http://arxiv.org/abs/2012.01539
A common way to calculate the glitch activity of a pulsar is an ordinary linear regression of the observed cumulative glitch history. This method however is likely to underestimate the errors on the activity, as it implicitly assumes a (long-term) linear dependence between glitch sizes and waiting times, as well as equal variance, i.e. homoscedasticity, in the fit residuals, both assumption that are not well justified in pulsar data. In this paper, we review the extrapolation of the glitch activity parameter and explore two alternatives: the relaxation of the homoscedasticity hypothesis in the linear fit and the use of the bootstrap technique. Our main finding is a much larger uncertainty on activity estimates, with respect to that obtained with an ordinary linear regression. We discuss how this affects the theoretical upper bound on the moment of inertia associated to the region of a neutron star containing the superfluid reservoir of angular momentum released in a stationary sequence of glitches. We find that this upper bound is less tight if one considers the uncertainty on the activity estimated with the bootstrap method, and allows for models in which the superfluid reservoir is entirely in the crust.
A. Montoli, M. Antonelli, B. Haskell, et. al.
Fri, 4 Dec 20
62/77
Comments: 18 pages, 4 figures, comments welcome