Recursos de colección

Caltech Authors (157.532 recursos)

Repository of works by Caltech published authors.

Group = LIGO

Mostrando recursos 1 - 20 de 172

  1. GW170814: A three-detector observation of gravitational waves from a binary black hole coalescence

    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.; Blair, C. D.; Bork, R.; Brooks, A. F.; Brunett, S.; Cahillane, C.; Callister, T. A.; Cepeda, C. B.; Coughlin, M. W.; Couvares, P.; Coyne, D. C.; Ehrens, P.; Eichholz, J.; Etzel, T.; Feicht, J.; Fries, E. M.; Gossan, S. E.; Gushwa, K. E.; Gustafson, E. K.; Heptonstall, A. W.; Isi, M.; Kamai, B.; Kanner, J. B.; Kondrashov, V.; Korth, W. Z.; Kozak, D. B.; Lazzarini, A.; Markowitz, A.; Maros, E.; Massinger, T. J.; Matichard, F.; McIntyre, G.; McIver, J.; Meshkov, S.; Nevin, L.; Pedraza, M.; Perreca, A.; Quintero, E. A.; Reitze, D. H.; Robertson, N. A.; Rollins, J. G.; Sachdev, S.; Sanchez, E. J.; Sanchez, L. E.; Schmidt, P.; 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.; Whitcomb, S. E.; Williams, R. D.; Willis, J. L.; Wipf, C. C.; Xiao, S.; Yamamoto, H.; Zhang, L. Y.; Zucker, M. E.; Zweizig, J.; Barkett, K.; Blackman, J.; Chen, Y.; Ma, Y.; Pang, B.; Scheel, M.; Varma, V.
    On August 14, 2017 at 10:30:43 UTC, the Advanced Virgo detector and the two Advanced LIGO detectors coherently observed a transient gravitational-wave signal produced by the coalescence of two stellar mass black holes, with a false-alarm-rate of ≾ 1 in 27000 years. The signal was observed with a three-detector network matched-filter signal-to-noise ratio of 18. The inferred masses of the initial black holes are 30.5^(+5.7)_(3.0)M⊙ and 25.3^(+2.8)_(4.2)M⊙ (at the 90% credible level). The luminosity distance of the source is 540^(+130)_(210) Mpc, corresponding to a redshift of z =0.11^(+0.03)_(0.04). A network of three detectors improves the sky localization of the source,...

  2. GW170814: A three-detector observation of gravitational waves from a binary black hole coalescence

    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.; Blair, C. D.; Bork, R.; Brooks, A. F.; Brunett, S.; Cahillane, C.; Callister, T. A.; Cepeda, C. B.; Coughlin, M. W.; Couvares, P.; Coyne, D. C.; Ehrens, P.; Eichholz, J.; Etzel, T.; Feicht, J.; Fries, E. M.; Gossan, S. E.; Gushwa, K. E.; Gustafson, E. K.; Heptonstall, A. W.; Isi, M.; Kamai, B.; Kanner, J. B.; Kondrashov, V.; Korth, W. Z.; Kozak, D. B.; Lazzarini, A.; Markowitz, A.; Maros, E.; Massinger, T. J.; Matichard, F.; McIntyre, G.; McIver, J.; Meshkov, S.; Nevin, L.; Pedraza, M.; Perreca, A.; Quintero, E. A.; Reitze, D. H.; Robertson, N. A.; Rollins, J. G.; Sachdev, S.; Sanchez, E. J.; Sanchez, L. E.; Schmidt, P.; 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.; Whitcomb, S. E.; Williams, R. D.; Willis, J. L.; Wipf, C. C.; Xiao, S.; Yamamoto, H.; Zhang, L. Y.; Zucker, M. E.; Zweizig, J.; Barkett, K.; Blackman, J.; Chen, Y.; Ma, Y.; Pang, B.; Scheel, M.; Varma, V.
    On August 14, 2017 at 10:30:43 UTC, the Advanced Virgo detector and the two Advanced LIGO detectors coherently observed a transient gravitational-wave signal produced by the coalescence of two stellar mass black holes, with a false-alarm-rate of ≾ 1 in 27000 years. The signal was observed with a three-detector network matched-filter signal-to-noise ratio of 18. The inferred masses of the initial black holes are 30.5^(+5.7)_(-3.0)M⊙ and 25.3^(+2.8)_(-4.2)M⊙ (at the 90% credible level). The luminosity distance of the source is 540^(+130)_(-210) Mpc, corresponding to a redshift of z =0.11^(+0.03)_(-0.04). A network of three detectors improves the sky localization of the source,...

