We describe directed searches for continuous gravitational waves (GWs) in data from the sixth Laser Interferometer Gravitational-wave Observatory (LIGO) science data run. The targets were nine young supernova remnants not associated with pulsars; eight of the remnants are associated with non-pulsing suspected neutron stars. One target's parameters are uncertain enough to warrant two searches, for a total of 10. Each search covered a broad band of frequencies and first and second frequency derivatives for a fixed sky direction. The searches coherently integrated data from the two LIGO interferometers over time spans from 5.3-25.3 days using the matched-filtering -statistic. We found no evidence of GW signals. We set 95% confidence upper limits as strong (low) as 4 × 10-25 on intrinsic strain, 2 × 10-7 on fiducial ellipticity, and 4 × 10-5 on r-mode amplitude. These beat the indirect limits from energy conservation and are within the range of theoretical predictions for neutron-star ellipticities and r-mode amplitudes.
Publication Source (Journal or Book title)
Aasi, J., Abbott, B., Abbott, R., Abbott, T., Abernathy, M., Acernese, F., Ackley, K., Adams, C., Adams, T., Addesso, P., Adhikari, R., Adya, V., Affeldt, C., Agathos, M., Agatsuma, K., Aggarwal, N., Aguiar, O., Ain, A., Ajith, P., Alemic, A., Allen, B., Allocca, A., Amariutei, D., Anderson, S., Anderson, W., Arai, K., Araya, M., Arceneaux, C., Areeda, J., Ast, S., Aston, S., Astone, P., & Aufmuth, P. (2015). SEARCHES for CONTINUOUS GRAVITATIONAL WAVES from NINE YOUNG SUPERNOVA REMNANTS. Astrophysical Journal, 813 (1) https://doi.org/10.1088/0004-637X/813/1/39