Beating the Spin-Down Limit on Gravitational Wave Emission from the Crab Pulsar
B. Abbott, Loyola University New Orleans
R. Abbott, Leibniz University Hannover
R. Adhikari, Max Planck Institute for Gravitational Physics (Albert Einstein Institute)
P. Ajith, University of Western Australia
B. Allen, Southern University and A&M College
G. Allen, California Institute of Technology
R. Amin, University of Birmingham
S. B. Anderson, Charles Sturt University
W. G. Anderson, University of Adelaide
M. A. Arain, Inter-University Centre for Astronomy and Astrophysics India
M. Araya, The LIGO Scientific Collaboration
H. Armandula, Cardiff University
P. Armor, Massachusetts Institute of Technology
Y. Aso, University of Florida
S. Aston, University of Strathclyde
P. Aufmuth, LIGO - California Institute of Technology
C. Aulbert, Rutherford Appleton Laboratory
S. Babak, McNeese State University
S. Ballmer, National Science Foundation
H. Bantilan, University of Wisconsin-Milwaukee
B. C. Barish, Washington State University Pullman
C. Barker, University of Minnesota
D. Barker, Stanford University
B. Barr, University of Glasgow
P. Barriga, University of Maryland
M. A. Barton, Lomonosov Moscow State University
M. Bastarrika, University of Salerno
K. Bayer, Carleton College
J. Betzwieser, University of Rochester
P. T. Beyersdorf, University of Massachusetts
Abstract
We present direct upper limits on gravitational wave emission from the Crab pulsar using data from the first 9 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 our results in the context of two possible gravitational wave emission mechanisms.