  3. Upper Limits on Gravitational Waves from Scorpius X-1 from a Model-based Cross-correlation Search in Advanced LIGO Data

    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.; Blackburn, J. K.; Bork, R.; Brooks, A. F.; Brunett, S.; Cahillane, C.; Callister, T. A.; Cepeda, C. B.; Couvares, P.; Coyne, D. C.; Drever, R. W. P.; Ehrens, P.; Eichholz, J.; Etzel, T.; Feichter, J.; 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.; 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.; Pang, B.; Thorne, K. S.; Vallisneri, M.; Varma, V.
    We present the results of a semicoherent search for continuous gravitational waves from the low-mass X-ray binary Scorpius X-1, using data from the first Advanced LIGO observing run. The search method uses details of the modeled, parametrized continuous signal to combine coherently data separated by less than a specified coherence time, which can be adjusted to trade off sensitivity against computational cost. A search was conducted over the frequency range 25–2000 Hz, spanning the current observationally constrained range of binary orbital parameters. No significant detection candidates were found, and frequency-dependent upper limits were set using a combination of sensitivity estimates...

  4. The first direct detection of gravitational waves opens a vast new frontier in astronomy

    Raab, F. J.; Reitze, D. H.
    The first direct detection of gravitational waves (GWs), announced on 11 February 2016, has opened a vast new frontier in astronomy. Albert Einstein predicted the existence of these waves about a century ago as a consequence of his general theory of relativity. Radio astronomy observations of the binary pulsar system PSR 1913 + 16 over a 20 year period beginning in 1975 provided strong observational evidence that gravitational waves carried energy away from the orbits of neutron stars at precisely the level predicted by general relativity (GR). This relentless conversion of orbital energy into gravitational wave energy causes binary orbits to decay until the objects eventually collide and...

  5. Reduction of optimum light power with Heisenberg-limited photon-counting noise in interferometric gravitational-wave detectors

    Brif, Constantin
    We study how the behavior of quantum noise, presenting the fundamental limit on the sensitivity of interferometric gravitational-wave detectors, depends on properties of input states of light. We analyze the situation with specially prepared nonclassical input states which reduce the photon-counting noise to the Heisenberg limit. This results in a great reduction of the optimum light power needed to achieve the standard quantum limit, compared to the usual configuration.

  6. Bulk and shear mechanical loss of titania–doped tantala

    Abernathy, Matthew; Harry, Gregory; Newport, Jonathan; Fair, Hannah; Kinley-Hanlon, Maya; Hickey, Samuel; Jiffar, Isaac; Gretarsson, Andri; Penn, Steve; Bassiri, Riccardo; Gustafson, Eric; Martin, Iain; Rowan, Sheila; Hough, Jim
    We report on the mechanical loss from bulk and shear stresses in thin film, ion beam deposited, titania–doped tantala. The numerical values of these mechanical losses are necessary to fully calculate the Brownian thermal noise in precision optical cavities, including interferometric gravitational wave detectors like LIGO. We found the values from measuring the normal mode mechanical quality factors, Q's, in the frequency range of about 2000-10,000 Hz, of silica disks coated with titania–doped tantala coupled with calculating the elastic energy in shear and bulk stresses in the coating using a finite element model. We fit the results to both a...

