Search results for: pulsars

Authors: Onuchukwu Chika Christian, Chukwude Augustine Ejike

Abstract:

We carried out a statistical analyse of microglitches events on a sample of radio pulsars. The distribution of microglitch events in frequency (ν) and first frequency derivatives ν˙ indicates that the size of a microglitch and sign combinations of events in ν and ν˙ are purely randomized. Assuming that the probability of a given size of a microglitch event occurring scales inversely as the absolute size of the event in both ν and ν˙, we constructed a cumulative distribution function (CDF) for the absolute sizes of microglitches. In most of the pulsars, the theoretical CDF matched the observed values. This is an indication that microglitches in pulsar may be interpreted as an avalanche process in which angular momentum is transferred erratically from the flywheel-like superfliud interior to the slowly decelerating solid crust. Analysis of the waiting time indicates that it is purely Poisson distributed with mean microglitch rate <γ> ∼ 0.98year^−1 for all the pulsars in our sample and <γ> / <∆T> ∼ 1. Correlation analysis, showed that the relative absolute size of microglitch event strongly with the rotation period of the pulsar with correlation coefficient r ∼ 0.7 and r ∼ 0.5 respectively for events in ν and ν˙. The mean glitch rate and number of microglitches (Ng) showed some dependence on spin down rate (r ∼ −0.6) and the characteristic age of the pulsar (τ) with (r ∼ −0.4/− 0.5).

Keywords: method-data analysis, star, neutron-pulsar, general

Procedia PDF Downloads 462

Authors: Ankita Jangid, K. Venkataratnam Kamma

Abstract:

This study develops closed-form solutions for Einstein's field equations for spherically symmetric anisotropic matter distribution, utilizing the space-time geometry of Finch-Skea. The resulting class of solutions can be employed as strong models for 4U 1820-30, 4U 1608‐52, and Cen X-3 pulsars by taking into account their physical admissibility. Graphical methods are employed to examine many physical characteristics of the model, including energy density, mass, pressures, anisotropy factor, equilibrium energy conditions, and stability analysis. This model allows a detailed analysis of the physical parameters and properties of the three compact objects.

Keywords: anisotropy factor, pulsars, stability analysis, finch-skea geometry

Procedia PDF Downloads 0