Acknowledgments

AD acknowledges the award of a Research Excellence Scholarship from Macquarie University. QAP acknowledges support from Macquarie University and the Australian Astronomical Observatory (AAO). WS acknowledges support from grant UNAM-PAPIIT 101014. We would like to thank the staff at the ANU Siding Spring Observatory for their support. We acknowledge use of data from the VISTA telescope under ESO Survey programme ID 179.B-2002. We thank the anonymous referee whose suggestions and comments have greatly improved the paper.