Preparing the International Pulsar Timing Array Third Data Release

In 2023, pulsar timing arrays (PTAs) around the world announced evidence for a nanohertz gravitational wave background. Now, under the auspices of the International Pulsar Timing Array, a combined dataset is in preparation, bringing together the data sets of the European Pulsar Timing Array, the Indian Pulsar Timing Array Experiment, the MeerKAT Pulsar Timing Array, the North American Nanohertz Observatory for Gravitational Waves, and the Parkes Pulsar Timing Array. The combined IPTA Third Data Release (DR3) will be the most sensitive PTA data set ever assembled and is expected to provide the first definitive detection of the low-frequency gravitational wave background. It will incorporate 121 pulsars, with as many as a dozen observatories contributing to the timing solutions, including new data from the Canadian Hydrogen Intensity Mapping Experiment (CHIME), the Low-Frequency Array (LOFAR), and the New Extension in Nançay Upgrading LOFAR (NenuFAR).

In this talk, we will share the ongoing progress on creating the world's best PTA data set, including information on new methods employed to manage the big data challenges IPTA DR3 present and to improve modeling of interstellar medium effects. We will also show preliminary pulsar timing results for DR3 pulsars.