  7. Probing dynamical gravity with the polarization of continuous gravitational waves

    Isi, Maximiliano; Pitkin, Matthew; Weinstein, Alan J.
    The direct detection of gravitational waves provides the opportunity to measure fundamental aspects of gravity which have never been directly probed before, including the polarization of gravitational waves. In the context of searches for continuous waves from known pulsars, we present novel methods to detect signals of any polarization content, measure the modes present and place upper limits on the amplitude of nontensorial components. This will allow us to obtain new model-independent, dynamical constraints on deviations from general relativity. We test this framework on multiple potential sources using simulated data from three advanced-era detectors at design sensitivity. We find that...

  8. Guided lock of a suspended optical cavity enhanced by a higher-order extrapolation

    Izumi, Kiwamu; Arai, Koji; Tatsumi, Daisuke; Takahashi, Ryutaro; Miyakawa, Osamu; Fujimoto, Masa-Katsu
    Lock acquisition of a suspended optical cavity can be a highly stochastic process and is therefore nontrivial. Guided lock is a method to make lock acquisition less stochastic by decelerating the motion of the cavity length based on an extrapolation of the motion from an instantaneous velocity measurement. We propose an improved scheme that is less susceptible to seismic disturbances by incorporating the acceleration as a higher-order correction in the extrapolation. We implemented the new scheme in a 300-m suspended Fabry–Perot cavity and improved the success rate of lock acquisition by a factor of 30.

  9. Data Access for LIGO on the OSG

    Weitzel, Derek; Bockelman, Brian; Brown, Duncan A.; Couvares, Peter; Würthwein, Frank; Hernandez, Edgar Fajardo
    During 2015 and 2016, the Laser Interferometer Gravitational-Wave Observatory (LIGO) conducted a three-month observing campaign. These observations delivered the first direct detection of gravitational waves from binary black hole mergers. To search for these signals, the LIGO Scientific Collaboration uses the PyCBC search pipeline. To deliver science results in a timely manner, LIGO collaborated with the Open Science Grid (OSG) to distribute the required computation across a series of dedicated, opportunistic, and allocated resources. To deliver the petabytes necessary for such a large-scale computation, our team deployed a distributed data access infrastructure based on the XRootD server suite and the...

  10. Search for high-energy neutrinos from gravitational wave event GW151226 and candidate LVT151012 with ANTARES and IceCube

    Albert, A.; 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. A.; 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.
    The Advanced LIGO observatories detected gravitational waves from two binary black hole mergers during their first observation run (O1). We present a high-energy neutrino follow-up search for the second gravitational wave event, GW151226, as well as for gravitational wave candidate LVT151012. We find two and four neutrino candidates detected by IceCube, and one and zero detected by Antares, within ± 500 s around the respective gravitational wave signals, consistent with the expected background rate. None of these neutrino candidates are found to be directionally coincident with GW151226 or LVT151012. We use nondetection to constrain isotropic-equivalent high-energy neutrino emission from GW151226,...

  11. Search for high-energy neutrinos from gravitational wave event GW151226 and candidate LVT151012 with ANTARES and IceCube

    Albert, A.; 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. A.; 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.
    The Advanced LIGO observatories detected gravitational waves from two binary black hole mergers during their first observation run (O1). We present a high-energy neutrino follow-up search for the second gravitational wave event, GW151226, as well as for gravitational wave candidate LVT151012. We find two and four neutrino candidates detected by IceCube, and one and zero detected by Antares, within ± 500 s around the respective gravitational wave signals, consistent with the expected background rate. None of these neutrino candidates are found to be directionally coincident with GW151226 or LVT151012. We use nondetection to constrain isotropic-equivalent high-energy neutrino emission from GW151226,...

