1. Centre for Gravitational Astrophysics, Australian National University , Canberra, ACT 2601 , Australia
2. ARC Centre of Excellence for Gravitational Wave Discovery (OzGrav) , Hawthorn, VIC 3122 , Australia
3. CEDAR Audio Ltd , Cambridge CB21 5BS , UK
4. SUPA, University of Glasgow , Glasgow G12 8QQ , UK