Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Test for gravitational waves

  1. Feb 21, 2014 #1

    wolram

    User Avatar
    Gold Member

    Null results so far for the elusive gravitational search, but were they expected to be found at this range?

    arXiv:1402.4974 (cross-list from gr-qc) [pdf, ps, other]
    Implementation of an F-statistic all-sky search for continuous gravitational waves in Virgo VSR1 data
    J. Aasi, B. P. Abbott, R. Abbott, T. Abbott, M. R. Abernathy, T. Accadia, F. Acernese, K. Ackley, C. Adams, T. Adams, P. Addesso, R. X. Adhikari, C. Affeldt, M. Agathos, N. Aggarwal, O. D. Aguiar, A. Ain, P. Ajith, A. Alemic, B. Allen, A. Allocca, D. Amariutei, M. Andersen, R. Anderson, S. B. Anderson, W. G. Anderson, K. Arai, M. C. Araya, C. Arceneaux, J. Areeda, S. M. Aston, P. Astone, P. Aufmuth, C. Aulbert, L. Austin, B. E. Aylott, S. Babak, P. T. Baker, G. Ballardin, S. W. Ballmer, J. C. Barayoga, M. Barbet, B. C. Barish, D. Barker, F. Barone, B. Barr, L. Barsotti, M. Barsuglia, M. A. Barton, I. Bartos, R. Bassiri, A. Basti, J. C. Batch, J. Bauchrowitz, Th. S. Bauer, B. Behnke, M. Bejger, M. G. Beker, C. Belczynski, A. S. Bell, C. Bell, G. Bergmann, D. Bersanetti, A. Bertolini, J. Betzwieser, et al. (785 additional authors not shown)
    Comments: 27 pages, 10 figures, submitted to CQG
    Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE); Instrumentation and Methods for Astrophysics (astro-ph.IM)
    We present an implementation of the $\mathcal{F}$-statistic to carry out the first search in data from the Virgo laser interferometric gravitational wave detector for periodic gravitational waves from a priori unknown, isolated rotating neutron stars. We searched a frequency $f_0$ range from 100 Hz to 1 kHz and the frequency dependent spindown $f_1$ range from $-1.6\,(f_0/100\,{\rm Hz}) \times 10^{-9}\,$ Hz/s to zero. A large part of this frequency - spindown space was unexplored by any of the all-sky searches published so far. Our method consisted of a coherent search over two-day periods using the $\mathcal{F}$-statistic, followed by a search for coincidences among the candidates from the two-day segments. We have introduced a number of novel techniques and algorithms that allow the use of the Fast Fourier Transform (FFT) algorithm in the coherent part of the search resulting in a fifty-fold speed-up in computation of the $\mathcal{F}$-statistic with respect to the algorithm used in the other pipelines. No significant gravitational wave signal was found. The sensitivity of the search was estimated by injecting signals into the data. In the most sensitive parts of the detector band more than 90% of signals would have been detected with dimensionless gravitational-wave amplitude greater than $5 \times 10^{-24}$.
     
    Last edited: Feb 21, 2014
  2. jcsd
  3. Feb 21, 2014 #2

    Chronos

    User Avatar
    Science Advisor
    Gold Member

    It looks like they used data from the original Virgo design, so it is unsurprising they came up empty this run. The sensitivity was not expected to be sufficient to detect more than 0.1 events per year. Advance Virgo, expected to come on line in 2017, will be much more sensitivity and yield much better detection probability. For further information, see http://hal.archives-ouvertes.fr/docs/00/28/06/10/PDF/in2p3-00280610.pdf
     
  4. Feb 26, 2014 #3
    I'll read the paper Chronos suggests in the morning, but I wonder, how do they hold the temperature (energy/momentum) constant enough between the mirrors to get an interference pattern?
     
  5. Feb 27, 2014 #4

    mfb

    User Avatar
    2016 Award

    Staff: Mentor

    With a lot of cooling effort. I think constant is not the issue, just colder than the environment (and with some way to get rid of absorbed beam power).
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Test for gravitational waves
  1. Gravitational Waves (Replies: 20)

  2. Gravitational waves (Replies: 11)

Loading...