We performed a simultaneous observational run with prototypes of Torsion-bar Antenna (TOBA) and searched for a stochastic gravitational waves (GW) background. TOBA is a new type of GW detector which measures differential rotation of two test-mass bars caused by tidal force from GWs. It fundamentally has a good sensitivity at lower frequencies, such as 0.1-1.0 Hz. The prototype has a 20-cm test mass bar which is levitated by the pinning effect of a superconductor. The data was taken from 1:00 am to 10:00 am on March 11th 2011, at Tokyo and Kyoto in Japan. As a result, we did not detect a stochastic GW background with false alarm rate of 5 %, and set an upper limit on a stochastic GW background. Our 95 % confidence upper limit is Ωgwh 20 < 1.2 × 1019 at 0.06 - 0.9 Hz, where Ωgw is the GW energy density per logarithmic frequency interval in units of the critical density and ho is the Hubble constant per 100 km/sec/Mpc. We had established the simultaneous observation and the analysis pipeline with two TOBAs, and set an upper limit at a wider frequency band.
|Journal||Journal of Physics: Conference Series|
|Publication status||Published - 2012|
|Event||9th Edoardo Amaldi Conference on Gravitational Waves, Amaldi 9 and the 2011 Numerical Relativity - Data Analysis Meeting, NRDA 2011 - Cardiff, United Kingdom|
Duration: 2011 Jul 10 → 2011 Jul 15
ASJC Scopus subject areas
- Physics and Astronomy(all)