Araya, M. C.; Barayoga, J. C.; Barish, B. C.; Berger, B. K.; Billingsley, G.; Blackburn, J. K.; Bork, R.; Brooks, A. F.; Brunett, S.; Cahillane, C.; Callister, T.; Cepeda, C. B.; Chen, Y.; Couvares, P.; Coyne, D. C.; Dergachev, V.; Drever, R. W. P.; Ehrens, P.; Eichholz, J.; Engels, W.; Etzel, T.; Gossan, S. E.; Gushwa, K. E.; Gustafson, E. K.; Hall, E. D.; Heptonstall, A. W.; Isi, M.; Kanner, J. B.; Kells, W.; Kondrashov, V.; Korth, W. Z.; Kozak, D. B.; Lewis, J. B.; Maros, E.; Marx, J. N.; McIntyre, G.; McIver, J.; Meshkov, S.; Patel, P.; Pedraza, M.; Perreca, A.; Price , L. R.; Quintero, E. A.; Reitze, D. H.; Robertson, N. A.; Rollins, J. G.; Sachdev, S.; Sanchez, E. J.; Schmidt, P.; Singer, A.; Smith, N. D.; Smith, R. J. E.; Taylor, R.; Thirugnanasambandam, M. P.; Torrie, C. I.; Vajente, G.; Vass, S.; Wallace, L.; Weinstein, A. J.; Williams, R. D.; Wipf, C. C.; Yamamoto, H.; Zhang, L.; Zucker, M. E.; Zweizig, J.
    We describe a directed search for continuous gravitational waves in data from the sixth initial LIGO science run. The target was the nearby globular cluster NGC 6544 at a distance of ≈ 2:7 kpc. The search covered a broad band of frequencies along with first and second frequency derivatives for a fixed sky position. The search coherently integrated data from the two LIGO interferometers over a time span of 9.2 days using the matched-filtering Ƒ-statistic. We found no gravitational-wave signals and set 95% confidence upper limits as stringent as 6.0 x 10^(-25) on intrinsic strain and 8.5 x 10^(-6) on...

  16. Improving LIGO calibration accuracy by tracking and compensating for slow temporal variations

    Tuyenbayev, D.; Karki, S.; Betzwieser, J.; Cahillane, C.; Goetz, E.; Izumi, K.; Kandhasamy, S.; Kissel, J. S.; Mendell, G.; Wade, M.; Weinstein, A. J.; Savage, R. L.
    Calibration of the second-generation LIGO interferometric gravitational-wave detectors employs a method that uses injected periodic modulations to track and compensate for slow temporal variations in the differential length response of the instruments. These detectors utilize feedback control loops to maintain resonance conditions by suppressing differential arm length variations. We describe how the sensing and actuation functions of these servo loops are parameterized and how the slow variations in these parameters are quantified using the injected modulations. We report the results of applying this method to the LIGO detectors and show that it significantly reduces systematic errors in their calibrated outputs.

  17. Small optic suspensions for Advanced LIGO input optics and other precision optical experiments

    Ciani, G.; Arain, M. A.; Aston, S. M.; Feldbaum, D.; Fulda, P.; Gleason, J.; Heintze, M.; Martin, R. M.; Mueller, C. L.; Kumar, D. M. Nanda; Pele, A.; Reitze, D. H.; Sainathan, P.; Tanner, D. B.; Williams, L. F.; Mueller, G.
    We report on the design and performance of small optic suspensions developed to suppress seismic motion of out-of-cavity optics in the input optics subsystem of the Advanced Laser Interferometer Gravitational Wave Observatory. These compact single stage suspensions provide isolation in all six degrees of freedom of the optic, local sensing and actuation in three of them, and passive damping for the other three.

  18. Impact of an improved neutrino energy estimate on outflows in neutron star merger simulations

    Foucart, Francois; O’Connor, Evan; Roberts, Luke; Kidder, Lawrence E.; Pfeiffer, Harald P.; Scheel, Mark A.
    Binary neutron star mergers are promising sources of gravitational waves for ground-based detectors such as Advanced LIGO. Neutron-rich material ejected by these mergers may also be the main source of r-process elements in the Universe, while radioactive decays in the ejecta can power bright electromagnetic postmerger signals. Neutrino-matter interactions play a critical role in the evolution of the composition of the ejected material, which significantly impacts the outcome of nucleosynthesis and the properties of the associated electromagnetic signal. In this work, we present a simulation of a binary neutron star merger using an improved method for estimating the average neutrino...

  19. Inferring the core-collapse supernova explosion mechanism with gravitational waves

    Powell, Jade; Gossan, Sarah E.; Logue, Joshua; Heng, Ik Siong
    A detection of a core-collapse supernova (CCSN) gravitational-wave (GW) signal with an Advanced LIGO and Virgo detector network may allow us to measure astrophysical parameters of the dying massive star. GWs are emitted from deep inside the core, and, as such, they are direct probes of the CCSN explosion mechanism. In this study, we show how we can determine the CCSN explosion mechanism from a GW supernova detection using a combination of principal component analysis and Bayesian model selection. We use simulations of GW signals from CCSN exploding via neutrino-driven convection and rapidly rotating core collapse. Previous studies have shown...

  20. The Pegasus portal: web based grid computing

    Singh, Gurmeet; Deelman, Ewa; Metha, Gaurang; Vahi, Karan; Su, Mei-Hui; Berriman, G. Bruce; Good, John; Jacob, Joseph C.; Katz, Daniel S.; Lazzarini, Albert; Blackburn, Kent; Koranda, Scott
    Pegasus is a planning framework for mapping abstract workflows for execution on the Grid. This paper presents the implementation of a web-based portal for submitting workflows to the Grid using Pegasus. The portal also includes components for generating abstract workflows based on a metadata description of the desired data products and application-specific services. We describe our experiences in using this portal for two Grid applications. A major contribution of our work is in introducing several components that can be useful for Grid portals and hence should be included in Grid portal development toolkits.

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