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Full-Text Articles in Physical Sciences and Mathematics

Gravitational Wave Burst Source Direction Estimation Using Time And Amplitude Information, J. Markowitz, M. Zanolin, L. Cadonati, E. Katsavounidis Dec 2008

Gravitational Wave Burst Source Direction Estimation Using Time And Amplitude Information, J. Markowitz, M. Zanolin, L. Cadonati, E. Katsavounidis

Publications

In this article we study two problems that arise when using timing and amplitude estimates from a network of interferometers (IFOs) to evaluate the direction of an incident gravitational wave burst (GWB). First, we discuss an angular bias in the least squares timing-based approach that becomes increasingly relevant for moderate to low signal-to-noise ratios. We show how estimates of the arrival time uncertainties in each detector can be used to correct this bias. We also introduce a stand alone parameter estimation algorithm that can improve the arrival time estimation and provide root-sum-squared strain amplitude (h(rss)) values for each site. In …


Gravity Has A Story To Tell: Lisa And The Search For Low Frequency Gravitational Waves, Shane L. Larson Nov 2008

Gravity Has A Story To Tell: Lisa And The Search For Low Frequency Gravitational Waves, Shane L. Larson

Colloquia and Seminars

No abstract provided.


Towards A Fully Nonlinear Cauchy Characteristic Extraction, Maria Babiuc-Hamilton Sep 2008

Towards A Fully Nonlinear Cauchy Characteristic Extraction, Maria Babiuc-Hamilton

Physics Faculty Research

The artificial finite outer boundary present in Cauchy codes introduce two sources of error: The outer boundary condition and waveform extraction at an inner worldtube. The problem of proper boundary condition for a radiating system can be solved only by extension to Ι+ (conformal compactification). Cauchy Characteristic Extraction (CCE) offers a means to avoid these errors.


Vignettes From The World Of Gravitational Wave Astrophysics, Shane L. Larson Sep 2008

Vignettes From The World Of Gravitational Wave Astrophysics, Shane L. Larson

Colloquia and Seminars

No abstract provided.


Songs From The Milky Way: Our Galaxy In Low Frequency Gravitational Waves, Shane L. Larson Sep 2008

Songs From The Milky Way: Our Galaxy In Low Frequency Gravitational Waves, Shane L. Larson

Colloquia and Seminars

No abstract provided.


Whispers From The Cosmos: Seeing The Universe In Gravitational Waves, Shane L. Larson Jul 2008

Whispers From The Cosmos: Seeing The Universe In Gravitational Waves, Shane L. Larson

Colloquia and Seminars

No abstract provided.


Implications For The Origin Of Grb 070201 From Ligo Observations, B. Abbott, R. Abbott, R. Adhikari, J. Agresti, P. Ajith, B. Allen, R. Amin, S. B. Anderson, W. G. Anderson, M. Arain, M. Araya, H. Armandula, M. Ashley, S. Aston, P. Aufmuth, C. Aulbert, S. Babak, S. Ballmer, H. Bantilan, B. C. Barish, C. Barker, D. Barker, B. Barr, P. Barriga, M. A. Barton, K. Bayer, J. Betzwieser, P. T. Beyersdorf, B. Bhawal, I. A. Bilenko, G. Billingsley, Tiffany Z. Summerscales Jul 2008

Implications For The Origin Of Grb 070201 From Ligo Observations, B. Abbott, R. Abbott, R. Adhikari, J. Agresti, P. Ajith, B. Allen, R. Amin, S. B. Anderson, W. G. Anderson, M. Arain, M. Araya, H. Armandula, M. Ashley, S. Aston, P. Aufmuth, C. Aulbert, S. Babak, S. Ballmer, H. Bantilan, B. C. Barish, C. Barker, D. Barker, B. Barr, P. Barriga, M. A. Barton, K. Bayer, J. Betzwieser, P. T. Beyersdorf, B. Bhawal, I. A. Bilenko, G. Billingsley, Tiffany Z. Summerscales

Faculty Publications

We analyzed the available LIGO data coincident with GRB 070201, a short-duration, hard-spectrum γ-ray burst (GRB) whose electromagnetically determined sky position is coincident with the spiral arms of the Andromeda galaxy (M31). Possible progenitors of such short, hard GRBs include mergers of neutron stars or a neutron star and a black hole, or soft γ-ray repeater (SGR) flares. These events can be accompanied by gravitational-wave emission. No plausible gravitational-wave candidates were found within a 180 s long window around the time of GRB 070201. This result implies that a compact binary progenitor of GRB 070201, with masses in the range …


Beating The Spin-Down Limit On Gravitational Wave Emission From The Crab Pulsar, Ligo Scientific Collaboration, Nelson Christensen, Jan 2008

Beating The Spin-Down Limit On Gravitational Wave Emission From The Crab Pulsar, Ligo Scientific Collaboration, Nelson Christensen,

Faculty Work

We present direct upper limits on gravitational wave emission from the Crab pulsar using data from the first nine months of the fifth science run of the Laser Interferometer Gravitational-wave Observatory (LIGO). These limits are based on two searches. In the first we assume that the gravitational wave emission follows the observed radio timing, giving an upper limit on gravitational wave emission that beats indirect limits inferred from the spin-down and braking index of the pulsar and the energetics of the nebula. In the second we allow for a small mismatch between the gravitational and radio signal frequencies and interpret …