Reproducing the results for NICER observation of PSR J0030+0451

NASA's Neutron Star Interior Composition Explorer (NICER) observed X-ray emission from the pulsar PSR J0030+0451 in 2018. Riley \textit{et al.} reported Bayesian parameter measurements of the mass and the radius of the star using pulse-profile modeling of the X-ray data. In this paper, we reproduce their result using the open-source software \textit{X-PSI} and the publicly available data. We reproduce the main result within the expected statistical error. We note the challenges we faced in reproducing the results. We demonstrate that not only that the analysis can be reproduced, it can also be reused in future works by changing the prior distribution for the radius, and by changing the sampler configuration. We find no significant change in the measurement of the mass and radius, demonstrating that the original result is robust to these changes. Finally, we provide a containerized working environment that facilitates third-party reproduction of the measurements of mass and radius of PSR J0030+0451 using the NICER observations.