It has been recognized that the magnetic fields from the Schumann resonances could affect the search for a stochastic gravitational-wave background by LIGO and Virgo. Presented here are the observations of short duration magnetic field transients that are coincident in the magnetometers at the LIGO and Virgo sites. Data from low-noise magnetometers in Poland and Colorado, USA, are also used and show short duration magnetic transients of global extent. We measure at least 2.3 coincident (between Poland and Colorado) magnetic transient events per day where one of the pulses exceeds 200 pT. Given the recently measured values of the magnetic coupling to differential arm motion for Advanced LIGO, there would be a few events per day that would appear simultaneously at the gravitational-wave detector sites and could move the test masses of order 10-18 m. We confirm that in the advanced detector era short duration transient gravitational-wave searches must account for correlated magnetic field noise in the global detector network.
Bibliographical noteFunding Information:
NC and MR are supported by National Science Foundation (NSF) grant PHY-1505373 to Carleton College. MG acknowledges support from the NSF under Award AGS 1451210 to University of Colorado Denver. MC is supported by the NSF Graduate Research Fellowship Program, under NSF grant number DGE 1144152. TB and IK are supported by NCN grant 2014/15/Z/ST9/00038. We thank D Shoemaker, R Schofield, M Lintz and G Bogaert for comments on the manuscript. This article has been assigned LIGO Document number P1600306.
- Schumann resonances
- correlated noise
- gravitational waves