Sengupta, Anand et al.Anand et al.Sengupta2025-08-302025-08-302015-11-0110.1088/0004-637X/813/1/392-s2.0-84946761754https://repository.iitgn.ac.in/handle/IITG2025/21398We 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.truegravitational waves | ISM: supernova remnants | stars: neutronArticlehttps://iopscience.iop.org/article/10.1088/0004-637X/813/1/39/pdf153843571 November 2015633969WOS:000365284100039