The International Pulsar Timing Array
The International Pulsar Timing Array (IPTA) is an organisation whose raison d'etre is to facilitate collaboration between the three main existing PTAs (the EPTA in Europe, NANOGrav in North America and the PPTA in Australia) in order to realise the benefits of combined PTA data sets in reaching the goals of PTA projects. Currently, shared data sets for 39 pulsars are available for IPTA-based projects. Operation of the IPTA is administered by a Steering Committee consisting of six members, two from each PTA, plus the immediate past Chair in a non-voting capacity. A Constitution and several Agreements define the framework for the collaboration. Web pages provide information both to members of participating PTAs and to the general public. With support from an NSF PIRE grant, the IPTA facilitates the organisation of annual Student Workshops and Science Meetings. These are very valuable both in training new students and in communicating current results from IPTA-based research.