  12. Search for intermediate mass black hole binaries in the first observing run of Advanced LIGO

    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.; Blackburn, J. K.; Bork, R.; Brooks, A. F.; Brunett, S.; Cahillane, C.; Callister, T. A.; Cepeda, C. B.; Couvares, P.; Coyne, D. C.; Drever, R. W. P.; Ehrens, P.; Eichholz, J.; Etzel, T.; Feicht, J.; 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.; Marx, J. N.; Massinger, T. J.; 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.; Pang, B.; Thorne, K. S.; Varma, V.
    During their first observational run, the two Advanced LIGO detectors attained an unprecedented sensitivity, resulting in the first direct detections of gravitational-wave signals produced by stellar-mass binary black hole systems. This paper reports on an all-sky search for gravitational waves (GWs) from merging intermediate mass black hole binaries (IMBHBs). The combined results from two independent search techniques were used in this study: the first employs a matched-filter algorithm that uses a bank of filters covering the GW signal parameter space, while the second is a generic search for GW transients (bursts). No GWs from IMBHBs were detected; therefore, we constrain...

  13. Crackling noise in advanced gravitational wave detectors: A model of the steel cantilevers used in the test mass suspensions

    Vajente, G.
    The response of elastic materials to external changing conditions can proceed through small and discrete releases of stress, rather than a continuous and smooth deformation as described by the classical elasticity theory. In a macroscopic elastic body, the sum of all those small crackling events can create a detectable displacement noise (crackling noise). In this paper we consider the case of the steel cantilevers used in the seismic isolation systems of ground based gravitational wave detectors, to provide the vertical isolation needed to reach the detector target sensitivity. Those instruments are reaching unprecedented displacement sensitivity, at a level that might...

  14. Observing gravitational waves with a single detector

    Callister, T. A.; Kanner, J. B.; Massinger, T. J.; Dhurandhar, S.; Weinstein, A. J.
    A major challenge of any search for gravitational waves is to distinguish true astrophysical signals from those of terrestrial origin. Gravitational-wave experiments therefore make use of multiple detectors, considering only those signals which appear in coincidence in two or more instruments. It is unclear, however, how to interpret loud gravitational-wave candidates observed when only one detector is operational. In this paper, we demonstrate that the observed rate of binary black hole mergers can be leveraged in order to make confident detections of gravitational-wave signals with one detector alone. We quantify detection confidences in terms of the probability P(S) that a...

  15. A high throughput instrument to measure mechanical losses in thin film coatings

    Vajente, G.; Ananyeva, A.; Billingsley, G.; Gustafson, E.; Heptonstall, A.; Sanchez, E.; Torrie, C.
    Brownian thermal noise generated by mechanical losses in thin film coatings limits the sensitivity of gravitational wave detectors, as well as several high precision metrology experiments. Improving the sensitivity of the next generation of gravitational wave detectors will require optical coatings with significantly reduced mechanical losses. In this paper, we describe a system that we developed to measure the mechanical loss angle of thin film coatings deposited on fused silica substrates. The novelty of this system resides in the capability of parallel measurement of up to four samples and the ability to simultaneously probe all the resonant modes of each...

  16. Search for gravitational waves from Scorpius X-1 in the first Advanced LIGO observing run with a hidden Markov model

    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.; Blackburn, J. K.; Bork, R.; Brooks, A. F.; Brunett, S.; Cahillane, C.; Callister, T. A.; Cepeda, C. B.; Couvares, P.; Coyne, D. C.; Drever, R. W. P.; Ehrens, P.; Eichholz, J.; Etzel, T.; Feicht, J.; 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.; Marx, J. N.; Massinger, T. J.; McIntyre, G.; McIver, J.; Meshkov, S.; Pedraza, M.; Perreca, A.; Quintero, E. A.; Reitze, D. H.; 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.; Pang, B.; Thorne, K. S.; Varma, V.
    Results are presented from a semicoherent search for continuous gravitational waves from the brightest low-mass X-ray binary, Scorpius X-1, using data collected during the first Advanced LIGO observing run. The search combines a frequency domain matched filter (Bessel-weighted F-statistic) with a hidden Markov model to track wandering of the neutron star spin frequency. No evidence of gravitational waves is found in the frequency range 60–650 Hz. Frequentist 95% confidence strain upper limits, h^(95%)_0 = 4.0 × 10^(−25), 8.3 × 10^(−25), and 3.0 × 10^(−25) for electromagnetically restricted source orientation, unknown polarization, and circular polarization, respectively, are reported at 106 Hz....

