Journal article

On the Evidence for a Common-spectrum Process in the Search for the Nanohertz Gravitational-wave Background with the Parkes Pulsar Timing Array

Boris Goncharov, RM Shannon, DJ Reardon, G Hobbs, A Zic, M Bailes, M Curylo, S Dai, M Kerr, ME Lower, RN Manchester, R Mandow, H Middleton, MT Miles, A Parthasarathy, E Thrane, N Thyagarajan, X Xue, X-J Zhu, AD Cameron Show all



A nanohertz-frequency stochastic gravitational-wave background can potentially be detected through the precise timing of an array of millisecond pulsars. This background produces low-frequency noise in the pulse arrival times that would have a characteristic spectrum common to all pulsars and a well-defined spatial correlation. Recently the North American Nanohertz Observatory for Gravitational Waves collaboration (NANOGrav) found evidence for the common-spectrum component in their 12.5 yr data set. Here we report on a search for the background using the second data release of the Parkes Pulsar Timing Array. If we are forced to choose between the two NANOGrav models - one with a common-spect..

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University of Melbourne Researchers


Awarded by Australian Research Council (ARC) Centre of Excellence for Gravitational Wave Discovery (OzGrav)

Awarded by ARC

Funding Acknowledgements

This work has been carried out by the Parkes Pulsar Timing Array, which is part of the International Pulsar Timing Array. The Parkes radio telescope (Murriyang) is part of the Australia Telescope, which is funded by the Commonwealth Government for operation as a National Facility managed by CSIRO. This paper includes archived data obtained through the CSIRO Data Access Portal ( We acknowledge the use of CHAINCONSUMER (Hinton 2016). Parts of this research were conducted by the Australian Research Council (ARC) Centre of Excellence for Gravitational Wave Discovery (OzGrav), through project number CE170100004. R.M.S. acknowledges support through ARC future fellowship FT190100155. R.S. acknowledges support through the ARC Laureate fellowship FL150100148. The author list is based on three tiers, which correspond to primary contributors, to members of the collaboration who provided feedback, and to members of the collaboration with significant observing records. The dataprocessing code that was used in this work is available at