DETECTING GRAVITATIONAL WAVES USING MEERKAT'S PULSAR TIMING ARRAY_

Astrophysics
Data Science
Supercomputing

mentors

Prof. Matthew Bailes

Dr. Chris Flynn

Saurav Mishra

Contributors

Rudra Sekhri

Evie Spilias

Hendrik Combrinck

Rebecca Koehne

Ruoyao Ni

Pulsar timing arrays (PTAs) offer a new method to detect nano-hertz gravitational waves through a spatial correlation between the times of arrivals (ToAs) between pairs of pulsars. We report a preliminary detection of nHz gravitational waves using the Karoo Array Telescope (MeerKAT) PTA project. Our re-analysis used a sample of 8387 observations from 83 millisecond pulsars (MSPs) over the course of 4 years.

Credits

Report written by Rudra Sekhri and Hendrik Combrinck.

All members of this project contributed equally to the research phase of the project.

Specific credit to Robert, Hendrik and Rudra for working on checking detection significances using filtered samples of the final dataset, Evie and Rebecca for their work on chi2 distributions, Rudra for working on the data cleaning pipeline for both 16-band and 32-band arrival timing datasets, as well as the DM fitting and FD corrections processes to produce the final datasets. Also credits to Hendrik and Robert for developing new plotting tools in Python to quickly inspect and "interrogate" the data. Credit also goes to Saurav Mishra for his contributions in fixing the mean ToA offsets for each pulsar through the use of DM modelling through Gaussian processes, etc.

Thanks to Dr. Matt Miles, Dr. Daniel Reardon, Dr. Ryan Shannon for their immense contributions by providing the noise models and the code to search for Hellings-Downs correlations, as well as an in-depth understanding of how these noise models worked. Also thanks to Jacob Askew (Swinburne) for assisting in helping us understand the applications of high-frequency resolution pulsar timing data, especially, in the understanding properties of the interstellar medium through scintillation patterns in archive data.

Finally, thank you to Dr. Chris Flynn and Prof. Matthew Bailes for supervising this project. This project is funded by A.S.T.R.A.L..

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NOTE! This report was produced by the ASTRAL Student Team.

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