  17. Search for gravitational waves from Scorpius X-1 in the first Advanced LIGO observing run with a hidden Markov model

    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.; Blackburn, J. K.; Bork, R.; Brooks, A. F.; Brunett, S.; Cahillane, C.; Callister, T. A.; Cepeda, C. B.; Couvares, P.; Coyne, D. C.; Drever, R. W. P.; Ehrens, P.; Eichholz, J.; Etzel, T.; Feicht, J.; 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.; Marx, J. N.; Massinger, T. J.; McIntyre, G.; McIver, J.; Meshkov, S.; Pedraza, M.; Perreca, A.; Quintero, E. A.; Reitze, D. H.; 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.; Pang, B.; Thorne, K. S.; Varma, V.
    Results are presented from a semicoherent search for continuous gravitational waves from the brightest low-mass X-ray binary, Scorpius X-1, using data collected during the first Advanced LIGO observing run. The search combines a frequency domain matched filter (Bessel-weighted F-statistic) with a hidden Markov model to track wandering of the neutron star spin frequency. No evidence of gravitational waves is found in the frequency range 60–650 Hz. Frequentist 95% confidence strain upper limits, h^(95%)_0 = 4.0 × 10^(−25), 8.3 × 10^(−25), and 3.0 × 10^(−25) for electromagnetically restricted source orientation, unknown polarization, and circular polarization, respectively, are reported at 106 Hz....

  18. Readout, Sensing, and Control

    Vajente, Gabriele
    Suspending the mirrors is one of the most crucial tasks in gravitational wave interferometer technology. The performance of the suspensions must provide the required attenuation of seismic noise and reduction of thermal noise, two fundamental limits to the sensitivity of any gravitational wave detector. Moreover, the suspension system must be equipped with sensors and actuators which are used to actively control some relevant degrees of freedom, so to be able to keep the interferometer at its working point (i.e., “locked”). In the first part of this chapter we deal with the basic principles behind the super attenuator chains developed in...

  19. Interferometer Configurations

    Vajente, Gabriele
    Gravitational waves induce a differential strain between free-falling test masses. The most sensitive instruments to measure this kind of effect are laser interferometers. This chapter introduces the working principles of the different optical configuration that were and will be used in gravitational wave detectors: Michelson interferometer, Fabry-Perot resonant cavity, power and signal recycling techniques. Advanced detectors will feature high power levels, therefore the important issue of radiation pressure effects is addressed. Finally, a brief introduction to the topic of diffraction limited beams and high order transverse electromagnetic modes is included.

  20. Gravitational waves: search results, data analysis and parameter estimation

    Astone, Pia; Weinstein, Alan; Privitera, Stephen
    The Amaldi 10 Parallel Session C2 on gravitational wave (GW) search results, data analysis and parameter estimation included three lively sessions of lectures by 13 presenters, and 34 posters. The talks and posters covered a huge range of material, including results and analysis techniques for ground-based GW detectors, targeting anticipated signals from different astrophysical sources: compact binary inspiral, merger and ringdown; GW bursts from intermediate mass binary black hole mergers, cosmic string cusps, core-collapse supernovae, and other unmodeled sources; continuous waves from spinning neutron stars; and a stochastic GW background. There was considerable emphasis on Bayesian techniques for estimating the...

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