[1] CALTECH, LIGO Lab, Pasadena, CA 91125 USA
[2] Univ Birmingham, Sch Phys & Astron, Birmingham B15 2TT, W Midlands, England
[3] LIGO Hanford Observ, Richland, WA 99352 USA
[4] Univ Glasgow, Sch Phys & Astron, Inst Gravitat Res, Glasgow G12 8QQ, Lanark, Scotland
[5] Rutherford Appleton Lab, Dept Engn, Didcot OX11 0QX, Oxon, England
[6] Univ Strathclyde, Dept Phys, SUPA, Glasgow G4 0NG, Lanark, Scotland
[7] Univ W Scotland, SUPA, Thin Film Ctr, Paisley PA1 2BE, Renfrew, Scotland
[8] LIGO Livingston Observ, Livingston, LA 70754 USA
[9] MIT, LIGO Lab, Cambridge, MA 02139 USA